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POMEGRANATE

ترجمه این متن در ادامه مطلب

Punica granatum L.

Punicaceae

Common Names: Pomegranate, Granada (Spanish), Grenade (French).

Related Species: Punica proto-punica.

Origin: The pomegranate is native from Iran to the Himalayas in northern India and was cultivated and naturalized over the whole Mediterranean region since ancient times. It is widely cultivated throughout India and the drier parts of southeast Asia, Malaya, the East Indies and tropical Africa. The tree was introduced into California by Spanish settlers in 1769. In this country it is grown for its fruits mainly in the drier parts of California and Arizona.

Adaptation: Pomegranates prefer a semi-arid mild-temperate to subtropical climate and are naturally adapted to regions with cool winters and hot summers. A humid climate adversely affects the formation of fruit. The tree can be severely injured by temperatures below 12° F. In the U. S. pomegranates can be grown outside as far north as southern Utah and Washington, D.C. but seldom set fruit in these areas. The tree adapts well to container culture and will sometimes fruit in a greenhouse.

DESCRIPTION

Growth Habits: The pomegranate is a neat, rounded shrub or small tree that can grow to 20 or 30 ft., but more typically to 12 to 16 ft. in height. Dwarf varieties are also known. It is usually deciduous, but in certain areas the leaves will persist on the tree. The trunk is covered by a red-brown bark which later becomes gray. The branches are stiff, angular and often spiny. There is a strong tendency to sucker from the base. Pomegranates are also long-lived. There are specimens in Europe that are known to be over 200 years of age. The vigor of a pomegranate declines after about 15 years, however.

Foliage: The pomegranate has glossy, leathery leaves that are narrow and lance-shaped.

Flowers: The attractive scarlet, white or variegated flowers are over an inch across and have 5 to 8 crumpled petals and a red, fleshy, tubular calyx which persists on the fruit. The flowers may be solitary or grouped in twos and threes at the ends of the branches. The pomegranate is self-pollinated as well as cross-pollinated by insects. Cross-pollination increases the fruit set. Wind pollination is insignificant.

Fruit: The nearly round, 2-1/2 to 5 in. wide fruit is crowned at the base by the prominent calyx. The tough, leathery skin or rind is typically yellow overlaid with light or deep pink or rich red. The interior is separated by membranous walls and white, spongy, bitter tissue into compartments packed with sacs filled with sweetly acid, juicy, red, pink or whitish pulp or aril. In each sac there is one angular, soft or hard seed. High temperatures are essential during the fruiting period to get the best flavor. The pomegranate may begin to bear in 1 year after planting out, but 2-1/2 to 3 years is more common. Under suitable conditions the fruit should mature some 5 to 7 months after bloom.

CULTURE

Location: Pomegranates should be placed in the sunniest, warmest part of the yard or orchard for the best fruit, although they will grow and flower in part shade. The attractive foliage, flowers and fruits of the pomegranate, as well as its smallish size make it a excellent landscaping plant.

Soil: The pomegranate does best in well-drained ordinary soil, but also thrives on calcareous or acidic loam as well as rock strewn gravel.

Irrigation: Once established, pomegranates can take considerable drought, but for good fruit production they must be irrigated. To establish new plants they should be watered every 2 to 4 weeks during the dry season. The plants are tolerant of moderately saline water and soil conditions.

Fertilizing: In the West, the trees are given 2 to 4-ounce applications of ammonium sulfate or other nitrogen fertilizer the first two springs. After that very little fertilizer is needed, although the plants respond to an annual mulch of rotted manure or other compost.

Pruning: Plants should be cut back when they are about 2 ft. high. From this point allow 4 or 5 shoots to develop, which should be evenly distributed around the stem to keep the plant well balanced. These should start about 1 ft. from the ground, giving a short but well-defined trunk. Any shoots which appear above or below should be removed as should any suckers. Since the fruits are borne only at the tips of new growth, it is recommended that for the first 3 years the branches be judiciously shortened annually to encourage the maximum number of new shoots on all sides, prevent straggly development and achieve a strong well framed plant. After the 3rd year, only suckers and dead branches are removed.

Propagation: The pomegranate can be raised from seed but may not come true. Cuttings root easily and plants from them bear fruit after about 3 years. Twelve to 20 inches long cuttings should be taken in winter from mature, one-year old wood. The leaves should be removed and the cuttings treated with rooting hormone and inserted about two-thirds their length into the soil or into some other warm rooting medium. Plants can also be air-layered but grafting is seldom successful.

Pests and Diseases: Pomegranates are relatively free of most pests and diseases. Minor problems are leaf and fruit spot and foliar damage by white flies, thrips, mealybugs and scale insects. The roots are seldom bothered by gophers but deer will browse on the foliage.

Harvest: The fruits are ripe when they have developed a distinctive color and make a metallic sound when tapped. The fruits must be picked before over maturity when they tend to crack open, particularly when rained on. The pomegranate is equal to the apple in having a long storage life. It is best maintained at a temperature of 32° to 41° F. and can be kept for a period of 7 months within this temperature range and at 80 to 85% relative humidity without shrinking or spoiling. The fruits improve in storage, becoming juicier and more flavorful.

The fruit can be eaten out of hand by deeply scoring several times vertically and then breaking it apart. The clusters of juice sacs are then lifted out and eaten. The sacs also make an attractive garnish when sprinkled on various dishes. Pomegranate fruits are most often consumed as juice and can be juiced is several ways. The sacs can be removed and put through a basket press or the juice can be extracted by reaming the halved fruits on an ordinary orange juice squeezer. Another approach starts with warming the fruit slightly and rolling it between the hands to soften the interior. A hole is then cut in the stem end which is placed on a glass to let the juice run out, squeezing the fruit from time to time to get all the juice. The juice can be used in a variety of of ways: as a fresh juice, to make jellies, sorbets or cold or hot sauces as well as to flavor cakes, baked apples, etc. Pomegranate syrup is sold commercially as grenadine. The juice can also be made into a wine.

Commercial Potential: The primary commercial growing regions of the world are the Near East, India and surrounding countries and southern Europe. In California commercial cultivation is centered in the southern San Joaquin Valley. Consumer demand in this country is not great. More pomegranate fruits probably wind up as decorations in fruit bowls than are consumed.

CULTIVARS

Balegal

Originated in San Diego, Calif. Selected by Paul H. Thomson. Large, roundish fruit, 3 inches in diameter. Somewhat larger than Fleshman. Skin pale pink, lighter then Fleshman. Flesh slightly darker than Fleshman, very sweet.

Cloud

From the Univ. of Calif., Davis pomegranate collection. Medium-sized fruit with a green-red color. Juice sweet and white.

Crab

From the Univ. of Calif., Davis pomegranate collection. Large fruit have red juice that is tart but with a rich flavor. A heavy bearing tree.

Early Wonderful

Large, deep-red, thin-skinned, delicious fruit. Ripens about 2 weeks ahead of Wonderful. Medium-sized bush with large, orange-red fertile flowers. Blooms late, very productive.

Fleshman

Originated in Fallbrook, Calif. Selected by Paul H. Thomson. Large, roundish fruit, about 3 inches in diameter, pink outside and in. Very sweet flavor, seeds relatively soft, quality very good.

Francis

Originated in Jamaica via Florida. Large, sweet, split-resistant fruit. Prolific producer.

Granada

Originated in Lindsay, Calif. Introduced in 1966. Bud mutation of Wonderful. Fruit resembles Wonderful, but displays a red crown while in the green state, darker red in color and less tart. Ripens one month earlier than Wonderful. Flowers also deeper red. Tree identical to Wonderful.

Green Globe

Originated in Camarillo, Calif. Selected by John Chater. Large, sweet, aromatic, green-skinned fruit. Excellent quality.

Home

From the Univ. of Calif., Davis pomegranate collection. The fruit is variable yellow-red in color, with light pink juice that is sweet and of rich flavor. Some bitterness.

King

From the Univ. of Calif., Davis pomegranate collection. Medium to large fruit, somewhat smaller than Balegal and Fleshman. Skin darker pink to red. Flavor very sweet. Has a tendency to split. Bush somewhat of a shy bearer.

