eChapters

1. INTRODUCTION

Organic farming systems can deliver agronomic and environmental benefits both through the structural changes and the tactical daily management of the farming system. The benefits of organic farming systems are relevant both to developing and developed nations which helps for environmental protection, biodiversity enhancement, reduced energy use and CO₂ emissions (Thiyagarajan, et al., 2003). The post Green Revolution era has led to environmental pollution due to excessive use of agrochemicals and fertilizers and thus threatened the fragile ecosystem (Selvaraj et al., 2001). Organic farming conserves soil fertility and curtails soil erosion through implementation of appropriate conservation principles (Thampan, 1995). Organic farming leads to live in harmony with nature.

United Nation experts indicate that organic foods have the good opportunities for developing countries to open a space in the global market. This entails the creation of greater awareness of trade opportunities for organic products as well as of the environmental, economic and social benefits to the public.

1. INTRODUCTION

India is traditionally rich on agricultural knowledge. Presently modern farming is not sustainable in consonance with economics, ecology, equity, energy and socio–cultural dimensions. Indiscriminate use of chemical fertilizers, herbicides and pesticides to boost the yields have resulted in various environmental and health hazards along with socio–economic problems. The agricultural production has continued to increase, but the trend in productivity has started declining. The agricultural scientist’s and farming community whole heartedly aim at an alternative sustainable farming system which will be ecologically sound, economically viable and socially acceptable. The answer to the problem lies in refining our own traditional practices based on natural and organic farming methods offering several safe, feasible and cost effective solutions.

The term ‘Organic farming’, a system of farming is one which avoids synthetic fertilizers but rely upon crop rotation also using crop residues, animal manures, legumes, green manures, biofertilizers, organic wastes etc., to maintain the soil fertility and increase productivity. This system enables the nutrients leaching from perennial wood and vegetation and help to maintain organic matter and protect the soil from surface erosion. The world wide awareness for adopting organic farming has paved way for streamlining the production technology and certification by adopting the specified crop production practices. Organic farming practices in agriculture and animal husbandry are native to East Asian countries, like India and China. In China a strong national movement for animal waste recycling is in vogue, minimizing the use of inorganic fertilizers (Xu, 2000), while in our country specific crop production practices are developed in isolation and adopted locally.

The trend of use of chemicals and industrial inputs in intensive farming is increasing which resulted in soil health deterioration and increased environmental pollution which causes a great concern all over the world. Therefore an emphasis on the need to use the organics and other byproducts of agriculture and industry is emerging. Fortunately, the country is already rich with left over crop residues (185 million tonnes) but its use presently is limited. Apart from crop residues, there is an enormous quantity of cattle wastes out of which sixty per cent of the used for fuel purpose in rural areas.

1. INTRODUCTION

‘Fertigation’ is the technique of supplying dissolved fertilizer to crops through an irrigation system (Haynes, 1985). When efficient irrigation system combined with both nutrients and water, it can lead to obtain higher yield and preferable quality desired marketable produce.

Often, side-dressings of straight solid fertilizers are found to be the management constraints. Most of the growers have the experience of how much the applied fertilizer is either washed from the soil in run-off or leached below the root zone.

Continuous small applications of soluble nutrients have the benefits like labour, due to fertilizer being placed uniformly around the plant roots and allow savings/economy rapid uptake of nutrients by the plant.

1. INTRODUCTION

The basic principle of plant breeding is the utilization of existing variation and creation of new variations. Ploidy breeding is one of the tools used for improving the crop plants. The year 1937 can be considered as a landmark in the history of plant breeding. The discovery of the specific action of colchicine in inducing polyploidy has provided the breeder with a means for increasing the scope of crop improvement apart from the removal of the barrier of sterility in the sterile interspecific hybrids by the production of amphidiploids and their utilization later for the transfer of useful genes from the wild parents to cultivated plants. It was hoped that the production of autoploids in various crop plants would directly lead to the cultivation of better plants, as generally the autopolyploids are known for their gigas characters including the seed.

