eChapters

Genus : Litchi 
Species : chinensis  Sonn.
Family : Sapindaceae
(Sub family-Nepheleae)
Chromosome No. : 2n=30

A Chinese renowned statesman Chang Chow-ling of the eighth century in a poem on litchi indicated it as the most luscious of all fruits, and in quality surpasses the other two southern China’s famous fruits i.e. orange and peach. Litchi cultivation has been restricted to few selected sites mainly for its somewhat exacting in its climatic and cultural requirements. In recent times as litchi has established in the tropical America, there appears no doubt that very soon the fruits shall be in abundance in different parts of the tropics and subtropics. The most limiting factor in early dissemination of litchi was the perishable nature of seed and prior to steam navigation it was very difficult to transport the seeds from one continent to another successfully.

Genus : Nephelium 
Species : lappaceum L.
Family : Sapindaceae
Chromosome No. : 2n = 22

Rambutan is one fruit from the Malay Archipelago which has become very popular in its place of origin and is well distributed here. Besides, rambutan a number of other valuable tropical fruits are present which are yet to be cultivated extensively in other tropical and subtropical parts of the world. In Singapore and Penang the fruit grows in abundance. Though very popular in Malay Archipelago, Sri Lanka, however it is unknown in India, Madagascar, Mauritius etc. The fruits common name has been derived from Malayan word rambut referring to hairs by which the fruit surface is covered with. The fruit is also known by other names like Rambustan, rambotang, ramboetan etc. The crop is strictly tropical in climate requirements and is very sensitive to frost. For best performance it likes a hot and moist climate and is a major factor why the crop has not succeeded in most other places.

Genus : Euphoria/Nephelium/Dimocarpus
Species : longana (Lour.) Stend. cinerea
Family : Sapindaceae
Chromosome No. : 2n = 20

The longan (Euphoria longana) belongs to the Sapindaceae or soapberry family to which more important fruits like litchi and rambutan also belongs. The family contains more than 1000 spp. from 125 genera widely distributed in the tropical and warm subtropics. Most of the species are native to Asia though some are also found in south America, Africa and Australia. The genus has seven species but only longana is both horticulturally and commercially important as it yields/produces edible fruits. For most of the growth, flowering and fruit characters it is similar to the two above horticultural crops mentioned. In respect of soil and climate it is less demanding and does adapt or tolerates drier and cooler condition better than litchi.

Genus : Ficus 
Species : carica L.
Family : Moraceae
Chromosome No. : 2n = 26

Fig along with fruits like date palm, grape (vinifera) and olive was regarded as an important food crop of the ancient civilization that developed in the Mediterranean region. The fig description occurred prominently in number of songs as well as in the mythological and historical events that took place at that time. Fig is thought to be native of southern parts of Arabian peninsula, Italy, Balkan and USSR region. Fig was in cultivation as early as 300 BC and from Arabian peninsula it spread to Turkey, Syria, Iraq and later to many subtropical parts of the western hemisphere.

Genus : Artocarpus 
Species : heterophyllus L. (Lamk.)
Family : Moraceae
Chromosome No. : 2n = 56

Afamous traveller John de Marignolli has described jackfruit as ‘there is again another wonderful tree, which produced fruit on the trunk, and was very pleasing to see and the fruit was as big as a lamb‘. The rind is hard and has to be cut open by a sharp knife, the pulp inside is of pleasant flavour sweetness of which matches the honey and usually contains 500 or more chestnut like seeds which are eaten after roasting. In its place of origin (India) where it has been grown since ancient times it is held in great esteem. Theopharatus and Pliny who wrote about jackfruit also expressed similar opinion about the fruit. In India several vernacular names are given like Kanthal, Kathal, Panasa and Kantaka.

Genus : Morus 
Species : alba, nigra, rubra L.
Chromosome No. : 2n=28  
2n=42  2n=28 (56, 84)

Plants are ornamental and fruit bearing trees have wide adaptability. Plant loves to grow on garden soils but also grow or rocky and marginal soils. The number of species is disputable but two species are native of North America. Mulberries are usually cultivated as food or for rearing of silkworms and for the edible fruits. The silkworm mulberry is M. alba and fruit bearing mulberry is M. rubra. In India and elsewhere mulberry is known primarily as a fruit bearing tree, although it is not yet planted extensively, though few trees around home ground are common. Mulberry is remarkable for its foliage and for variable forms. The extent of variability is so pronounced that several forms may be present of a single tree and different trees of the same species show distinct individual

Genus : Diospyros 
Species : kaki L.
Family : Ebenaceae 
Chromosome No. : 2n=60, 90

Persimmon-Kaki, though native of China, but it was in Japan where the fruit developed to its present status and much of the cultural practices were established or developed in Japan, hence the Japanese name by which it was popular in Japan was accepted all over the world. Japanese persimmon sometimes called as date plum and Chinese date-plum are the names generally used to describe persimmon in United States. The Chinese name is Shitz and in France it is called as plaquemine. In Japan Kaki is regarded to be their prime and best fruit and about 800 cultivars have been recorded and described. Likewise the Chinese also fancy persimmon and large areas have been put under its cultivation.

