eChapters

Plant breeding is described as an art and science of changing the genetic architecture of plants with a goal towards betterment of mankind. Apart from this generalized concept, plant breeding is accomplished through inter-disciplinary mode assorted from simple selection in a variable plant-population having some desirable traits to the application of biotechnology and more. Worldwide, cultivars of different crops are routinely manufactured by Multinational and National level Industries, Government Institutions, Universities, Crop specific Organizations, professional plant breeders and even by the individuals such as gardeners and farmers.

Plant breeding is basically operated by the principles of Genetics where selections are practiced from a variable population and the selected variation needs to be inherited. Three categorized broad goals of plant breeding are 1) high yield 2) uplift in quality and 3) resistance against biotic and abiotic stress.

Spice crops are known to add nutritive value and increase the palatability as well as quality of food. Therapeutic uses of spices are also well recognised. The spice industry in India and trade has shown stunning progress over the last 5 years with 120% increase in revenue which is very close to touch $ 3 billion. East Asia is the major market for spices, followed by America and the European Union and the world spice trade has almost touched $ 17 billion by 2020. So, increased production is of paramount importance across the world and the potential is increasing. On the other hand, quality improvement is one of the primary objectives of spice crop breeding apart from achieving high yield. Cultivar and species diversity are the principal components of diversity of spices (Sasikumar et al. 1999; Krishnamoorthy et al., 1997; Prasath and Venugopal, 2004). A good amount of variability is found in many important Indian spices like black pepper, cardamom, cinnamon, curry leaf, ginger, garcinia, tamarind and turmeric. A number of cultivars have been released followed by intra-germplasm evaluation and selection in spices. Contribution of recombination breeding is less in spice crops with regard to other field crops and a number of valuable varieties have been bred by clonal and seedling selection (Peter, 2008). Deployment of high yielding, water use efficient, climate resilient genotypes and technologies are also necessary.

1. DUS TEST

A variety shall express distinct character(s) for verification, uniformity within population and stability for expression of such characters over the year and at different locations, then only its genetic purity is confirmed.

1.1. Requirements

Authentic seeds of existing varieties, pure seeds of variety under tests, list of characters to be examined and their expression.

This test is conducted in the most optimum conditions of soil and climate and the crop is exposed to the best agronomic management conditions to ensure full expression of the characters.

1.2. Distinctness

The variety under test is compared with the existing varieties (having similar plant height, growth habit, days to flowering, days to maturity and reaction to diseases) for qualitative morphological characters at seed, seedling and plant levels. Biochemical differences may also be considered. To establish the distinctness, the test is performed for 2 years for self pollinated crops.

1. PPV & FR ACT

With the signing of TRIPs agreement of the World Trade Organization (WTO), India has agreed to provide protection to plant varieties. The Government of India, therefore, enacted “ The Protection of Plant Varieties and Farmers Rights Act (PPV&FR Act)” in 2001 and the Regulations for implementing the Act were formulated in 2003.

The Ministry of Agriculture, Government of India, has been identified as the nodal agency for implementing the PPV& FR Act through an Authority known as “The Protection of Plant Varieties and Farmer Rights Authority”. The Authority came into force in November, 2005.

PPV & FR act has 11 chapters, 4 schedules and 97 sections.

1. DEFINITION

Seed marketing is the one of the most vital components of seed technology. On it depends the size and scope of the seed industry. Broadly it includes such activities as production, processing, storage, quality control and marketing of seeds.

Seed marketing refers to the actual acquisition and selling of packed seeds, intermediate storage, delivery and sales promotional activities.

1. SEED INDUSTRY BEFORE INDEPENDENCE

The Royal Commission on Agriculture (RCA) constituted in 1925 suggested the following for seed improvement

There should be a separate organization within agriculture departments to deal with seed distribution and seed testing.

The seed distribution enterprise should be self-sustaining.

Seed distribution should be organized through co-operatives, other associations, seed merchants (whenever they are available), through seed agents, as well as through agricultural department staff and any other agency which could be considered suitable.

Seed merchants of proven enterprise should be given every encouragement.

1. NEMATODES

Nematodes, also called eel-worms, are wormlike in appearance, but quite distinct taxonomically from true worms. They live freely in fresh or salt water or in soil. They are saprozoic and also parasitize animals (including man) and plants. Many species of nemotdes parasitize higher plants and cause disease symptoms. Plant parasitic nematodes are small (invisible to the naked eye), long, tubular, round in the cross section, unsegmented and smooth invertebrates. They inhibit different parts of plants, namely, roots, stem, flower buds and seeds. Depending on the host-parasite relationship, plant parasitic nematodes may be sedentary or migratory and ectoparasitic and/or endoparasitic in their feeding habits.

1.1. Nematodes

Seed-borne nematodes may be internal or may occur as seed infestation. Several saprozoic soil nematodes occur in beds of soil mixed with seed. Seed infestation by nematodes does not produce any specific symptoms on seed, but in those that occur as endoparasites, the floral structure may be modified into a seed gall (Anguina spp.) may produce symptoms such as discoloration of testa in groundnut (Ditylenchus destructor) or may be symptomless as in paddy kernels infected by Aphelenchoides besseyi. Neergaard (1979) listed five genera - Anguina, Aphelenchoides, Ditylenchus, Heterodora and Rhadinaphelenchus - that are seed-transmitted. Heterodora and Rhadinaphelenchus occur as endoparasites in roots, stems, and leaves. The latter also affects the growing apex, inflorescence and husks of dropped nuts.