Phoenicia (Fenecia)

Originated in Camarillo, Calif. Selected by John Chater. Large fruit, 4-5 inches in diameter, mottled red-green skin. Flavor sweet, seeds relatively hard.

Sweet

Fruit is lighter in color than Wonderful, remains slightly greenish with a red blush when ripe. Pink juice, flavor much sweeter than other cultivars. Excellent in fruit punch. Trees highly ornamental, bears at an early age, productive.

Utah Sweet

Very sweet, good quality fruit. Pink skin and pulp. Seeds notably softer than those of Wonderful and other standard cultivars. Attractive pinkish-orange flowers.

Wonderful

Originated in Florida. First propagated in California in 1896. Large, deep purple-red fruit. Rind medium thick, tough. Flesh deep crimson in color, juicy and of a delicious vinous flavor. Seeds not very hard. Better for juicing than for eating out of hand. Plant is vigorous and productive. Leading commercial variety in California.

FURTHER READING

• Butterfield, Harry M. A History of Subtropical Fruits and Nuts in California. University of California, Agricultural Experiment Station. 1963.
• Facciola, Stephen. Cornucopia: a Source Book of Edible Plants. Kampong Publications, 1990. pp. 166-167.
• Johns, Leslie and Violet Stevenson, Fruit for the Home and Garden. Angus and Robertson, 1985. pp. 215-218.
• Morton, Julia F. Fruits of Warm Climates. Creative Resources Systems, Inc. 1987. pp. 352-355.
• Popenoe, Wilson. Manual of Tropical and Subtropical Fruits. Hafner Press. 1974. Facsimile of the 1920 edition. pp. 375-383.

See Index of CRFG Publications, 1969 - 1989 and annual indexes of Fruit Gardener for additional articles on the pomegranate

TAMARIND

Tamarindus indica L.

Leguminosae (Fabaceae)

Common Names: Tamarind, Tamarindo, Tamarin, Sampalok.

Distant affinity: Carob (Ceratonia siliqua).

Origin: The tamarind is native to tropical Africa and grows wild throughout the Sudan. It was introduced into India so long ago, it has often been reported as indigenous there also. It is extensively cultivated in tropical areas of the world. Sometime during the sixteenth century, it was introduced into America and today is widely grown in Mexico.

Adaptation: The tamarind is well adapted to semiarid tropical conditions, although it does well in many humid tropical areas of the world with seasonally high rainfall. Young trees are very susceptible to frost, but mature trees will withstand brief periods of 28° F without serious injury. A tamarind tree in the Quail Botanical Gardens in San Diego County flowers, but rarely sets fruit, possibly because of the cool coastal climate. Dry weather is important during the period of fruit development. The tree is too large to be grown in a container for any length of time.

DESCRIPTION

Growth Habit: Tamarinds are slow-growing, long-lived, evergreen trees that under optimum conditions can grow 80 feet high with a spread of 20 to 35 ft., in its native eastern Africa and Asia. However, in Southern California it seldom reaches more than 15 to 25 ft. in height.

Foliage: The bright green, pinnate foliage is dense and feathery in appearance, making an attractive shade tree with an open branch structure. The leaves are normally evergreen but may be shed briefly in very dry areas during the hot season. There are usually as many as 10 to 20 nearly sessile 1/2 - 1 inch, pale green leaflets per leaf. The leaflets close up at night.

Flowers: The inconspicuous, inch-wide, five-petalled flowers are borne in small racemes and are yellow with orange or red streaks. The flower buds are pink due to the outer color of the 4 sepals which are shed when the flower opens.

Fruit: The 3 - 8 inch long, brown, irregularly curved pods are borne in abundance along the new branches. As the pods mature, they fill out somewhat and the juicy, acidulous pulp turns brown or reddish-brown. When fully ripe, the shells are brittle and easily broken. The pulp dehydrates to a sticky paste enclosed by a few coarse stands of fiber. The pods may contain from 1 to 12 large, flat, glossy brown, obovate seeds embedded in the brown, edible pulp. The pulp has a pleasing sweet/sour flavor and is high in both acid and sugar. It is also rich in vitamin B and high in calcium. There are wide differences in fruit size and flavor in seedling trees. Indian types have longer pods with 6 - 12 seeds, while the West Indian types have shorter pods containing only 3 - 6 seeds. Most tamarinds in the Americas are of the shorter type.

CULTURE

Location: The tamarind ultimately becomes a fairly large tree, so this should be kept in mind when planting out the tree. It should be planted in full sun and is highly wind-resistant with strong, supple branches. The tree generally forms a beautiful spreading crown that casts a light shade.

Soils Tamarinds tolerate a great diversity of soil types but do best in deep, well drained soils which are slightly acid. Trees will not tolerate cold, wet soils but are tolerant of salt spray and can be planted fairly near the seashore.

Irrigation: The tamarind is adapted to semiarid regions of the tropics and can withstand drought conditions quite well. Young trees require adequate soil moisture until they become established, but mature trees do quite well without supplemental irrigation. Avoid over-watering which results in soggy soils.

Fertilization: The tamarind is not very demanding in its nutritional requirements. Young trees should be fertilized every 2 - 3 months with a 6-6-3 NPK or similar analysis fertilizer. Apply 1/4 lb. and gradually increase to about 1/2 lb. Thereafter, young trees should receive 1/2 lb. per application, per year of tree age, 3 - 4 times a year. Bearing trees can be fertilized with 8-3-9 NPK or similar analysis, at rates of about 1/2 lb. per application per year of tree age. Microelements, particularly iron may be required for trees in alkaline soils.

Pruning: Young trees are pruned to allow three to five well spaced branches to develop into the main scaffold structure of the tree. Maintenance pruning only is required after that to remove dead or damaged wood.

Propagation: Rootstocks are propagated from seed, which germinate within a week. Seeds retain their viability for several months if kept dry. Plant seeds 1/2 inch deep in containers filled with a UC soilless type potting media. They should be selected from trees of good production and quality. Even so, seedlings will be variable in quality and slow to bear. Veneer grafting, shield (T or inverted T) budding and air layering may be used to propagate desirable selections. Such trees will usually fruit within 3 - 4 years if provided optimum growing conditions. Seedlings should begin to produce fruit in 6 - 8 years, while vegetatively propagated trees will normally bear in half that time.

Young trees should be planted in holes larger than necessary to accommodate the root system. They should be planted slightly higher than existing ground level to allow for subsequent settling of the soil and a water basin should be built around each tree to assure adequate moisture for young trees. Spacing of trees is normally 20 to 25 ft. in commercial orchards. However, solitary trees planted in Southern California rarely exceed 15 feet in diameter.

Pests and Diseases: In California tamarinds are generally free of pests and diseases, although ants will sometimes spread black and olive scales. In India there are are a host of pests that attack the tree, including mealybugs, caterpillars, aphids, white flies, thrips and a variety of scales. Various weevils and borers can also infest the ripening pods or stored fruits.

Harvest: Tamarind fruits mature in late spring to early summer. They may be left on the tree for as long as 6 months after maturity so that the moisture content will be reduced to 20% or lower. Fruits for immediate processing are often harvested by pulling the pod away from the stalk. Mature trees are capable of producing 350 lb. of fruit a year. Ripe fruit in humid climates is readily attacked by beetles and fungi, so mature fruit should be harvested and stored under refrigeration.

Tamarinds may be eaten fresh, but they area most commonly used with sugar and water in the American tropics to prepare a cooling drink. The pulp is used to flavor preserves and chutney, to make meat sauces ant to pickle fish. Candy can be made by mixing the pulp with dry sugar and molding it into desired shapes.

CULTIVARS

There are selected cultivars which have sweeter pulp. One in Thailand is Makham Waan and the USDA's subtropical horticulture research unit in Miami, Florida has one called Manila Sweet. None are presently available in Southern California.

FURTHER READING

• Morton, Julia F. Fruits of Warm Climates. Creative Resources Systems, Inc. 1987. pp. 115-121.
• Popenoe, Wilson. Manual of Tropical and Subtropical Fruits. Hafner Press. 1974. Facsimile of the 1920 edition. pp. 432-436.