Genus : Diospyros 
Species : kaki L.
Family : Ebenaceae 
Chromosome No. : 2n=60, 90

Persimmon-Kaki, though native of China, but it was in Japan where the fruit developed to its present status and much of the cultural practices were established or developed in Japan, hence the Japanese name by which it was popular in Japan was accepted all over the world. Japanese persimmon sometimes called as date plum and Chinese date-plum are the names generally used to describe persimmon in United States. The Chinese name is Shitz and in France it is called as plaquemine. In Japan Kaki is regarded to be their prime and best fruit and about 800 cultivars have been recorded and described. Likewise the Chinese also fancy persimmon and large areas have been put under its cultivation.

Genus : Persea 
Species : americana Mill.
Family : Lauraceae
Chromosome No. : 2n =24

Horticulturally avocado (Persea americana) is a new fruit and is often considered to be  one of the most   nutritive of present day fruit crops. Genus Persea, name has been derived from ancient Greek name of an Egyptian tree with sweet fruits  derived probably from Perseus. Avocado belongs to the family Lauraceae, has 47 genera and about 1900 species. Genus Persea has some 150 species of tropical evergreen trees. Its discovery in the new world has contributed much to the human diet. Fruit is a rich source of fat (27%), 2 per cent protein content is higher than in any other fresh fruit, mineral like Ca, Cl, Fe, Mg, P, K, Na and sulphur are also higher that makes avocado as a useful food which produces more of base forming elements rather than acid forming elements that are found more only in nut crops.

Genus : Achras /Manilkara
Species : sapota L. zapota (Mill.) Forberg 
Family : Sapotaceae
Chromosome No. : 2n=26

Thomas Firmingaer, an English horticulturist while in India in praise of sapota wrote ‘a more luscious, cool and agreeable fruit is not to be within this or perhaps any other country in the world’. A French botanist described sapota as ‘the sweet perfumes of honey, jasmine and lily of the valley’. In view of these the fruit is considered to be one of the best fruits of tropical America, although cannot be compared with the other more popular fruits of the region i.e. pineapple and cherimoya. In many tropical parts of the world this delicious fruit is held in high esteem.

Genus : Zizyphus /Rhamus
Species : mauritiana Lam. jujube Lam.
Family : Rhamnaceae
Chromosome No. : 2n = 24, 48, 96

According to famous writer David Fairchild it is the jujube, the large fruited Chinese type which is at its best compared to the inferior type which are in abundance in Arabia, northern India and southern Europe. The resultant inferior fruits are either from a different species compared to those of China or from varieties which have not been much influenced and improved by selection and cultivation.

Genus : Punica 
Species : granatum L.
Family : Punicaceae
Chromosome No. : 2n = 16,18

Pomegranate has originated in Afghanistan and Iran the abode of prophet Mohammad and for very long has been associated with grape and fig and is still held in higher esteem. Acknowledging the multi usefulness of pomegranate Prophet Mohammad said ‘Eat the pomegranate sententiously for it progress the system of envy and hatred’. The crop was very much in demand and liked by the inhabitants prior to the days of Mohammad in the Orient, as pomegranate has something special in the form of refreshing which the people of hot arid region like and adore enormously. The ancient Semitic name rimmon was adopted by Arabs as rumman. The Potruguese roma or roman was formed from rumman. The present botanical name Punica granatum has been derived from Roman name malum punicum (apple of Carthage) and granatum.

Genus : Passiflora 
Species : edulis Sims.
Family : Passifloraceae
Chromosome No. : 2n = 18

The passion fruit (Passiflora edulis) is another fascinating tropical fruit besides having both dessert and processing qualities, the crop also has a big multi coloured very attractive flower and fruit with district taste  and flavour. Passion fruit is very popular in number of tropical and subtropical countries. Despite having variability at the species level the commercial development has not progressed as desired which is evident from the fact that the available commercial types are highly susceptible to diseases, lack of adaptation to soil and climate extremes, high establishment costs growing management problems  harvesting and market costs have forced the grower to focus on other remunerative crops. Passion fruit is said to be good source of minerals especially calcium, phosphorus and iron, vitamin A, niacin and riboflavin.

