eChapters

India is predominantly an agriculture based country and 65% of the Indians depend on agriculture. To meet the ever increasing nutritional demands of Indian population, production and productivity of vegetables have to be increased manifold within the limited available land and other resources. Seed is the basic and critical input in which the expected dividends from all other inputs depend and it plays a crucial role for enhancing the stability of productivity. With the ever increasing demands for a mechanized, energy efficient type of agriculture, each seed is expected to produce a vigorous plant, which would develop. uniformly under a wide range of environmental conditions.

Seed enhancement technologies have historical basis dating back hundreds to thousands of years. Seed coating was being practiced by ancient Chinese farmers who coated seeds of rice with mud balls to anchor the seeds in water saturated soil . The Greeks presoaked the cucumber seeds in milk or water to make them germinate quicker. Keeping the seeds in moist cloth or soaking in water prior to sowing was a common practice among the farmers of India from time immemorial.

Horticultural crops play an important role in Indian agricultural economy. Though only 2.4% of cultivated area is under these crops, they contribute about 21% to the Agricultural GDP. Though horticultural crops contribute more for the national economy, its contribution could be further increased by minimizing 30% loss of horticultural crops due to pests and diseases. Continuous and unrestricted use have dictated the need for development of ecologically safer pest management technologies. Among the non-chemical methods, resistant varieties, cultural practices, plant derivatives and biocontrol agents are important and these methods can be integrated successfully. In recent years, interest among regulatory authorities, agricultural advisors and growers has forced to seek for alternative solution of plant disease management. It has encouraged intensive research of microbial products as agents for plant disease management. This resulted in commercialization of a number of microbial biocontrol products.

Entomology, a Greek word entomoV, entomos, “ that is cut in pieces or engraved/segmented”, hence “insect”; and -logia, logia -study, is the scientific study of insects , a branch of arthropodology. The arthropods made their appearance during the earliest Devonian period while humans appeared only in Quarternary. Insects possess an immense degree of evolutionary maturity as against man, account for more than two-thirds of all known organisms, date back some 400 million years, and have many kinds of interactions with humans and other forms of life on earth. Entomology is a speciality within the field of biology and it is rooted in all human cultures from prehistoric times.

In India, insects were known from Vedic era and records of insects in India were evident from India’s mythological epics, the Ramayana and Mahabharatha. 

Bioinformatics encompases the use of tools and techniques from three separate disciplines; molecular biology (the source of the data to be analyzed), computer science (supplies the hardware for running analysis and the networks to communicate the results), and the data analysis algorithms, which strictly define bioinformatics. So the list below incorporates events from these areas into a brief history of the field.

Micronutrients play an active role in the plant metabolic processes from cell wall development to respiration, photosynthesis, chlorophyll formation, enzyme activity, hormone synthesis, nitrogen fixation, etc. Micronutrient requirements of crops are relatively small. Use of chemical fertilizers with accompanied changes in soil management practices resulted in steady decrease in micronutrient content in soil. The future of agriculture depends on sustainable management of land, water, flora, fauna and the atmosphere. In order to produce 240 m tones of food grains by the end of twentieth century, removal of major nutrients from soil will be to the tune of 7 m tones N, 2.7 m tones P2O5 and 11.2 m tones K2O. Similarly, a good amount of secondary (Ca, Mg, S) and micronutrients would also be removed proportionately which should be compensated through application of well rotten FYM or micronutrient fertilizers in soil.

Grafting is a horticultural technique. It is used commercially for many woody plants and some herbaceous plants. The purposes of grafting include asexual propagation, obtaining resistance to soil borne diseases, nematodes and unfavorable conditions, and improving fruit quality. Although there are advantages to grafting, graft incompatibility often prevents its practical use. Graft incompatibility occurs when the combination of scion and rootstock is inappropriate. The enormous range of genotype varieties used in grafting results in a wide range of physiological, biochemical and anatomical interactions between graft partners. Therefore, the causes and mechanisms of graft incompatibility vary according to graft combinations. Garner (1979) defined graft incompatibility as the failure to unite into a strong union, the failure to grow in a healthy manner, or premature death, when such failures could be attributed to differences between rootstock and scion.
 