See Index of CRFG Publications, 1969 - 1989 and annual indexes of Fruit Gardener for additional articles on the tamarind

BANANA

Musa species

Musaceae

Common Names: Banana, Bananier Nain, Canbur, Curro, Plantain

Origin: Edible bananas originated in the Indo-Malaysian region reaching to northern Australia.

Species: Musa acuminata Colla, M. X paradisiaca L. (hybrid)

Related species Abyssinian Banana (Ensete ventricossum Cheesman), Musa balbisina Colla, M. ornata Roxb., M. textilis Nee

Adaptation Bananas and plantains are today grown in every humid tropical region and constitutes the 4th largest fruit crop of the world. The plant needs 10 - 15 months of frost-free conditions to produce a flower stalk. All but the hardiest varieties stop growing when the temperature drops below 53° F. Growth of the plant begins to slow down at about 80° F and stop entirely when the temperature reaches 100° F. High temperatures and bright sunlight will also scorch leaves and fruit, although bananas grow best in full sun. Freezing temperatures will kill the foliage. In most areas bananas require wind protection for best appearance and maximum yield. They are also susceptible to being blown over. Bananas, especially dwarf varieties, make good container specimens if given careful attention. The plant will also need periodic repotting as the old plant dies back and new plants develop.

DESCRIPTION

Growth Habit: Bananas are fast-growing herbaceous perennials arising from underground rhizomes. The fleshy stalks or pseudostems formed by upright concentric layers of leaf sheaths constitute the functional trunks. The true stem begins as an underground corm which grows upwards, pushing its way out through the center of the stalk 10-15 months after planting, eventually producing the terminal inflorescence which will later bear the fruit. Each stalk produces one huge flower cluster and then dies. New stalks then grow from the rhizome. Banana plants are extremely decorative, ranking next to palm trees for the tropical feeling they lend to the landscape.

Foliage: The large oblong or elliptic leaf blades are extensions of the sheaths of the pseudostem and are joined to them by fleshy, deeply grooved, short petioles. The leaves unfurl, as the plant grows, at the rate of one per week in warm weather, and extend upward and outward , becoming as much as 9 feet long and 2 feet wide. They may be entirely green, green with maroon splotches, or green on the upper side and red-purple beneath. The leaf veins run from the mid-rib straight to the outer edge of the leaf. Even when the wind shreds the leaf, the veins are still able to function. Approximately 44 leaves will appear before the inflorescence.

Flowers: The banana inflorescence shooting out from the heart in the tip of the stem, is at first a large, long-oval, tapering, purple-clad bud. As it opens, the slim, nectar-rich, tubular, toothed, white flowers appear. They are clustered in whorled double rows along the the floral stalk, each cluster covered by a thick, waxy, hood like bract, purple outside and deep red within. The flowers occupying the first 5 - 15 rows are female. As the rachis of the inflorescence continues to elongate, sterile flowers with abortive male and female parts appear, followed by normal staminate ones with abortive ovaries. The two latter flower types eventually drop in most edible bananas.

Fruits: The ovaries contained in the first (female) flowers grow rapidly, developing parthenocarpically (without pollination) into clusters of fruits, called hands. The number of hands varies with the species and variety. The fruit (technically a berry) turns from deep green to yellow or red, and may range from 2-1/2 to 12 inches in length and 3/4 to 2 inches in width. The flesh, ivory-white to yellow or salmon-yellow, may be firm, astringent, even gummy with latex when unripe, turning tender and slippery, or soft and mellow or rather dry and mealy or starchy when ripe. The flavor may be mild and sweet or subacid with a distinct apple tone. The common cultivated types are generally seedless with just vestiges of ovules visible as brown specks. Occasionally, cross-pollination with wild types will result in a number of seeds in a normally seedless variety.

CULTURE

Location: Bananas require as much warmth as can be given them. Additional warmth can be given by planting next to a building. Planting next to cement or asphalt walks or driveways also helps. Wind protection is advisable, not for leaf protection as much as for protection of the plant after the banana stalk has appeared. During these last few months propping should be done to keep the plant from tipping or being blown over.

Soil: Bananas will grow in most soils, but to thrive, they should be planted in a rich, well-drained soil. The best possible location would be above an abandoned compost heap. They prefer an acid soil with a pH between 5.5 and 6.5. The banana is not tolerant of salty soils.

Irrigation: The large leaves of bananas use a great deal of water. Regular deep watering is an absolute necessity during warm weather. Do not let plants dry out, but do not overwater. Standing water, especially in cool weather, will cause root rot. Plants grown in dry summer areas such as Southern California need periodic deep waterings to help leach the soil of salts. Spread a thick layer of mulch on the soil to help conserve moisture and protect the shallow roots. Container grown plants should be closely watched to see that they do not dry out. An occasional deep watering to leach the soil is also helpful.

Fertilization: Their rapid growth rate make bananas heavy feeders. During warm weather, apply a balanced fertilizer once a month--a 8:10:8 NPK fertilizer appears to be adequate. A mature plant may require as much as 1-1/2 to 2 pounds of the above fertilizer each month. Young plants need a quarter to a third as much. Spread the fertilizer evenly around the plant in a circle extending 4 - 8 feet from the trunk. Do not allow the fertilizer to come in contact with the trunk. Feed container container plants on the same monthly schedule using about half the rate for outside plants.

Frost Protection: Bananas flourish best under uniformly warm conditions but can survive 28° F for short periods. If the temperature does not fall below 22° F and the cold period is short, the underground rhizome will usually survive. To keep the plants that are above ground producing, protection against low temperatures is very important. Wrap trunk or cover with blanket if the plants are small and low temperatures are predicted.

Pruning Only one primary stem of each rhizome should be allowed to fruit. All excess shoots should be removed as soon as they are noticed. This helps channel all of of the plant's energy into fruit production. Once the main stalk is 6 - 8 months old, permit one sucker to develop as a replacement stalk for the following season. When the fruit is harvested, cut the fruiting stalk back to 30 inches above the ground. Remove the stub several weeks later. The stalk can be cut into small pieces and used as mulch.

Propagation: Propagation of bananas is done with rhizomes called suckers or pups. Very small pups are called buttons. Large suckers are the preferred planting material. These are removed from vigorous clumps with a spade when at least three feet tall, during warm months. Pups should not be taken until a clump has at least three to four large plants to anchor it. When the pup is taken the cut must be into the mother plant enough to obtain some roots. Plant close to the surface. Large leaves are cut off of the pup leaving only the youngest leaves or no leaves at all. Some nurseries supply banana plants as container grown suckers.

Pests and Diseases: Bananas have few troublesome pests or diseases outside the tropics. Root rot from cold wet soil is by far the biggest killer of banana plants in our latitudes. California is extremely fortunate in not having nematodes that are injurious to the banana. Gophers topple them, and snails and earwigs will crawl up to where they can get continuous water, but these pests do not bother the plant.

Fruit Harvest: Stalks of bananas are usually formed in the late summer and then winter over. In March they begin "plumping up" and may ripen in April. Occasionally, a stalk will form in early summer and ripen before cold weather appears. The fruit can be harvested by cutting the stalk when the bananas are plump but green. For tree-ripened fruit, cut one hand at a time as it ripens. If latter is done, check stalk daily as rodents can eat the insides of every banana, from above, and the stalk will look untouched. Once harvested the stalk should be hung in a cool, shady place. Since ethylene helps initiate and stimulate ripening, and mature fruit gives off this gas in small amounts, ripening can be hastened by covering the bunch with a plastic bag. Plantains are starchy types that are cooked before eating.

CULTIVARS

The antiquity of the banana and its tendency to produce mutations or sports have resulted in an extensive number of cultivars. Only the common ones growing in California are listed.

Apple, Silk, or Manzana

Dessert type, pleasant sub-acid apple flavor when fully ripe. Fruit: 4 to 6 inches. Grows to 10 to 12 feet. The fruit is not ripe until some brownish specs appear on the skin. From planting until harvest is approximately 15 months.