Genus : Eriobotrya 
Species : japonica Thunb./Lindl.
Family : Rosaceae 
Chromosome No. : 2n = 34

In Orient this beautiful and excellent fruit has failed to acquire the commercial significance which the crop deserves, further no concerted efforts have been made to improve it through selection and cultivation as has been done for many other Asiatic fruits. In contrast to major tropical and subtropical fruits which are said to be too sweet, loquat is one fruit that has subacid, sprightly flavoured fruits that match in taste and flavour to those of temperate fruits. The loquat has been in cultivation since antiquity in Japan and under present fruit culture scenario is one of the important fruits of that country

Genus : Durio 
Species : zibethinus Murray.
Family : Bombacaceae
Chromosome No. : 2n= 56

The exact place to which durian is indigenous is not established with certainity. The specie is said to be native to Borneo and other adjoining islands of Malay Archipelago. The species is seen growing in Sri Lanka and some other tropical countries. Outside the Malayan region durian cultivation is greatly restricted and is usually confined to the botanic gardens from study point of view. The crop has failed to move away from its native place primarily due to the fact that seeds are highly perishable which has restricted durian movement within tropical places of the world. Further due to the disagreeable flavour this fruit has not met with the favour from the Europeans. The banks of the Sarawak River are covered with many fruit trees that basically fulfill the food requirements of the local inhabitants called as Dyaks. Of the different kinds of fruit tree, durian is the most important found in abundance and is rated very highly.

Genus : Grewia
Species : subinequalis DC., asiatica L.
Family : Tiliaceae 
Chromosome No. : 2n = 36

Phalsa (Grewia asiatica) belongs  to the family Tilaceae and some members  are native of India too and is  mentioned in Vedic writings and various plant parts are employed to cure number of ailments. The family comprises  of 18 genera and some 400 species distributed mostly in the tropical and subtropical areas of the world. Of the prevailing 140 species,  40 are indigenous to India of which Grewia asiatica is of significance horticulturally. Phalsa is commercially  cultivated in Uttar Pradesh, Punjab, Haryana, Rajasthan, Madhya Pradesh and on limited scale in Bihar, West Bengal, Gujarat, Maharashtra and Andhra Pradesh.

Genus : Garcinia
Species : mangostana L.
Family : Guttiferae
Chromosome No. : 2n = 56-76, 88-96, 120-130

In family Guttiferae to which mangosteen belongs, very few plants are fruits and yield drugs, gums and resins. It is a tropical fruit and occupies an important place in Garcinia family. The European voyagers on their return indicated wonderful stories of the East and mention of mangosteen received huge praise. Hacobus Bontius termed the fruit as ‘Queen of fruits’ the finest fruit in the world. Because of beautiful colouring of fruit alongwith pleasant delicate flavour makes mangosteen the most esteemed fruit of Asiatic tropics and no other tropical fruit equals to that of mangosteen. Despite being designated as the finest fruit of the tropics, the fruit is mainly confined to the limits of East Indies. The species is found wild in the forests of Sunda Islands and of the Malay peninsula. Writers have indicated that mangosteen is usual dooryard tree in the East Indies, more in Java and Sumatra. Some small orchards of mangosteen have come up in Sri Lanka, but they are most abundant only in Malay Archipelago.

Genus : Averrhoa 
Species : carambola L.
Family : Oxalidaceae
Chromosome No. : 2n= 22, 24

According to a Dutch traveller Linschoten (1598) has described carambola as a ‘fruit with eight distinct corners as big as a small apple, sour in taste, resembles an unripe plum. The Chinese and Hindus eat this fruit as vegetable when green and as a fruit (dessert) when ripe. Carambola is esteemed in the Orient and is wide spread in the tropics. The bilimbi is a close relative to Carambola and in every livelihood is native of Malayan region and is considered as the only cultivated species. The fruit is very acidic in taste, and in appearance resemble cucumber.

Genus : Aegle 
Species : marmelos (L) Correa
Family : Rutaceae
Chromosome No. : 2n = 18(36)

Bael (Aegle marmelos Correa) besides being indigenous to N. India it is also one of the most useful medicinal plant of India, as it has number of curative properties. In Ayurveda the Indian medicine system use of unripe fruit is advised for acute dysentery and diarrhoea whereas ripe fruit acts as an effective laxative. Amongst the fruits native of India, bael is said to be the most nutritious fruit, is rich in protein minerals, carbohydrates, vitamin C as well as in riboflavin content. Despite these quality statistics the fruit failed to become popular (as dessert) primarily it being very seedy with thick hard shell and mucilaginous flesh but the processing qualities needs to be exploited judiciously.