1. INTRODUCTION

Today’s technological advancement have reached a level where a farmer can have access to information and tools to manage his mechanized field operations. They can now measure, evaluate and deal variability with infield (e.g. soil fertility, water availability and yield) that was known to exist previously but was not manageable, to his advantage. The ability to handle variations in productivity within a field and maximize financial return, reduce waste and minimize impact on the environment has always been the objective of an enterprising farmer, especially those with limited land resources and those who advocate sound agriculture practice.

This concept is not new. What is new is the ability to automate data collection and documentation and the utilisation of this information for strategic farm management decision in the field operations through mechanisation, sensing and communication technology. Such an approach in agriculture production management gives rise to what is now termed as Precision Farming (PF), Precision Agriculture (PA), Prescription Farming (Precision farming), Site Specific Agriculture (SSA), Soil Specific Crop Management (SSCM), Spatially Variable Crop Production (SVCP) etc.

1. Introduction

2. Human Genome Project

3. Development of Bioinformatics

3.1. Indian scenario

4. Plant Genome Model

5. Components of Plant Genome Database

5.1. Stock centre databases

5.2. Genome mapping database

5.3. DNA sequences

6. Agricultural Research Service and National Research Initiative

6.1. Objectives of plant genome programme

6.2. GIBN Trans – pacific digital library experiment plant genome databases

7. Plant Genome Databases

7.1. Vegetable genome databases

7.1.1 Mendel-Plant Gene Nomenclature Database

7.2. Others

7.2.1. Bean Genes – Phaseolus / Vigna sp. Database

7.2.2. Solgenes Database

7.2.3. Soybase

7.3. Other data bases

7.3.1. PGDB (Pathway genome data base)

7.3.2. Demeter’s genome

8. Tools of Bioinformatics

9. New Directions in Genome Database at Stanford

10. Navigating the World Wide Web

11. Virtual Genome Centre (VGC)

11.1. Programmes at the VGC

12. Impact of Gene Chips and Micro Arrays

13. Applications and Impacts

14. Bottlenecks

15. Future Thrust

Wide hybridization (interspecific/intergeneric) is basically attemped to introduce new genetic variability from wild or distantly related species into cultivated ones or to synthesize new plant type/s like Triticale and Raphanobrassica. Majority of the commercial crop plants are usually deficient for one or the other desirable traits which are usually available in their wild relatives. However, crossability between commercial varieties and their wild relatives is very limited which is naturally imposed by certain genetically controlled reproductive barriers. These reproductive barrier/s usually operate either at pre or post fertilization stage/s in plant species (Stebbins1958). Since a species is constituted of individuals who share a common gene pool, reproduce among themselves only / exchange genes and share a common habitat. Hence at natural level gene flow remains strictly confined only among members of a particular species otherwise among the members of unrelated species a genetic barrier exists to create reproductive isolation. Therefore, wide crossing basically requires the overcoming of such barriers whch are imposed by temporal and spatial isolation of parents. The reproductive isolation consists of premating and post mating isolation mechanisms like habitat isolation or geographical isolation, sexual isolation and mechanical barrier depending upon incompatibility or mismatching of ganitalia (animals). Sexual isolation in animal kingdom is usually enforced by type of sexual displays and mating calls which are attractivce only to particular members of a species , however other potential intermating species also do exist in the same habitat or locality at that particular period of time.