Cavendish

Resistant to Panama Wilt disease. Clones of this variety are distinguished by the size of the pseudostem. The largest is Lacatan (12 to 18 feet) followed by Robusta and Giant Cavendish (10 to 16 feet). The smallest is the Dwarf Cavendish (4 to 7 feet).

Cuban Red

Very tall (up to 25 feet), very tropical. Skin dark red, with generally reddish pseudostem. Fruit is especially aromatic with cream-orange pulp. 20 months from planting until harvest.

Gros Michel

Commercially, the most important and considered by many to be the most flavorful. Because of its susceptibility to Panama Wilt disease it is being replaced with resistant varieties. Although there is no Panama Wilt in California, it does poorly here as the plant seems to need more heat and it tends to grow more slowly than other varieties

Ice Cream or Blue Java

Medium-tall (15 to 20 feet), bluish cast to the unripe fruit. Fruit: 7 to 9 inches, quite aromatic and is said to melt in the mouth like ice cream. Bunches are small with seven to nine hands. 18 to 24 months from planting until harvest.

Lady Finger

Tall (20 to 25 feet), excellent-quality fruit, tolerant of cool conditions. 15 to 18 months from planting to harvest.

Orinoco

Commonly grown in California for years as a landscape plant. Grows to 16 feet, more cold hardy than any other. 15 to 18 months from planting to harvest. Flavor is good, texture is less than perfect, but when properly grown and cultivated it can produce enormous stalks of fruit. Excellent in banana bread. Sometimes called horse, hog or burro banana, it can be purchased at most nurseries.

Popoulu

A Hawaiian variety with short, salmon-pink flesh, plump fruit that may be cooked or eaten fresh. A slender plant preferring a protected area with high humidity and filtered light. Grows to about 14 feet tall.

Valery

A Cavendish clone resembling the Robusta. Some believe them to be the same. The Dwarf Cavendish is the most widely planted as it is better adapted to a cool climate and is less likely to be blown over.

Williams

The same as Giant Cavendish. Originated from a mutation of Dwarf Cavendish found in Queensland, Australia. A commercial banana grown in many countries that does well in California. 10 to 16 feet in height and has a distinctive long, very large bud. The Del Monte is a Williams.

FURTHER READING

• Lessard, William O. Complete Book of Bananas. William O. Lessard, Publisher. 1992
• Morton, Julia F. Fruits of Warm Climates. Creative Resources Systems, Inc. 1987. pp. 29-46
• Ortho Books. All About Citrus and Subtropical Fruits. Chevron Chemical Co. 1985. pp. 20-23

See Index of CRFG Publications, 1969 - 1989 and annual indexes of Fruit Gardener for additional articles on the banana

PINEAPPLE

Ananas comosus

Bromeliaceae

Common Names: Pineapple, Ananas, Nanas, Pina.

Related Species: Pina de Playon (Ananas bracteatus).

Distant affinity: Pingwing (Aechmea magdalenae), Pinguin (Bromelia pinguin), Pinuela (Karatas plumier).

Origin: The pineapple is native to southern Brazil and Paraguay where wild relatives occur. It was spread by the Indians up through South and Central America to the West Indies before Columbus arrived. In 1493 Columbus found the fruit on the island of Guadaloupe and carried it back to Spain and it was spread around the world on sailing ships that carried it for protection against scurvy. The Spanish introduced it into the Philippines and may have taken it to Hawaii and Guam early in the 16th Century. The pineapple reached England in 1660 and began to be grown in greenhouses for its fruit around 1720.

Adaptation: The pineapples is a tropical or near-tropical plant, but will usually tolerate brief exposures to 28° F. Prolonged cold above freezing retards growth, delays maturity and causes the fruit to be more acid. Pineapples are drought-tolerant and will produce fruit under yearly precipitation rates ranging from 25 - 150 in., depending on cultivar and location and degree of atmospheric humidity. They are successfully grown in southern Florida and coastal areas of southern California. The small plant adapts well to container and greenhouse culture and makes an interesting potted plant.

DESCRIPTION

Growth Habit: The pineapple plant is a herbaceous perennial, 2-1/2 to 5 ft. high with a spread of 3 to 4 ft. It is essentially a short, stout stem with a rosette of waxy, straplike leaves.

Foliage: The long-pointed leaves are 20 - 72 in. in length, usually needle tipped and generally bearing sharp, upcurved spines on the margins. They may be all green or variously striped with red, yellow or ivory down the middle or near the margins. As the stem continues to grow, it acquires at its apex a compact tuft of stiff, short leaves called the crown or top. Occasionally a plant may bear 2 or more heads instead of the normal one.

Flowers: At blooming time, the stem elongates and enlarges near the apex and puts forth an inflorescence of small purple or red flowers. The flowers are pollinated by humming-birds, and these flowers usually develop small, hard seeds. Seeds are generally not found in commercially grown pineapple.

Fruit: The oval to cylindrical-shaped, compound fruit develops from many small fruits fused together. It is both juicy and fleshy with the stem serving as the fibrous core. The tough, waxy rind may be dark green, yellow, orange-yellow or reddish when the fruit is ripe. The flesh ranges from nearly white to yellow. In size the fruits are up to 12 in. long and weigh 1 to 10 pounds or more.

CULTURE

Location: Pineapples should be planted where the temperature remains warmest, such as the south side of a home, or in a sunny portion of the garden.

Soil: The best soil for the pineapple is a friable, well-drained sandy loam with a high organic content. The pH should be within a range of 4.5 to 6.5. Soils that are not sufficiently acid can be treated with sulfur to achieve the desired level. The plant cannot stand waterlogging and if there is an impervious subsoil, drainage needs to be improved.

Irrigation: The plant is surprisingly drought tolerant, but adequate soil moisture is necessary for good fruit production.

Fertilization: Nitrogen is essential to increase fruit size and total yield, which should be added every four months. Spraying with a urea solution is another way to supply nitrogen. Fruit weight has also been increased by the addition of magnesium. Of the minor elements, iron is the most important, particularly in high pH soils. Iron may be supplied by foliar sprays of ferrous sulfate.

Frost Protection: Pineapple plants require a frost-free environment. They are small enough to be easily covered when frost threatens, but cold weather adversely affects the fruit quality.

Propagation: Pineapples are propagated by new vegetative growth. There are four general types: slips that arise from the stalk below the fruit, suckers that originate at the axils or leaves, crowns that grow from the top of the fruits, and ratoons that come out from the under-ground portions of the stems.

Although slips and suckers are preferred, crowns are the main planting material of home gardeners. These are obtained from store-bought fruit and are removed from the fruit by twisting the crown until it comes free. Although the crown may be quartered to produce four slips, in California's marginal conditions it is best not to cut or divide the crown. The bottom leaves are removed and the crown is left to dry for two days, then planted or started in water.

Pineapples are planted outside during the summer months. A ground cover of black plastic works very well for pineapples, both as protection from weeds and for the extra heat it seems to absorb. It also helps to conserve moisture. Traditionally, plants are spaced 12 inches apart. Set crowns about 2 inches deep; suckers and slips 3 to 4 inches deep.

Pests and diseases: Mealybugs spread by ants can be a problem. Controling the ants will control the mealybugs. In most commercial growing areas, nematodes, mites and beetles can also be damaging, but these have not been a problem in California.

Harvest: It is difficult to tell when the pineapple is ready to be harvested. Some people judge ripeness and quality by snapping a finger against the side of the fruit. A good, ripe fruit has a dull, solid sound. Immaturity and poor quality are indicated by a hollow thud. The fruit should be stored at 45° F or above, but should be stored for no longer than 4 - 6 weeks.

Misc.: Fruiting can be forced when the plant is mature by using acetylene gas or a spray of calcium carbide solution (30 gms to 1 gal. water), which produces acetylene. Or calcium carbide (10 -12 grains) can be deposited in the crown of the plant to be dissolved by rain. A safer and more practical method for home growers is a foliar spray of a-naphthaleneacetic acid (1 gm in 10 gal water) or B-hydroxyethyl hydrazine. The latter is more effective. The plants usually produce for about four years, but they may last longer in California since the life cycle is slowed down by cooler weather.

CULTIVARS

Hilo

A compact 2-3 lb. Hawaiian variant of the Smooth Cayenne. The fruit is more cylindrical and produces many suckers but no slips.