Genus : Carissa
Species : grandiflora A.D.C. carandas L.
Family : Apocynaceae
Chromosome No. : 2n=22

The carissa (Carissa grandiflora) is regarded not only for its ornamental value but also for its edible fruits. The plant is not very demanding in its climatic requirements. It grows successfully in the warm moist tropical regions and also in the dry subtropics where the temperature never falls below 26-28oC. In United States, especially in California, Carissa is injured by frost, whereas in Florida frost has no influence on the crop. This crop species is valued highly as a hedge plant, as it resists severe pruning and resultant growth is usually low and compact, which are desired traits for hedge plant. The thorny, stout branches make an impenetrable barrier for animals.

Genus : Cyphomendra 
Species : betacea  (Cav.)  Sendtner
Family : Solanaceae
Chromosome No. : 2n = 24

The tree tomato is a bushy fruit plant which in early time was planted in the gardens high upon the mountain slopes. Presently in India, Sri Lanka and number of other countries it is grown in the hilly region. Indians of Peru at very early stages gave the world a number of food plants of which potato is of great value, and tree tomato in the only woody species of family Solanaceae. The tree is fast growing and starts to bear in about two to three years times. The egg shaped and usually smooth-skinned fruits are produced in large number in hanging clusters. The sub acidic and succulent fruits are agreeable and eaten as raw. In central America it is called tomate and cultivated at an elevation of 4000 to 8000 feet. The crop loves rich loamy soil and grows best under irrigated conditions.

Genus : Physalis 
Species : peruviana L.
Family : Solanaceae
Chromosome No. : 2n = 28, 48

Physalis (Greek for Bladder, as the thin calyx enlarges and encloses the fruit). Fruit is called as husk tomato or ground cherry. Is  a plant of warm and temperate  regions and is mostly cultivated for its edible fruit  which is sub acidic in taste and  the flavour resembles that of tomato hence the name tree tomato or husk tomato. The genus comprises  nearly 75 species mostly of American origin, however few species are also found in Asia and Europe. The species peruviana and pubescens are cultivated for their edible fruit whereas P. alkekengi Linn and  P Franchetii  Hort., are highly valued for their shiny large red calices. Plant is a very old garden plant grown mainly for its brilliantly coloured calices, is perennial, grows zigzag with soft pubescence  on stems. Leaves ovate, base broad and angular, petiole spreading at top. Flowers whitish with yellow anthers.

Genus : Phyllanthus
Species : emblica L.
Family : Euphorbiaceae
Chromosome No. : 2n = 28

The aonla (Emblica officinalis syn. Phyllanthus emblica) is native of tropical south-eastern Asia, and to central and southern India in particular. Aonla although considered as a minor fruit, but is of commercial significance primarily due to early high returns without much care. The small lateral branches resembles pinnate leaves of walnut or sumac and when fall off leaves behind a big scar. Flowers are axillary, apetalous mono or dioecious in small clusters or singly. Plants show great adaptability, are hardy and high bearer. The genus Phyllanthus (Greek-for leaf flower) has some 500 species or even more and two have been identified as important from fruit point of view i.e. P. emblica and P. acidus.

Genus : Malpighia 
Species : punicifolia L., glabra Millsp.
Family : Malpighiaceae
Chromosome No. : 2n = 28

The barbados cherry, a member of the Malpighiaceae, is an interesting example of a fruit that rose like Cinderella, from relative obscurity about 40 years ago. It was at that time the subject of much taxonomic confusion, having been described and discussed previously under the binomical Malpighia glabra L. which properly belongs to a wild relative inhibiting the west Indies, tropical America and the lowlands of Mexico to southern Texas, and having smaller pointed leaves, smaller flowers in peduncled umbels, styles nearly equal, and smaller fruits. M. punicifolia

Genus : Asimina 
Species : triloba (L.) Dunal
Family : Annonaceae
Chromosome No. : 2n = 18

Uses

The delicious pawpaw fruits are used as dessert. The red or brown streak wood is light in weight hence not used for furniture or allied work. On account of its handsome foliage, large leaves and attractive form, it provides additional attraction when planted in gardens.

Genus : Vitis 
Species : vinifera L.
Family : Vitaceae
Chromosome No. : 2n=38, 40

Grapes are considered to be the oldest plants on earth which dates back to 90-95 million years, a time when dinosaurs ruled this planet, hence grape is as old as mankind. Grape is one of the most ancient crops. The Aryans knew grape cultivation as well as to prepare beverages from it. Grape cultivation in India dates back to 11th century BC. Later Muslim invaders from Iran and Afghanistan in the 12th century also introduced grapes to India, further in the 16th century Emperor Akbar the Great introduced and encouraged grape cultivation in various parts of India.