The purpose of this review is to understand graft incompatibility as an aid to solving graft incompatibility problems. The symptoms and types of graft incompatibility are described, the causes and mechanisms of graft incompatibility are explored, and directions for future research are identified.

India produces 9.2% of world’s vegetables and fruits, nearly 109 million tons of vegetables and 57.69 million tons of fruits. The production of horticultural commodities is expected to grow to 300 million tons in near future (Kaur, 2008). India accounts for 18.2% of global trade in vegetables and 0.5% in fruits. The overall food wastages are very high amounting to around Rs. 10.4 lakh million. India wastes more fruits and vegetables than what U.K consumes. It is estimated that cumulative wastage of fruits and vegetables, on the farm, during procurement, storage and at the retail outlets, is worth about Rs.422250 million. 

In general terms, dormancy can be defined as a period during the biological cycle of the plant in which growth of the whole organism (seed) or a plant organ (bud, tuber, corm etc.) is suspended eventhough the environmental conditions for growth may be favourable. More specifically, dormancy refers to a condition in which growth is inhibited by a restriction of essential metabolic processes, such as water uptake, gas exchange and cell division, either as a result of endogenous dormancy-controlling factors or in response to exogenous factors such as changes in the environment. It is distinct from a transient state of quiescence or rest imposed by an unfavourable environment in that dormancy persists even when the environment becomes favourable for growth whereas quiescence ceases.

For wild plants, dormancy has evolved as a means of enabling the plant to endure periods of stress due to drought or low temperatures and is therefore critical for the survival of the species. In cultivated arable or vegetable crops, breeding has generally led to a loss of dormancy or a reduction in the length of the dormant period. In arboreal crops of temperate climates, however, bud dormancy is still an essential feature of the annual growth cycle of the tree.

Reasons for serious concern for food security in developing countries are, increasing food demand for the rapidly growing population, decline in productivity in high productive areas due to ‘Green revolution’ fatigue, and increasing vulnerability of agriculture to potential climate change. Climate scientists predict that global warming will make arable land in many developing countries less productive or unusable. Of all the parameters, abiotic environmental stresses contribute significantly to reduction in potential yield (Flowers and Yeo, 1995). Abiotic stresses arise from extremes of climate. The stress factors especially drought and salinity negatively effect plant growth and development, salt stress being one of the most serious environmental factors limiting productivity of crop plants (Ashraf, 1999). Therefore, extensive research into plant salt tolerance was carried out, with the aim of improving resistance of crop plants. With a large majority of the world’s population relying on crops like barley, maize and rice to survive, crop salt tolerance is globally important.

Very little is known about the basic principles governing the chemistry of flavour or fragrance. In English, the term aroma chemicals is used for both fragrance and flavour compounds. Any compound with a sufficiently high vapour pressure will have an odour and this is normally of the molecular weight of around 300, a relatively low polarity granted (Frater et al., 1998). Generally only compounds with pleasant smell are considered to fall under the realm of fragrance chemistry, but purified individual components from a mixture may have a malodour. Almost all ancient civilizations had their tradition of making fragrances from natural materials, mostly of plant origin, but also of animal origin – these are mostly essential oils, exudates, balsam and resins (Arctander, 1969).
 
It was in the latter half of the 19th century that synthetic fragrance chemicals were experimented upon and brought into the market, examples being coumarin (Fig. 1) (in the year 1866), salicylaldehyde (Fig. 2) (1876), vanillin (Fig. 3) (1876), phenylacetaldehyde (Fig. 4) (1883), piperonal (Fig. 5) (1890), musk xylol (Fig. 6) (1891) and b-ionone (Fig. 8) (1893) (Frater et al., 1998).

Biology, the science of living organisms, is linked with microscopes, test tubes and Petri dishes, but these conventional methods are changing with the advent of Bioinformatics. Due to the advancement in molecular biology and genome sequencing techniques, there is an overflow of biological information. This flood of information has led to a requirement for computerized databases to store and organize the data and to design specialized computational tools to view and analyze the data. Accordingly Bioinformatics can be defined as conceptualizing biology in terms of macromolecules (in the sense of physical-chemistry) and then applying “informatics” techniques (derived from disciplines such as applied maths, computer science and statistics) to understand and organize the information associated with these molecules on a large-scale (Tramontano, 2007).