Kona Sugarloaf

5-6 lbs, white flesh with no woodiness in the center. Cylindrical in shape, it has a high sugar content but no acid. An incredibly delicious fruit.

Natal Queen

2-3 lbs, golden yellow flesh, crisp texture and delicate mild flavor. Well adapted to fresh consumption. Keeps well after ripening. Leaves spiny.

Pernambuco (Eleuthera)

2-4 lbs with pale yellow to white flesh. Sweet, melting and excellent for eating fresh. Poorly adapted for shipping. Leaves spiny.

Red Spanish

2-4 lbs, pale yellow flesh with pleasant aroma; squarish in shape. Well adapted for shipping as fresh fruit to distant markets. Leaves spiny.

Smooth Cayenne

5-6 lbs, pale yellow to yellow flesh. Cylindrical in shape and with high sugar and acid content. Well adapted to canning and processing. Leaves without spines. This is the variety from Hawaii, and the most easily obtainable in U. S. grocery stores.

FURTHER READING

• Morton, Julia F. Fruits of Warm Climates. Creative Resources Systems, Inc. 1987. pp. 18-28.
• Maxwell, Lewis S. and Betty M. Maxwell. Florida Fruit. Lewis S. Maxwell, Publisher. 1984. pp. 12-14.
• Samson, J. A. Tropical Fruits. 2nd ed. Longman Scientific and Technical. 1986. pp. 190-215.

See Index of CRFG Publications, 1969 - 1989 and annual indexes of Fruit Gardener for additional articles on the pineapple

KIWIFRUIT

Actinidia deliciosa

Actinidiaceae

Common Names: Kiwifruit, kiwi, Chinese gooseberry, Yang-tao.

Related species: Hardy Kiwi (Actinidia arguta, A. kolomikta), Chinese Egg Gooseberry (A. coriacea), Red Kiwi (A. melanandra), Silver Vine (A. polygama), Purple Kiwi (A. purpurea).

Origin: The kiwifruit is native to the Yangtze River valley of northern China and Zhejiang Province on the coast of eastern China. The first seeds were brought out of China by missionaries to New Zealand at the turn of this century. Early nurserymen in New Zealand, such as Alexander Allison, Bruno Just, and Hayward Wright, recognized the potential of the fruit and it soon became a popular backyard vine. Several plants were sent to the Chico Plant Introduction Station in California and exist to this date. In addition to New Zealand and California, kiwifruit is also grown commercially in such areas as Italy, South Africa and Chile.

Adaptation: The plants need a long growing season (at least 240 frost-free days) which will not be hampered by late winter or early autumn freezes. When fully dormant they can withstand temperatures to about 10° F (and perhaps a bit lower.) However they must acclimate to cold slowly and any sudden plunge in temperature may cause trunk splitting and subsequent damage to the vine. Late winter freezing temperatures will kill any exposed buds which limits the adaptable growing areas of kiwifruit. In California the kiwifruit is an appropriate crop wherever citrus fruits, peaches and almonds are successful. All cultivars need a certain period of winter chilling and their needs vary dramatically, dependent upon cultivar. The most popular cultivar, Hayward, does best with a winter rest of 800 hours of chilling (defined as total hours between 32° and 45° F.) For warm winter areas with low chill hours (such as southern California, southern Texas, and Florida), cultivars such as Elmwood, Dexter, Abbott, or Vincent would be more suitable. In very mild winter areas the vines may retain their leaves and fail to flower the following season. Kiwi vines can be successfully grown in large containers.

DESCRIPTION

Growth Habit: In the forests where it is native, the plant is a vigorous, woody, twining vine (liana) or climbing shrub. It is not unusual for a healthy vine to cover an area 10 to 15 feet wide, 18 to 24 feet long and 9 to 12 feet high. In cultivation it is supported on a trellising system.

Foliage: The large, deep green, leathery leaves are oval to nearly circular and 7 to 10 inches in diameter. Young leaves and shoots are coated with red hairs, while mature leaves are dark green and hairless on the upper surface, downy-white with prominent, light colored veins beneath.

Flowers: The large (1 to 2 inch diameter), white to cream colored flowers are somewhat fragrant and produced as singlets to triplets in the leaf axiles. The flowering period extends over several weeks from early May to June, depending on climatic conditions. The plants are dioecious, bearing either male or female flowers, thus needing plants of both sexes to produce fruit. Self-fruiting males are known to exist but produce less desirable fruit.

Fruit: The oval, ovoid or oblong fruit is up to 2-1/2 inches long, with russet-brown skin densely covered with short, stiff brown hairs. The flesh, firm until fully ripe, is glistening, bright green or sometimes yellow, brownish or off-white, except for the white, succulent center from which radiate many fine, pale lines. Between these lines are scattered minute dark-purple or nearly black seeds, unnoticeable in eating. The flavor is sweet/tart to acid, somewhat like that of the gooseberry with a suggestion of strawberry.

on the kiwifrui

It is the policy of the Purdue University Cooperative Extension Service, David C. Petritz, Director, that all persons shall have equal opportunity and access to programs and facilities

u disabled with a need for easy accessability

u gardeners with problem soil

u homeowners with little or no land

u elderly with limited mobility

u apartment/condominium dwellers

u cooks—gourmet and otherwise

u plant lovers who just can’t get enough of nature

Plants suited for container culture*

Annuals Anise Dill

Biennials Caraway Parsley

Perennials Chives Mint

Fall-planted Crocus Scilla

Spring-planted Begonia Gladiolus

* Consult catalogs for cultural requirements and

Bartholomew, Mel Square Foot Gardening, St.

Berry, Susan and Bradley, Steve Contained

Gardens, Ballentine Fawcett, Division of

Holmes, Roger Taylors Guide to Container

Gardening, Houghton Mifflin, Boston, MA, 1995.

Yang, Linda The City Gardeners Handbook,

گروه : زراعت غلات - بیوشیمی گیاهی - فیزیولوژی گیاهان

whereas the products of co2 assimilation are deposited in plants in the

from of oligo-and polysaccharides as discussed in chapter 9the  amino acids formed as products of nitrate assimilation are stored as proteins this are mostly special storage proteine which have no .  enzymatic activity and are often deposited in the cell within protein bodies   

protein bodies are enclosed by a single membrane and are derived from the endomembrane system of the endoplasmic reticulum and the golgi apparatus or the vacuoles. in potato tubers storage proteins are also stored in the vacuole

stems and roots they are stored in seeds and tubersand also in the cambium of tree trunks during winter to enable the rapid formation of leaves during seed germination and sprouting.

storage proteins are located in the endosperm in cereal seeds and in the cotyledons of most of the legume seeds.

whereas in cereals the protein content amounts to 10% to 15% of the dry weight in some legumes it is as high as 40 to 50 about 85 of these proteins are storage proteins

globally about 70% of the human demand for protein is met by the consumption of seeds either directly or indirectly by feeding them to animal for meat production therefore plant storage proteins are the basis for human nutrition however in many plant storage proteins the content of certain amino acids essential for the nutrition of humans and animals is too low in cereals for example the storage proteins are deficient in threonine tryptophan and particularly lysine whereas in legumes there is adeficiency of mehionine. since these amino acids cannot be synthesized by human metabolism humans depend on being supplied with them in their food

in humans with an entirely vegetarian diet such amino acid deficiencies can lead to irreparable physical and mental damage especially in childeren. it can also be aserious problem in pig and poultry feed. a target of research in plant genetic engineering is to improve the amino acid composition of the storage proteins of harvest products

scientists have long been interested in plant proteines by 1745 the italian ()already had isolated proteins from wheat. in 1924, at the connecticut agricultural experimental station, t. b. osborne classified plant proteins according to their solubility properties.he fractionated plant proteins into albumins (soluble in pure water ), globulins (soluble in diluted salt solutions), glutelins (soluble in diluted solutions of alkali and acids), and prolamins (soluble in aqueous ethanol).

when the structures of these proteins were determined later, it turned out that glutelins and prolamins were structurally closely related. therefore, in more recent literrature, glutelins are regarded as members of the group of prolamins. table 14.1shows some examples of various plant storage proteins.