Genus : Actinidia 
Species : deliciosa (Plonch)
Family : Actinidiaceae
Chromosome No. : 2n = 58, 170, 174

The remarkable fruit of the previous century Kiwifruit is known by various names like China’s miracle fruit, the wonder fruit of New Zealand, Kiwi berry, Chinese gooseberry, Yangtao, Grosella and Mihoutao. In a short period of about two decades the crop has attracted huge inclination towards its cultivation and has become an established fruit crop of different world markets, which is unparallel in history of commercial fruit culture. In China the fruit has been growing over centuries in its wild form. The name Mihoutao was used for this crop by the Tang dynasty which indicated peach of the Macaque monkey indicating both the presence of fruit in wild stands and the love of the local monkey for this fruit.

Genus : Fragaria
Species : ananassa Duch.
Family : Rosaceae 
Chromosome No. : 2n=14, 25, 42, 56

Strawberry is relatively small genus comprising of usually low perennial creeping herbs, wild forms found wide spread in temperate and subtropical parts of the world. Cultivated strawberry is highly polymorphic and wide range of diversity present in the wild germplasm has resulted in the development of present day strawberry. Today it is grown throughout the world and is rated high in the list of liked foods. The breeders have contributed enormously towards the development of cultivars with wide adaptability and through the incorporation of desired traits helped to improve its quality dramatically over its wild forms. Today strawberry is known for its distinct delicate flavour, attractive fruit shape and colour and has made a special niche in the soft fruits culture. The cultivated strawberry Fragaria x ananassa Duch has resulted from the crossing of two local America species F. chiloensis (L) Duch. and F.virgianana, Duch.

Genus   : Ribes 
Species : nigrum L. americana Mill.
                bracteosum Dougl. niveum 
                Lindl. divaricatum Dougl.
Family : Saxifragaceae / Grossulariaceae
Chromosome No. : 2n = 16

The genus Ribes belongs to the family Saxifragaceae mainly comprises of woody shrubs distinctly marked with spines and prickles and those which have attractive handsome foliage, flowers and fruits.  The genus name Ribes is likely to be derived from ribas, the Arabic name for Rheum Ribes. Some are of the view that it is the latinized form of riebs,  an old name of currants in Germany.

Genus   : Rubus
Species : idaelus L. (European Red
                Raspberry) strigorus Michx. 
                (Red Raspberry occidentalis L. 
                (Black Raspberry)
Family : Rosaceae
Chromosome No. : 2n = 14 
                            (variable 28, 42, 56, 84)

The blackberries, raspberries, dewberries, boysenberry are collectively referred to as bramble fruits.  Mostly found in the north hemisphere. They belong to the family Rosaceae and genus Rubus. The family has nearly 250 species besides also has large number of apomictic segregates. Usually shrub, the woody species has biennial canes i.e. in the first year remains vegetative and in the second year it fruits and dies. Leaves variable in form from simple leaf to pinnately or palmately compound.  Flowers usually occur in clusters and are variable in colour, white pink to red.  Fruit is an aggregate of number of small drupes.

Genus : Prunus / Amygdalus
Species :  dulcis L. communis, Fritsch.
Family : Rosaceae
Chromosome No. : 2n = 28

Almond tree amongst the deciduous temperate fruits is the first crop to bloom in spring as it responds readily to warm temperature and also for its relatively low chilling requirements. The almond is thought to be one of the oldest nut crop used by man since very long.  However, its specific climatic requirements have greatly restricted its commercial production to limited regions of the world.  The almond blossoms are large attractive pink coloured very sensitive to spring frost, but at the same time the nut require high heat quantum at maturity, cool rainy weather during flowering restricts cross pollination and induces fungal infections. In the mild winter regions almond trees are limited by the fact that distinct chilling requirement for growth and flowering are not met with.

Genus : Juglans 
Species : regia L.
Family : Juglandaceae
Chromosome No. : 2n=2x=32

Walnut (Juglans regia L.) among the nut crops is regarded to be a rich source of proteins, fats and minerals and is said to be a concentrated source of energy. It is on this account that wild walnuts have been utilized as food for human and animals since pre-historic times. It contains good amount of different vitamins of B group and is richest in vitamin B6 compared to almond, pecan, filbert, chestnut and Brazil nut. After the last ice age, records indicate that walnut spread from Asia Minor to other parts of the world, while some opinion it to be even older than man as revealed by fossil studies.