The term Geographical Indications (GIs) attained significant status in trade agreement negotiations after the establishment of World Trade Organization (WTO).Under WTO, Agreement on the Trade Related aspects of Intellectual Property Rights (TRIPs) sets forth standards to regulate international intellectual property protection and enforcement and establishes international minimum standards for GIs. Geographical Indications identify goods that have a specific geographical origin and possess a quality, reputation or other characteristics which are due to that place of origin. Geographical Indications are now widely accepted as valuable marketing tools in the global economy and are useful to protect rights of communities. Geographical Indications are not granted to individuals but are granted to the group/association of producers as the symbol of collective ownership.

Vegetables have got an important place in agriculture development, human diet and economy of the country. All the developed and developing countries realized the importance of vegetables an essential diet due to medicinal and nutritional value for human health. There is a steady upward trend in vegetable production. China is ranking first in the world and currently produces 237 million tonne of vegetables. India has made a quantum jump in vegetable production securing the second position in the world. The total production of vegetable is more than 91 million tonne in the country. Diseases and pests are the most important factors for low vegetable production. Various fungi, bacteria, viruses, phytoplasmas, nematodes and weeds are responsible for causing diseases in vegetables resulting heavy reduction in yield and quality.

INTRODUCTION

Plant diseases need to be managed for maintaining the quality and abundance of food, feed, and fiber produced by growers around the world. Different approaches may be used to prevent, mitigate or control plant diseases. Beyond good agronomic and horticultural practices, growers often rely heavily on chemical fertilizers and pesticides. Such inputs to agriculture have contributed significantly to the spectacular improvements in crop productivity and quality over the past 100 years. However, the environmental pollution caused by excessive use and misuse of agrochemicals, as well as fear-mongering by some opponents of pesticides, has led to considerable changes in people’s attitudes towards the use of pesticides in agriculture. Today, there are strict regulations on chemical pesticidal use, and there is political pressure to remove the most hazardous chemicals from the market.

Abstract

Surveys made systematically in different remote places of Tamil Nadu brought to light more than 1000 indigenous techniques adopted for pest control in various crops of agriculture, horticulture and store grains. Target animals included array of insect species and animal pests namely rodents, mites, molluscs and microbes like nematodes and viruses. Various kinds of plant species reveal their modes of action distinctly.

Abstract

Plant roots influence the biological, chemical and physical properties of rhizosphere soil. These effects are a consequence of their growth, their activity and the exudation of organic compounds from them. There is now considerable scope for the new ideas to be extended to the rhizosphere. The role of soil microorganisms in sustainable productivity has been well construed. In recent years, root inhabiting (rhizozosphere) bacteria (rhizobacteria) is gaining importance. The beneficial effects of plant growth promoting rhizobacteria (PGPR) has been variously attributed to their ability in improving the crop production, protection against phytopathogens, soil health and environmental quality. However, there is a need for isolation, identification and improvement of potent PGPR’s to utilize them ultimately as promising bio-inoculants. This review embodies some recent developments to evolve strategies for the better biotechnological exploitation of PGPR’s.

Systematic management of plant diseases dates back to 1885 with the invent of Bordeaux mixture by Milardet. Thereafter, a number of contact and systemic fungicides have been reported over the years for the management of various plant pathogens, of which many have become obsolete and many are still being used with excellence. However, the ecological hazards caused by the chemical fungicides have prompted scientists to search for other avenues of crop protection. Most of the conventional chemical and biological plant protection procedures, as well as the use of disease-resistant cultivars, tend towards the direct control of pests and diseases by their elimination. But these practices generally and particularly in case of monoculture crops like rice, raise problems. The risk of developing pesticide resistance in plant pathogens is enhanced by the long term use of the same chemical. The resistance genes of the plants can also be overcome by changes in the pathogens. Therefore the situation demands development of new strategies for plant protection which can supplement the use of resistance breeding and chemical control.

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.

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.

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. 

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,

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.

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.

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 : 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 : 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 : 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 : 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 : 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 : 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   : 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 : 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 : 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 : 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 : 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 : 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 : 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   : 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   : 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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : 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 : 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.