14.1 globulins are the most abundant storage proteins

storage globulins occur in varying amounts in practically all plants. the most important globulins belong to the legumin and groups. both of these globulins are encoded by amultigene family.these multigene families descend from a common ancestor. legumin is the main storage protein of leguminous seeds. in broad bean, for instance, 75% of the total storage protein consists of legumin. legumin is a hexamer with a molecular mass of 300to 400 k da. the monomers contain two diffrent peptide chains (      ) which are linked by a disulfide bridge. the large alfa-chain usually has a molecular mass of about 35 to 40 k da, and the small beta-chain has a molecular mass of about 20 k da. hexamers can be composed of different (   )monomers. some contain methionine, whereas other do not. in the hexamer, the protein molecules are arranged in avery regular package and can be deposited in this form in the protein bodies. protein molecules, in which some of the protein chains are not properly folded, do not fit into this package and are degraded by peptidases. although it is relatively easy nowadays to exchang amino acids in a protein by genetic engineering, this has turned out to be difficult in storage proteins. as both the folding and the three-dimensional structure of the molecule may be altered by such exchange. recent progress in obtaining crystals enabled the analysis of the three-dimensional protein structure of the precursor trimers as well as of the mature storage proteins. these studies revealed that the stability of the storage proteins toward the proteases in the storage vacuoles is due to the fact that possible cleavage sites are hidden within the protein structure and in this way are protected against proteolysis.

vicilin shows similarities in its amino acid sequence to legumine, but occurs mostly as a trimer, of which the monomers consist of only one peptidechain. due to the lack of cystenine, the vicillin monomers are unable to form s-s bridges. in contrast legumins, viclins are often glycosylated: they contain carbohydrate residues,such as mannose, glucose, and n-acetylglucosamine.

14.2 prolamins are formed as storage proteins in grasses.

prolamins are contained only in grasses, such as cereals. they are present as a polymorphic mixture many different subunits of 30to 90 kda each. some of these subunits contain cysteine residues and are linked by s-sbridges. also in glutenin, which occurs in the grains of wheat and rye, monomers are linked by s-sbridges. the glutenin molecules differ in size. the suitability of flour for bread-making depends on the content of high molecular glutenins, and therefore flour from barley, oat, ormaize lacking glutenin, is not suitable for baking bread. since the glutenin content is a critical factor in determining the quality of bread grain, investigations are progress to improve the glutenin content of bread grain by genetic engineering.

14.3  2s-proteins are present in seeds of dicot plants.

2s-proteins are also widely distributed storage proteins. they represent a heterogeneous group of proteins, of which the sole definition is their sedimentation coefficient of about 2 svedberg(s). investigations of their structure have revealed that most 25-proteins have an interrelated structure and are possibly derived, along with the prolamins, from a common ancestor protein. napin, the predominant storage protein in rapeseed, is an example of a 25-protein is of substantial economic importanc since, after the oil has been extracted, the remainder of the rapeseed is used as fodder, napin and other related 25-proteins consist of two relatively small polypeptide chains of 9 k da and12 k da,which are linked by s-s bridges. so far, little is know about the packing of the prolamins and 25-proteins in the protein bodies.

14.4  special proteins protect seeds from being eaten by animals.

the protein bodies of some seeds contain other proteins, which, although also acting as storage proteins, protect the seeds from being eaten. to give some examples: the storage protein vieillin has a defense function by binding to the chitin matrix of fungi and insects. in some insects, it interferes with the development of the larvae. the seeds of some legumes contain leetins, which bind to sugar residues, irrespective of whether these are free sugarsor constituents of glycolipids or glycoproteins. when these seeds are consumed by animals, the lectins bind to glycoproteins in the intestine and thus interfere with the absorption of food. the seeds of some legumes and other plans also contain proteinase inhibitors, which block the digestion of proteins by inhibiting proteinases in the animal digestive tract. because of their content of lectins and proteinase inhibitors, many beans and other plant products are suitable for human consumption only after denaturing by cooking. this is one reason why humans have learned to cook. castor beans contain the extremely toxic protein ricin. a few mg of it can kill a human. beans also contain amylase inhibitors, which specifically inhibit the hydrolysis of starch by amylases in the digestive tract of certain insects.

using genetic engineering, alpha-amylase inhibitors from beans successfully expressed in the seeds of pea. whereas the larvae of the pea beetle normally cause large losses during storage of peas, the peas from the genetically engineered plants were protected against losses.

14.5  synthesis of the storage proyeins occurs at the rough endoplasmic reticulum

seed storage proteins are formed by ribosomes at the rough endoplasmic reticulum (er) (fig.14.1). the newly synthesized proteins occur in the lumen of the er, and the storage proteins are finally deposited in the protein bodies. in the case of 2s-proteins and prolamins, the protein bodies are formed by budding from the er membrane. the globulins are mostly transferred from the er by vesicle transfer via the golgi apparatus (section 1.6). first to the vacuole, from which protein bodies are formed by fragmentation. there also exists a pathway by which certain proteins (e.g.,globulins in wheat endosperm ) are transported directly by vesicle transfer from the er membrane to the vacuole without passing the golgi apparatus.

figure 14.2 shows the formatiom of legumin in detail. the protein formed by the ribosome contains at the n - terminus of the polypeptide chain a hydrophobic section called a signal sequence. after the synthesis of this signal sequence, translation comes to a halt, and the signal sequence forms a complex with three other components:

1- a signal recognition particle,

2-a binding protein located on the er membrane, and

3- a pore protein present in the er membrane.

the formation of this complex results in opening a pore in the er membrane: translation comtinues and the newly formed protein chain (e.g. pre pro legumin ) reaches the lumen of the er and anchors the ribosome on the er membrane for the duration of protein synthesis. immediately after the peptide chain enters the lumen, the signal sequence is removed by a signal peptidase located on the inside of the er membrane. the remaining polypeptide, termed a pro - legumin,contains the future alpha - and beta - chains of the legumin. an s-s linkage within the pro - legumin is formed in the er lumen. three pro - legumin molecules form a trimer, facilitated by chaperones.during this association, a quality control occurs: trimers without the correct conformation are degraded. the trimers are transferred via the golgi apparatus to the vacuoles, where the alpha- and bete - chains are separated by a peptidase. the subunits of the legumins assemble to hexamers and are deposited in this form. the protein bodies the final storage site of the legumins are derived from fragmentation of the vacuole. the carbohydrate chains of glycosylated vicilins (e.g of the phaesonlins from the bean phaseolus vulgaris ) are processed in the golgi apparatus.

the pre-pro-forms of newly synthesized 2s- proteins and prolamins which occur in the lumen of the er also contain a signal sequence. completion and aggregation of these proteins takes place in the lumen of the er from which the protein bodies are formed by budding.

14.6 proteinases mobilize the amino acids deposited in storage proteins

our knowledge about the mobilization of the amino acids from the storage proteins derives primarily from investigations of processes during seed germination. in most cases germination is induced by the uptake of water causing the protein bodies to form a vacuole. the hydrolysis of the storage proteins is catalyzed by proteinases which are in part deposited as inactive pro - forms together with the storage proteins in the protein bodies. other proteinases are synthesized anew and transferred via the lumen of the er and the golgi apparatus to the vacuoles (fig.14.2). these enzymes are synthesized initially as inactive pro - forms. activation of these pro - proteinases proceeds by limited proteolysis, in which a section of the sequence is removed by a specific peptidase. the remainder of the polypeptide represents the active proteinase.

the degradation of the storage proteins is also initiated by limited proteolysis. a specific proyeinase first removes small section of the protein sequence resulting in a change in the conformation of the storage protein. in cereal grains s-s bridges of storage proteins are cleaved by reduced thioredoxin (section 6.6) the unfolded is then susceptible to hydrolysis by various proteinases : for example, exopeptidases, which split off amino acids one after the other from the end protein molecule and endopeptidases which cleave within the molecule. in this way storage proteins are completely degraded in the vacuole and the liberated amino acids are provided as building material to the germinating plant.

further reading

15

glycerolipids are membrane constituents and function as carbon stores

glycerolipids are fatty acid esters of glycerol (fig. 15.1). triacylglycerols ( also called triglycerides ) consist of a glycerol molecule that is esterified with three fattyacids. in contrast to animals in plants triacylglycerols do not serve as an energy store but mainly as a carbon store in seeds and they are used as vegetable oils. in polar glycerolipids the glycerol is esterified with only two fatty acid and ahydrophilic group is linked to the thired -- oh group. these polar lipids are the main constituent of membranes.