Genus : Carya
Species : illinoensis (Wangenh) K. Koch.
Family : Juglandaceae
Chromosome No. : 2n = 32

Unlike other temperate nut fruits which have been in cultivation for long history of pecan cultivation is just about one hundred years, and in this short period pecan nut has gained huge popularity on account of its sweet nutty flavour and superb tree characteristics that is symmetrical form, luxuriant dark green shinny foliage with added ornamental value. Pecan nut is a remarkable highly valuable gift of North America to the horticulture of the world, and presently occupies fifth position among the leading nut fruit crops. In United States of America, pecan is recognized as ‘Queen of Nuts’

Genus : Castanea 
Species : avellana
Family : Fagaceae
Chromosome No. : 2n = 24

Before the history was started to be written chestnut nuts in Japan and China were harvested, collected and eaten and aptly has been an important food for man around the world especially in Asia, Asia Minor, Europe and North America for hundreds of years. As early as 50 B.C., chestnut was brought to southern Europe by Greeks from Asia Minor and red Indians in North America prior to its discovery. Used nuts of chestnut was a staple food especially during famine times.

Genus Castanea has 13 species and belongs to the family Fagaceae which also has important forest plants like Oak (Quercus), and beech (Fagus). Species of this genus are grown for ornamental and also for their edible nuts. Three species of chestnut are economically important as they produce edible nuts, are highly variable and selection has been practiced for hundreds of years to select high yielding, large fruited type. The species other than C. dentata (American chestnut) are called ‘Chinkapins’.

Genus : Corylus 
Species : avellana L.
Family : Betulaceae
Chromosome No. : 2n=2x=28

European filbert Corylus avellana L, is known by several names common being Cob, cobnut, hazel, Spanish or Lambert nut, which has been due to its origin, fruit shape, husk and the general appearance. ‘Filbert’ has also come from name ‘full beard’ as the nut of commerce is fully enclosed by the long husk. It is this husk or involucres which very often has been used to distinguish between various species and cultivars. Corylus the genus has been derived from korys which indicate bonnet, hood or helmet and there are several other views of its name being derived after the name of some renowned places. The word ‘hazelnut’ is from anglosaxon haesel meaning hood. Further the term hazelnut is used in European and Filbert in Asian countries for and its other species. However in America, the term is used to refer to three native species C. archericana, C. californica and C. cornuta. Filbert is an important member of birch family, Betulaceae which has a long history of cultivation (8000 to 5500 B.C.). 

Genus : Pistachia 
Species : vera L.
Family : Anacardiaceae
Chromosome No. : 2n = 30

Among the nut crops Pistachio nut (Pistacia vera L.) occupies a significant place for its delectable and nutty flavoured kernels which in large quantity is imported to India mainly from Iran and Afghanistan. On account of its demand for very exacting climatic requirements the crop has failed to establish successfully in number of new regions where efforts were made to introduce this crop, despite the fact that it resists drought and adverse soil conditions much better than more important fruits of the family Anacardiaceae. Pistachio trees are long lived but grow very slowly in early years of its plantation compared to many of the deciduous fruit trees. Alternate bearing is also a wide spread phenomena in this crop. Pista is a fruit of temperate region and can withstand wide fluctuation in temperature. The exact place of its origin though not definite, is often regarded to be indigenous to central Asia, where large stands of wild pistachio trees are found growing in abundance.

Genus   : Macadamia
Species : integrifolia Maiden and Betch
Family : Protaceae 
Chromosome No. : 2n =28

Macadamia nut is known as ‘Australian Nut’ or ‘Queensland Nut’ because of its origin in the rainforests of New South Wales and Queensland. The crop is sensitive to frost hence the site which suits orange and lemon tree cultivation is also good for macadamia. Macadamia through cultivated commercially in Australia it is in Hawaii that maximum improvement and advancement in terms of selection of superior cultivars has taken place and in short time of about 100 years macadamia culture has become a very fruitful entrepreneur. Presently there is huge gap between the macadamia nut demand and supply therefore efforts are being made to introduce macadamia into other tropical and subtropical parts of the world.

Genus : Malus  
Species : domestica (Borkh.)
Family : Rosaceae 
Chromosome No. : 2n = 34, 51, 68

Like many other fruit crops, apple too is a very old crop in cultivation. Theophratus as early as third century B.C. has indicated that the Greeks and Romans knew apple culture and among the temperate fruit crops, apple is the most ubiquitous of all fruits and is extensively grown all over the world. Huge genetic variability present has permitted the better adapted types to be selected for plantation under different agro climatic conditions.  Through continuous selection both from wild population and also from hybrid seedlings, varied types or varieties have been selected, some are suitable for cultivation in warm temperate regions and others for extreme cold conditions.  This has resulted/added to the gene pool of desired types of apples enormously. At present cultivars are available destined for specific purposes like dessert, cooking, juice, cider and for large number of other uses.