The newly synthesized autopolyploids, having few or more undesirable features, e. g; meiotic instability, low seed setting and late maturity etc, are usually not suitable for immediate commercial use, are known as raw polyploids. This is specifically more applicable for those sexually propogated polyploids which are developedfor seed. In early generations due to polyploid chromosome constitution and polysomic inheritance they predominanantly do not breed true. Further more, due to meiotic instability chromosome number in their progeny is not always constant or equal to as in synthesized autotetraploid which may vary from few more to few less than the standard autotetraploid. The raw polyploids usually reverts back to diploid parental constitution due chromosome elimination (Randolph and Fischer, 1939). The mechanism responsible for reverting back to diploid status is similar to that of which give rise haploids from diploids. Presently cases are known where either spontaneously or due to specific treatments the chromosome number was reduced to half in somatic tissues. The phenomenon causing such chromosomal reduction is termed as somatic reduction or reduced mitosis Earlier reports suggested it probably to be caused due to spindle organizer abnormalities or some other unknown mechanism/s. The treatment of seed or seedling by colchicine, chloramphenicol and paraflurophenylalanine are reported to have induced chromosome reduction and production of haploids.

The intervarietal chromosome substitution lines of wheat (T. aestivum) are utilized to study the effects of individual whole chromosome/s on agronomic characters of interest to improve crop plants to be selected for preferred traits (Law and Worland 1973). The common method to develop subsitutiion lines involves development of monosomics lines first of that variety which are used later as recipient variety or recurrent parent for substitution. Presently monosomic lines of several wheat varieties are available. However, the development of substitution lines for a specific chromosome by using monosomics sometimes may be erroroneus due replacement of specific monosome by another one of the 21 chromosome set from the donor to the recipient and consequently monosomic becomes monosomic for another chromosome or a recombined chromosome (univalent shift.). Therefore, to maintainand confirmthe identityof a chromosome involved in monosomy are tagged with either genetic marker/s or confirmed cytologically or with the help of molecular markers.

The chromosomes provide physical basis by which genetical stability and continuity of individuals and populations are maintained in each generation. Chromosomes also play an important role to generate variation which is an essential component of evolutionary process. Although crossing over during meiosis is responsible for generation of variability, but structural changes in chromosome too are important for causing variation and evolution, since genetic and cytological analysis of individuals of related species or isolated populations within the species have shown that they may differ by various kinds of changes in their chromosomal structure. The structural changes usually may result from spontaneous chromosome breakage. But under normal condition/s such breakage is an rare event and its frequency is dependent upon environmental conditions, i.e., temperature, various high energy radiations (e.g. X, λ and β-rays) and some chemicals. Chromosome breakage is reported to be higher in some hybrids and in presence of particular genes. Certain chromosomes and chromosomal segments (centromeric and other heterochromatic regions) are more likely to undergo breakage. But stability and continuity of structural changes in the chromosomes depend on the behavior of the broken ends. There is no change if broken end rejoins at the same chromosome but a change may occur if it rejoins with the end of other chromosome or if remains unattached. In case of a pair of homologous chromosomes if one chromosome has any structural change and other one is normal we customarily call it a structural hybrid.

The relationship between gene and chromosome was suspected at the time of rediscovery of Mendelian^, Laws. During that period Montgomery (1901) and Walter Sutton (1902) working on grasshoppers showed that chromosomes occur in distinct pairs, often of recognizable shape and size, and that synapsis involves the union of maternal and paternal chromosomes, while Winiwarter (1901) concluded from his studies in rabbit ovaries that bivalents in the first meiotic division resulted from the chromosome pairing side by side and not end to end as believed by some other workers of that time . Theodor Bovery (1902) showed from his work on polyspermy in the fertilization of sea urchin eggs that the chromosomes of an individual were not equivalent (genetic information) to one another and hence a full chromosomal complement is essential for normal development of cell. Correns (1902) and Cannon (1902) pointed out close parallelism between Mendelian segregation and chromosome reduction during meiosis and concluded that genes are located on chromosomes but they, like de Vries, supposed that maternal and paternal chromosomes move to opposite poles during meiosis. In the same year Guyer established an understanding that random assortment between different pairs of chromosomes would give the independent assortment of genes required by Mendel. Ultimately Sutton (1903) brought together the ideas from cytology and genetics to clearly show the role of chromosomes in heredity and hence to establish the field of cytogenetics. Boveri also through his work, advanced many of the same ideas and thus the hypothesis correlating genes and chromosome transmission was established, which is known as the “Sutton-Boveri Hypothesis or chromosome theory of inheritance”.