14.1 there are three ways of deppsiting storageproteins in proteinbodies. A. in the formation of prolamins in cereal grains the prolamin aggregates in the lumen of the ER and the protein bodies are formed by budding off from the ER membrane. B. the proteins appearing in the lumen of the ER are transferred via the Golgi apparatus to the vacuole. the protein bodies are formed by fragmentation of the vacole. this is probably the most common pathway. C.the protein appearing in the lumen of the er are directly transferred to the vacuole circumventing the golgi apparatus.

figur14.2  legumin synthesis. the pre - form of the legumin ( pre pro legumin )formed by the ribosome is processed first in the lumen of the er and then further in the vacuole to give the end product.

figur 15.1 triacylglycerols containing three fatty acids are of a nonpolar nature. in contrast polar lipids are amphiphilic substances since besides the hydrophobic tail consisting of two fatty acids they contain a hydrophilic head. 

درحالی که محصولات co2جذب شده درگیاهان به صورت پلی ساکاریدoligoتشکیل شده است بطوریکه درفصل 9بحث نمودیم اسیدآمینه هامحصولات جذبی نیترات راکه ذخیره شده اند بطوریکه این نوع پروتین ذخیره ای مخصوص پروتین هاست اغلب فعالیت enzymaticدرسلول مدت ها پروتین ساختاری توسط یک غشاجداقرارداده شده اندوendomembranceازشبکه آندوپلاسمی ودستگاه گلژی یاواکوئل ها مشتق شده اندپروتینهای ذخیره ای درسیب زمینی هم درواکوئل ذخیره شده اندوناشی بشودوریشه های آنهادربذرها ذخیره شده اندوtubersandهم درکامبیوم تنهادرطی زمستان که شکل گیری تندندارنددرجوانه های تخم داروتنه درختان وجوانه هاامکان بدهند درغلات پروتینهای ذخیره ای،دراندوسپرم واقع شده اندوبذوردرلپه هاکه بیشترازنیام بذرمیدهد درحالی که غلات مقدارپروتینش به 10%تا15%ازوزن خشک ودرمقداری بقولات آن به بالای 40-50ودرحدود85%ازاین پروتین هستند

پروتین های ذخیره ای اساس تغذیه انسان است:به هرحال درپروتینهای ذخیره ای گیاهان محتوی اسیدآمینه های ضروری خاص برای تغذیه انسانها هستندکه درحیوانات کمتراست درغلات برای مثال پروتین ذخیره ای تریپتوفان میباشدبنابراین درانسانهایی که کاملاگیاه خوارهستندکمبوداسیدآمینه که موجب خسارت ذهنی وفیزیکی به خصوص دربچه هامنجرشودکمتردارنداین مسئله درخوک وخوراک طیورهم میتواندباشددرمهندسان ژنتیک گیاهی دریک پژوهش به منظوربهترشدن نسبت اسیدآمینه وپروتینهای ذخیرهای درمحصولات خرمن توسط دانشمندان علاقه منددرپروتین گیاهی بوسیله دانشمندان ایتالیایی درسال1745صورت گرفتکه قبلاپروتین راازگندم جداکرده بودند

در1924درایستگاه تجربیb.t  زمانیکه که ساختمان این پروتین هاتعیین شدمشخص شدگلوتلینهاوپرولامینهاازنظرساختاری نزدیک به هم هستندولی نه مثل هم که تصورگذشته رامبنی برپرولامین هاازهمان گلوتلینهاهستندبرهم زد.دراین زمان تعدادی نمونه برای پروتینهای  ذخیره ای گیاهی درطبیعت پیدانمودند.

14.1گلوبولینهافراوانترین نوع پروتین ذخیره ای:

درعمل درتمام گیاهان مقدارهای متفاوتی وجوددارد.مهمترین گلوبولینهابه گروه لگوم هاتعلق دارندکه این گلوبولینهابصورت رمزی شده توسط خانواده آمولتی ژن هاکه سبب تولیدتیره های مشترک ازیک پایه میباشد.لگومین فرم پروتین های ذخیره ای بذرهای بن شنی میباشد.برای موردباقالادرصداین پروتین به 75%متشکل ازپروتین ذخیره ای لگومین میباشد.لگومین یک هگزامرباجرم مولکولی بین300-400 kda میباشدمونومرهاشامل دوزنجیره پپتیدی که توسطیک رشته پلی (α-β)ی دی سولفیدبه هم وصل شده اندکه قسمت آلفابزرگ وجرم مولکولی آن درحدود35-40kdaوبتاکوچک باجرم مولکولی درحدود20kdaداردهگزامرهاازبه هم پیوستن گروهای (α-β)مونومرهابه هم ساخته می شونددرهگزامرهامولکولهای پروتین طوری چیده شدندکهaveryبسته عادیتدارک دیده شدندکه میتواننددراین فرم به پروتین ساختاری تبدیل شوند.مولکولهای پروتین که درزنجیره های پروتین هستندتاشده به طورصحیح به سوی این بسته به طورمتناسب حرکت مینمایدوتوسطپپتیدازها تنزل داده میشوند.اگرچه امروزه تغییرمحل اسیدآمینه هادریک پروتین نسبتابوسیله مهندسی ژنتیک آسان به نظرمیرسدامااین فرایندی بسیارپیچیده وسه بعدی میباشد.پیشرفت های اخیردربدست آوردن بلورها وآنالیزساختارآنهاتولیدپروتین های سه بعدی پیش ماده را بخوبی ازپروتین های ساختاری بالغ امکان‌ساختند.این مطالعات آشکارکردپایداری پروتین های ساختاری‌وآنزیم های تجزیه کننده انها درواکوئلها هستندامااین پروتین های ذخیره ای بنابرحقیقت علیه تجزیه موادپروتینی محافظت شده هستند.

نمایش همانندسازی vicillinدردنباله اسیدآمینه اش درلگومین نشان میدهدکه مونومرهاعمدتامرتب ترندوناتوان دراستفاده ازپل پیوندیs-s .اغلب درلگومهاتضادنیزدرglycosylated vicillinsوجودداردآنهاباقیمانده ماده قندی مثل مانوز وگلوکزوn-استیل گلوکوزامین دربردارند

پرولامینهاتنهادرگندمیان مرتعی مثل غلات هستند.آنهابه عنوان آمیخته چندشکلی گونه های متفاوت زیادی داراهستندبرخی ازاین هاتوسطsubunits  s-sbridgeبههم متصل شدند.درگلوتنین هم که درغلاتی مثل گندم وچاودارمونومرهاتوسط پلs-s  به هم متصل شده اند.مولکول گلوتنین دراندازه متفاوت است مناسب بودن اردنانوایی به مقدارومحتواوکیفیت گلوتنین آن وابسته است وآردغلاتی مانندجویولاف وبرنج بدلیل عدم داشتن کافی آن مناسب برای پخت نان نیستند.اززمانیکه گلوتن یک ضریب حساس درتعیین کیفیت غله نان محسوب شده تحقیق های زیادی برای بهبودکیفیت گلوتنین محتوی درغله نان بوسیله مهندسی ژنتیک شده

14.3  پروتینهاs- دربذرهای گیاهان دولپه ای حضوردارند:

s-پروتینهاهم کاملاازپروتینهای ساختاری هستندآنهایک گروه نامتجانس پروتینهارانشان میدهندکه تعریف منحصربفرددارندکه ضریب رسوب گذاریشان درحدود2است.تحقیق هاازساختارشان آشکارکرده است که بیشتر25-پروتین ازیک ساختاربه هم مرطبت ساخته شده واحتمالابه همراهپرولامینهاازیک پروتین مادرمشتق شده اند.napinشکل یک پروتین ساختاری برجسته درشلغم روغنی است که مثالی ازیک25-پروتین هاست که بعدازاینکه روغن ازآن استخراج شده باقیمانده آن بعنوان علوفه به کاربرده‌شده است.اماتوجه داشته باشیم