Genus : Pyrus 
Species : communis L.
Family : Rosaceae 
Chromosome No. : 2n= 34

Pear like apple is also a prehistoric crop and unlike apple its cultivation in Europe started much before that of apple at an early time. According to Homer (1000 B.C.) the ancient Greek said that pears were one of the “gifts of god’s”. Romans also enormously added to the knowledge of pear cultivation. Pliny in Rome had described 35 cultivars (23-79 AD). The variation in fruit characters described earlier match to the range of fruit characters which are found in presently grown commercial cultivars. In Europe for its buttery soft texture and distinct aroma many consider European pear as the most detectable of all temperate fruits, while the Asian pears for their firm crisp texture and juiciness are preferred more in China and Japan – their native place. Pears are readily consumed as fresh, dried, cooked or as preserves or to make perry and pear wine.

Genus : Cydonia / Pyrus
Species : oblonga Mill. vulgaris Pers. 
                cydonia L.
Family : Rosaceae 
Chromosome No. : 2n= 34

The fruit of pome class referred as Cydonia oblonga (also Pyrus cydonia) is an ancient fruit and yet its significance is not fully recognized and crop has received very less attention. There is hardly any mention of this old fruit in respect of its merit, its cultivation or in the form of some standard literature. One reason could be that amongst pome fruits where quince is placed, better fruit form, raw eating quality persisted, which markedly restricted quince improvement. Quince fruit lacks dessert class except when cooked but is commercially used for flavouring, in preparation of jellies marmalade and preserves. However in near East and Persia, quince cultivation is highly improved through the selection of better varieties which are eaten raw.

Genus : Prunus 
Species : persica Batsch
Family : Rosaceae
Chromosome No. : 2n = 16

The peach, Prunus persica (L) Batch is unique among the temperate fruits as it is adaptated to varied climatic conditions and it is for this reason that peach and its close relative the nectarine, in a short period has spread rapidly to different parts of the world. Peach is a tree of temperate zone, but has attained higher quality (fruit colour, taste etc.) in areas where the summer temperatures are relatively warm to hot. With the discovery of low chill types ‘Honey’ and ‘Peen to’ forms from southern China, peach cultivation has been spread to warm temperate regions of the world. Normally peach requires from 500-1000 hours of cold/chill hours below 7.2oC for growth and flowering in the spring. Peach history as a garden crop in China is well documented, and forms varying in flesh colour (white, yellow or red), free stone or cling stone, flower colour, large and showy flower type seen presently were also present at very early time i.e. the beginning of the present century.

Genus : Prunus 
Species : armeniaca L.
Family : Rosaceae
Chromosome No. : 2n = 16

Of all the temperature fruits belonging to tribe pruneae, apricots after cherries are more exacting in their climatic requirements. For this climate specific, apricots are often described as a fruit that fails where other fruits grow successfully. Apricots lavish continental climate, which is characterized by low rainfall (50 cm per year), warm summers and without much variation in winter temperatures and this winter temperature in temperate regions remain close to -33o C. Apricot trees are said to be drought resistant and can sustains low atmospheric humidity but is very sensitive to low soil moisture content.

Genus : Prunus 
Species : domestica institia L. 
                saliciana Lindl.
Family : Rosaceae
Chromosome No. : 2n - 48

Of all the stone fruits, plums are the most varied. They belong to the genus Prunus of the subfamily Prunoideae of the family Rosaceae. All plums have a basic chromosome number of x=8. Plums and related species have been placed in the subgenus Prunophora section Euprunus and Prunocerasus. Six species have been placed in the section Euprunus. Their chromosome number range from diploid to hexploid and are native to the land extending from Europe to China. Thirteen species native to the North American continent are all diploid in nature and have been placed in the sections Prunocerasus. Separation of the plums into the two sections does not appear to have any genetical basis since the species appear to be closely related. Prunus domestica, the European plum, is believed to be the most recent crop species to have arisen within the section Prunophora. Prunus insititia.

Genus   : Prunus
Species : avium cerasus, mahaleb L.
Family : Rosaceae
Chromosome No. : 2n = 16, 24, 32

Records indicate that cherries were in cultivation ever since the beginning of civilization. Cherries exhibit vast genetic variability as is evident from the different species which vary in their ploidy level. Sweet cherries (Prunus avium L) are diploid while sour cherries (P. cerasus, L.) are tetraploid, and commercially more important than the other species. Duke cherry has resulted from hybridization between sour and sweet cherry with intermediate tree and fruit characters. Successful cherry cultivation revolves around climatic factors, prime being the extent and spread of rainfall, variation in day and night temperature, occurrence of frosts, high heat day largely determine the type of cherry that will grow successfully in a particular areas. Hence cherry improvement around the world has so far been localized to few selected areas where different cherries have been successfully grown.