Most of the DNA of an living organism is packaged and organized in a chromosome as well as in mitochondria and cell organelles (Feulgen and Rossenbeck 1924). DNA is not found on its own but rather is structured in long strands wrapped around protein complex called nucleosome consisted of a protein called histone. During most of the duration of cell cycle a chromosome consists of long double helix DNA molecule (with associated proteins)During S phase the chromosome gets replicated resulting in X –shaped structure (chromatids) and still attached to a single centromere. The basic role of the chromosome is to provide a frame work which allows each linear segment of the genome to replicate and segregate efficiently. Failure in either of processes cause chromosome imbalance in daughter cells. Three specific cis-acting sites are required for stable chromosome maintenance, i.e., an origin of replication, a centromere and telomeres.

Classical studies of the morphologyof individual chromosomesof the plant species begun by S. Nawaschin 1910-16 and continued by Taylor (1925), Sharp (1929) and Mc Clintock (1929-30). And eventually it was possible to set up working models which account for the internal structure and chemistry of the chromosome and the genetic material as well as genetical facts. The use of aceto-carmine with iron (Belling, 1921) and application of heat greatly improved the staining differentiation of chromosomes. Smears have practically replaced the paraffin techniques of studying chromosome. The gross morphology of chromosomes is generally worked out either at prophase stages of meiosis or metaphase in somatic tissues. The chromosomes may differ in thickness, total length, position of centromere or spindle fiber attachment region, chromomere pattern and number and position of secondary constriction. The total length of chromosomes at metaphase also differs in different tissues of a species and also in certain tissues chromosome present may be very different in appearance. Figure 1 shows various morphological features of a eukaryotic chromosome

Edaphology is the study of soil properties in relation to plant higher production.

Pedology refers to study of origin of soils in their natural environment, classification and description.

pH is the negative logarithm of the concentration of H+ ions in soil solution.

Soil profile is a vertical exposure of horizon sequence.

Soil texture is not changed by cultural management.

Cation exchange capacity (CEC) is defined as sum total of exchangeable cations that a soil can absorb.

Abscission: The shedding of leaves, flowers or fruits as a result of formation of layer of loosely adhering cells at base that breaks apart readily.

Accent: It is created in the garden to avoid the monotonous view. Mostly unusual object like tall fountain, tree, statue etc are used to create the effect

Acre: A unit of measurement of land area equivalent to 4840 square yards or 0.4047 hactare.

Acropetal: Developing sequentially from basal to the apical position.

Acrylic: It is a glassy thermoplastic that is incorporated in rigid plastic to enhance wither ability.

Aestivation: The use of high temperature to promote flowering.

After-ripening: Physiological changes that take place within a dormant seed or bud during dormancy or It is a type of embryo maturation which enables germination of seeds.

Floriculture is the aesthetic branch of horticulture which deals not only with the cultivation of ornamentals, annuals, biennials and perennial plants but also with their marketing. Flowers symbolize beauty, purity, peace and love. In India, it is a dynamic and expanding industry showing an impressive annual growth rate.

Classification of Flower Crops

The flowering plants can be classified broadly on the basis of their species, genus, family, plant part used or type of flower plants. They are further classified as cutflowers, cut foliage, turfgrasses, groundcovers, hedges, accents, specimen plants, avenue trees, screens, topiaries, fillers and others.

Vegetables are rich source of vitamins, minerals than other than nutrients. In India, vegetables occupy only 2.8% of the total cropped area. Vegetables are (except mushroom) grown for their succulent and edible parts such as the roots, stems, leaves, young tops, fruits or seeds which are used in culinary preparations either fresh or preserved in the fresh state.