14.4   پروتینهای مخصوص بذرازخورده شدن آنهابوسیله حیوانات حفاظت میکند:

پروتینهای ساختاری تعدادی ازبذرهاوپروتین های‌دیگراگرچه هم موقت باشندبذرراازخورده شدن محافظت میکنند.برای مثال:

1.          پروتین ساختاری ویلین یک کارکرددفاعی داردبوسیله بستن به بسترکشت باکیتین قارچ هاوحشره ها 

2.          درتعدادی حشره آن باتوسعه لاروپشه مداخله میکند 

3.          بذرتعدادی ازبقولات که به باقیمانده های شکربدون توجه به سفت شدن آزادوموادمتشکله گلیکولیپیدهایاگلیکوپروتین هاهست 

4.          این بذرهاتوسط حیوانات مصرف شده‌ولکتین آنهابه گلیکوپروتین درروده تبدیل شده بدین گونه‌باجذب غذامداخله میکننددرواقع بذرتعدادی ازبقولات وانواع دیگرهم پروتینهایی که مانع ازگوارش‌دردستگاه حیوانات‌دارند. 

5.          لوبیاهابه خاطرمانع شونده های که درمحتوای لکتینشان وپروتین خوددارندتنهابعدازتجزیه وتخریب‌آنهاتوسط حرارت دهی برای مصرف انسان مناسب میشوند 

6.          امااینکه انسانها چطوربه پختن آن روی آوردندبه دلیل داشتن کرچک فوق العاده پروتینی سمی ریسین درآن میباشدکه چندمیلی گرم آن میتواندیک انسان رابکشد. 

7.          لوبیاها هم مانع شونده های‌آمیلازدارندکه مخصوص آبکافت نشاسته بوسیله آمیلازهادردستگاه گوارش‌حشره های خاص جلوگیری میکند.مهندسان ژنتیک‌ازاین مانع شوندهای‌(alpha-amylase) استفاده نموده ودربذرهای نخودفرنگی‌ازآن استفاده نموده 

لاروپشه وسوسک درانبارکردن نخودفرنگی مشکل سازبودندکه باکمک مهندسی ژنتیک این مشکل حل شده است وارقام مقاوم علیه خسارت تولیدشده است.

14.5  سنتزپروتینهای ذخیره ای درشبکه آندوپلاسمی دانه هابه فرم پروتین ذخیره ای توسط ریبوزمهادرشبکه آندوپلاسمی زبر:

بتازگی باسنتزوترکیب نوعی پروتین باپروتینهای ذخیره ای درروزنه وپروتینهای ساختاری ودرموردپرولامینها و2s-پروتینها پروتینهای ساختاری هستندبه فرمbudding from the membranceگلوبولینهاعمدتاازERتوسطحفره دستگاه گلژی (قسمت1.6)انتقال داده شده به واکوئل کهابتدابدنه پروتین توسط تجزیه تشکیل شده است .یک راه هم بوسیله پروتینهای خاص (مثال گلوبولینهادرآندوسپرم‌گندم)که مستقیما توسط انتقال از حفره یERغشابه واکوئل بدون گذرازدستگاه گلژی حمل شده است.

درواقع عکس عمل فرمیشن درلگوماهابصورت جزئی نشان میدهد.پروتین بافرم ریبوزمی تشکیل ترمینالی اززنجیره پلی پپتیدبایک قسمت بایک برش آبگریزکه یک دنباله برجسته میسازد.بعدازسنتزاین دنباله بابرگشت به یک توقف میرسدودنباله برجسته یک اجتماع باسه مولفه ی دیگرتشکیل میدهد.

o           باشکل برگشتی پروتین بتازگی تاسیس کرد 

o           باقیمانده پلی پپتیدهاشاملtermedبشکل موافق درلگوم ها 

o           زنجیره های بتا درلگوم‌هاکه یکs-sلینکاژدرداخل ERتشکیل شده است. 

o           همچنین سه مولکول ویراشگرتشکیل شده که این کاراتسهیل میکند 

o           دراینجایک انجمن کنترل کیفیت تاسیس شدکه توجه آنهابه کیفیت موادبوده که شاهداین هستندکه ازطریق دستگاه گلژی به واکوئلهاجاییکه آلفا-بتاانتقال داده شدهاندزنجیرهاتوسط یک پپتیدازجداشده اند. 

o           SUUNITSهادرلگومهابه شکل هگزامرتجمع یافته ودراین فرم باقی میمانند. 

پروتین های ذخیره ای درلگوم هاازتجزیه واکوئل ومشتقات آن حاصل شده اند.زنجیره های موادقندی ویسیلین گلیکوسیلات‌(مثلادرلوبیا)دردستگاه گلژی پیشرفته وپیچیده هستندکه به تازگی 2S-PROTEINوپرولامینهاراتوانستندترکیب کنندکه درروزنهERهم یک دنباله برجسته داشته داشته باشدتکامل دراین پروتینهادرروزنه ERرخ میدهدکه پروتین ساختاری‌توسط جوانه زنی تشکیل میشود.

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14.6  رسوب آمینواسیدهاباعت تجمع پروتین ها وتولیدپروتئن ساختاری:

دانش ماراجع به تجهیزاسیدآمینه هاازپروتین های‌ذخیره ای دردرجه اول ازتحقیق برروی جوانه های تخمهانشات میگیرد.جوانه زدن دراغلب مواردتوسط جذب آب،موجب شده پروتین های ساختاری ترغیب شده‌که یک واکوئل تشکیل بدهندآبکافت پروتینهای ذخیره ای‌وکاتالیزرهابوسیله پروتیناز هااست بصورتیکه غیرفعال میمانندووبایکدیگرباپروتین های ذخیره ای‌،پروتین ساختاری تشکیل میدهند.وپروتینازدوباره‌ازطریق روزنهERودستگاه گلژی به واکوئل منتقل شده‌تادوباره ترکیب شوند(قسمت14.2)درآغازاین آنزیم هاکمپلکس‌نافعال تشکیل میدهندسپس فعال سازی پروتئینازبوسیله تجزیه موادپروتینی به شکل محدودوکندپیش میرودتایک برش ازدنباله توسط یک قسمت خاص پپتیدازبرداشته شود.باقیمانده پلی پپتیدفعال راپروتئینازنشان میدهد.سیرقهقرایی پروتینهای‌ ذخیره ای‌هم توسطتجزیه موادپروتینی‌محدودشروع می شود.ابتدابرش کوچکی ازنتیجه دنباله پروتین درقالب پروتین ذخیره ای‌برداشته ودرغلات پروتینهای ذخیره ایS-Sپلی میزنندشکاف برداشته وکاهش یافته‌بازشده ودرلحظه حساس خودوآبکافت بوسیله پروتینازمیشودبرای مثال:اگزوپپتیدازهاکه ازاسیدهای آمینه غیرفعال استبعدازآخرین پروتین آمده واندوپپتیدهارادرداخل مولکول ایجادمیکندازمولکولهای دیکردراین فرآینداینست که پروتینهای ذخیره ای درواکوئل کاملاتنزل داده شده‌واسیآمینه های آزاردشده‌بعنوان موادساختمانی درگیاه‌درحال رشدبکارمیرود.

15 . گلیسیرولیپیدهاموادمتشکله غشاوعملکردذخیره کربن:

گلیسیرولیپیدهااسترهای اسیدهای‌چرب گلیسیرین هستند.تری گلیسیریدشامل یک مولکول گلیسیرن با سه اسید چرب‌است‌برخلاف حیوانات که یک منبع انرژی استدرگیاهان تری گلیسیریدبیشتربه عنوان ذخیره کردن دربذرهاعمل میکندکه دارای روغن نباتی میشوندکه اینگونه بهتراست گلیسیرولیپیدقطبی شامل گلیسیرین ودواسیدچرب میباشدکه این چربی بیشتردرعبورموادازغشاعمل میکنند