Genus : Olea 
Species : europaea L.
Family : Oleaceae
Chromosome No. : 2n=2x=46

Amongst the fruit crops, Olive is undoubtedly one of the world’s oldest cultivated crop and its cultivations dates back to 3000 B.C. and till date is recognized as a symbol of peace and prosperity. Olive is an evergreen subtropical plant, but for flowering and fruiting it does require chilling as most of the temperate fruits do. Although slow to grow, olive is a very long lived plant and with its typical dense foliage of olive green and silvery leaves also serves as an ornamental type. The centre of origin includes Palestine, Lebanon, north west Syria and Cyprus. The Greeks and Roman were well aware of the significance of olive oil during 900 to 600 B.C. and oil was considered as a luxury item in body anointment. From its native place olive established itself in the Mediterranean region especially Italy, Spain and from here to other parts of the world.

Plant diseases caused by variety of pathogens pose a serious challenge and economic threats to various agricultural crops all around the world. It has been evidenced that despite wide use of chemical pesticides in crop production, the losses due to pests and diseases are significant. Phytonematodes are one of the major groups of organisms that live in diverse habitat and continue to challenge variety of agricultural crops all around the world. Since early times the major agricultural crops have been plagued by these noxious nematodes that feed on various plant parts viz. roots, rhizome, sucker, tubers, seedlings, stem, leaves, buds, crowns and cause damage worth more than 100 billion dollars annually. The major crops severely affected by these pests are, vegetables, fruits, sugarcane, sugar beet, cotton, oil seed, pulses, tobacco, tea, coffee, cereals, spices, medicinal and aromatic plants.

Abstract

The rhizosphere or the zone of influence around roots harbors a multitude of microorganisms that are affected by both abiotic and biotic stresses. Among these are the dominant rhizobacteria that prefer living in close vicinity to the root or on its surface and play a crucial role in soil health and plant growth. Both free-living and symbiotic bacteria are involved in such specific ecological niches and help in plant matter degradation, nutrient mobilization and biocontrol of plant disease. While the rhizosphere as a domain of fierce microbial activity has been studied for over a century, the availability of modern tools in microbial ecology has now permitted the study of microbial communities associated with plant growth and development, in situ localization of important forms, as well as the monitoring of introduced bacteria as they spread in the soil and root environment. Plant-microbe researchers have studied the diversity of rhizobacteria in a variety of plants, cereals, legumes and others along with assessment of their functionality based on the release of enzymes (soil dehydrogenase, phosphatase, nitrogenase, etc.), metabolites (siderophores, antifungals, HCN, etc.), growth promoters (IAA,

Introduction

Soil supports richest number and kinds of microorganisms interacting with each other and thus by modification or alteration in soil conditions greatly influence the microbial community and their activity in soil ecosystem. Soil physico-chemical and the biological factors interact to provide rapidly changing ecological niches and microbial components fluctuate in response to change in soil conditions. There are large evidences that agricultural practices often favour antagonistic microorganisms (Cook and Baker,1983; Yarham,1979) and therefore, biological control of plant pathogens could be possible through manipulation of soil condition. Soil organic matter also has a profound influence on microorganisms in soil, particularly those, including some pathogens, saprophytic and obligate plant parasites. Soil organic matter is distributed at discrete sites within the soil and determines to a great extent which parts of pore space are occupied. 

Introduction

Biological-based crop protection against plant viruses aims to develop sustainable, non-chemical, crop management technologies that utilize natural-occurrants and phytotoxins to control economically important diseases. In this area the efforts were made since the realization that viruses can not be controlled directly unlike other pathogen.

At present in the absence of any direct control of the viruses, strategies so far have been adopted to control them indirectly; like controlling the vectors of viruses (insects, nematodes, fungi etc.), using barrier crops, and use of resistant cultivars. However, success had been very limited. As the biological sciences advanced, many biological systems were utilized to control the diseases in plants caused by viruses, promising among them is using apical-meristem culture techniques to produce virus free plantlets as starting material.

Agriculture is the main source of income of the rural masses in India and the disease accounts for more than 30% losses every year. According to a WHO estimate of 1990. There were 25 million cases of acute occupational pesticides poisoning in developing countries each year. ILO 1996 estimates suggests that out of 14% of all known occupational injuries 10% of all total injuries are caused by pesticides. Further more developing countries are a dustbin for the developed countries. More than 20, 000 tonnes of obsolete pesticides are dumped in Africa alone. The biopesticides are amenable to small scale and local production. Presently there is an increased awareness regarding environmental and food safety. The biopesticides as such can be used as an essential and fundamental component of integrated pest management. It helps to manage the disease which are difficult, otherwise to be managed and so also these control the pests resistant to conventional pesticides. Paulitz and Belanger (2001) has reviewed the potential of biological control in green house systems.