These crops are further classified into different groupings according to similarities in edible parts, growth habits, methods of culture and botanical family.

Classification refers to grouping of individuals with similar identities related to genetic make up, evolution or climatic requirements. The major units are order, family, sub-family, genus, species, variety/cultivar and strain. Monocotyledonous and dicotyledonous are two major classes and most of the fruits are covered under dicotyledonous family. Different basis of classification of fruits are: Botanical; Ecological; Stem morphology; Fruit morphology; Flowering habit; Respiration rate; Photoperiodism; Shade tolerance; Drought tolerance; Soil texture and topography; Soil reaction; Soil tolerance; Horticultural; Bearing habit; Inflorescence type; pollination types; Type of self incompatibility; Type of dichogamy; Edible parts; Center of origin; Ploidy levels; Longevity of fruit crops; Fruit size and Nutrient contents of fruits.

11.1 Planning

• Upon receipt of production program verify that crop sowing dates fall into crop windows identified for the particular area and allot accordingly. Check the quality of lots produced in previous season, if available.
• Assign crop location (Open field, Green house, Insect Proof Net / Cage etc) according to crop needs, site conditions and degree to which these conditions can be manipulated efficiently to meet the crop needs. Always adhere to optimum crop conditions.
• Identify material and personnel needs based on the production program and coordinate timely arrival of both. Material and personnel must meet standards established by the production site.
• Identify material quality like A, B, D (First, Second and Dirty) based on the specs.
• Refer standard procedures or formulate some of them. Do not proceed if proper documentation does not exist.
• Plan training for laborers regarding crossing, flower morphology, anthesis, time of stigma receptivity etc.

Inventory management system is a computer based system for creating work orders at a processing plant, tracking inventory levels in the go downs, , sales and seed movement out of the processing plant. These modern systems avoid book maintenance and save lots of space. It will also tool for avoiding overstock or delay in movement of seed material for packaging. In most of the processing plants SAP is the most popular inventory management tool which is more efficient than others. SAP is basically a tool of enterprise resource planning which help in material management. The customised software can be used very effectively in a processing plant for the following operations.

Seeds are having a ability to survive and start a new generation when favourable conditions exists. However like other form of life, they cannot retain their viability indefinitely and eventually deteriorate and die. To retain viability and germination it is important to store in proper storage. Seeds harvested may not be useful for packaging thus making it to store for a period till the need for packaging arises. Seed storage is very critical task of seed processing. The success of seed processing is determined by safe storage. Since the vegetable seeds are expensive need modern techniques of storage. Based on the seed shelf life or longevity vegetable seeds can be divided into two types:

Orthodox Seeds : Orthodox seeds are long-lived seeds. They can be successfully dried to moisture contents as low as 5% without injury and are able to tolerate freezing temperatures. Most orthodox seeds come from annual temperate species adapted to open fields. At physiological maturity they contain moisture content of 30 – 50%. Most of the vegetable seeds are orthodox and hence there is lot of scope for proper storage. E.g-Tomato (6.0 %) and Peppers (7.0%

Recalcitrant Seeds : They are short - lived seeds, which cannot be dried to moisture contents below 30% without injury and are unable to tolerate freezing. They are difficult to ore successfully because of their high moisture content encourages microbial contamination and results in more rapid seed deterioration. Storage of these seeds at subzero temperatures causes the formation of ice crystals, which disrupts cell membranes and causes freezing injury. These seeds are from perennial trees in the mois t tropics such as coconut, coffee, cacao, citrus etc. These seeds mature and exists in their fruits and are covered with fleshy or juicy ariloid layers and impermeable testa. At physiological maturity they contain more moisture content (50- 70%) than orthodox seeds, even though their embryos are only about 15 % of the size of an orthodox seed embryo. In general recalcitrant seeds never go into dormancy but instead continue their development and progress towards germination.