Weight loss: For grains or grain legumes in the tropics, a weight loss in the range of 10-30 per cent might be expected over a full storage season.

Loss in quality/market value: Infested seed is contaminated with insect debris and has increased dust content. Seeds are holed and often discoloured, which fetch low price.

Promotion of mould development: In humid conditions, without adequate ventilation, mould development and caking can spread rapidly, causing severe losses.

Reduced germination in seed material: Damage to the embryo of the seed will usually prevent germination. Some storage pests prefer to attack the embryo.

1. INTRODUCTION

Seed health refers to the health status of a seed. Sowing healthy seeds of high quality is our concern to improve crop yields, thus increasing food production. It has a great concern to farmers and seed producing agencies where the disease is high and average yields are low and where more food is needed to feed the ever-increasing population. So, it is important to test the seeds for disease organism before they are sown in the field and to avoid harmful organisms traveling from infected to non-infected areas within a country or across international boundaries.

1. SEED PATHOLOGY

The area of science that studies the relationship between pathogens and seeds is seed pathology.

2. TYPES OF PATHOGEN

Diseases of plants are caused primarily by three types of pathogens: bacteria, fungi, and viruses. Despite that fungi comprise the largest group of pathogens, the bulk of seed-specific diseases are caused by bacteria or viruses. This is due to the fact that bacteria and viruses are more adopt at entering and then travelling through the veins of the plant, a phenomenon known as ‘systemic infection,’ and from the vascular system may make their way into the developing embryos of seeds.

Fungi, in contrast, tend to be restricted to the outer layers of the plant, where they initiate infection by means of air-borne spores and then proceed to spread by attacking nearby cells of the outer layers. Fungi are much less likely to enter the vascular system of the plant, and thus infect seed mostly when they either ‘crawl’ all the way to seed on the outside of the plant, or else send out spores that land on the seed. In either case, the fungal spores are on the outside of the seed, in the layers of the seed coat, spores on the seed coat are more prone to either dry up and die, or else to get sloughed off with the seed coat during seed germination, thereby failing to cause disease on the next generation of plants.

1. GERMPLASM

A germplasm is a collection of genetic resources for an organism. For plants, the germplasm may be stored as a seed collection or for trees, in a nursery.

1.1. Conservation methods

1.1.1. In situ conservation

The conservation of species in their natural habitats, is considered the most appropriate way of conserving biodiversity. Conserving the areas where populations of species exist naturally is an underlying condition for the conservation of biodiversity. That’s why protected areas form a central element of any national strategy to conserve biodiversity.

1. SEED TREATMENT

It refers to the application of pesticides (fungicides, insecticides or a combination of both) to seeds before sowing and/or storage in order to protect the seeds and young seedlings from soil borne pathogens and/or storage pathogens and insects. Seeds are thoroughly mixed with required quantities of chemicals namely bavistin (carbendezim) @ 2-4 g/kg of seeds.

1. DEFINITION

Seed deterioration is defined as deteriorative changes occurring with time that increase the seed’s vulnerability to external challenges and decrease the ability of the seed to survive

1. SEED STORAGE

Is the maintenance of high seed germination and vigour from harvest until planting.

1.1. Importance of seed storage

Seed storage is important to get adequate plant stands in addition to healthy and vigorous plants.

1. SEED TESTING

The science of evaluating the planting value of seed has been developed to achieve the following objectives for minimizing the risks of planting low quality seeds.

To determine the seed quality and its suitability for planting

To identify seed quality problems and their probable cause.

To determine the need for drying and processing, if any.

To determine if seed meets established quality standards for labeling.

To establish quality and provide a basis for price and consumer discrimination among lots in the market.

Founded in 1924, with the aim to develop and publish standard procedures in the field of seed testing, with member laboratories in over 70 countries world wide. ISTA membership is truly a global network. ISTA secretariat is located at Zurich, Switzerland.

1. VISION AND MISSION

ISTA members work together to achieve their vision of ‘Uniformity in seed quality evaluation worldwide’. The association produces Internationally agreed rules for seed sampling and testing, accredits laboratories, promotes research, provides International seed analysis certificates and training and disseminates knowledge in Seed Science and Technology. This facilitates seed trading Nationally and Internationally and also contributes to food security.

1. INTRODUCTION

For maintenance of genetic purity in the field with the seed crop and to test verify the standards in certification programme, the studies on varietal characterization and identification have attracted the attention of breeders, breeder’s right protection institutions, farmers, the seed industry, certification agencies, and seed testing laboratories with a view to assure the quality of seed marketed to the consumers.

1. DEFINITION

Sum of those properties of seed, which determine the potential level of activity and performance of the seed or seed lot during germination and seedling emergence. i.e., rapid and uniform production of healthy seedling and stand establishment under a wide range of field conditions is considered as seed vigour.

In a vigour test, the seed is introduced to a stressful environment unfavorable to seedling development. This environment can be cool, cold or warm, or a combination of either high humidity and high temperatures, or heavy moisture at low temperatures. A vigor test cannot replace a germination test, but rather supplements it with more information about seed quality.

1. FIELD OF APPLICABILITY

Grow-out test is the official measure for controlling the genetic purity of the seed lot. It serves as ‘pre-control’ as well as a ‘post control’ test for avoiding genetic contaminations. According to the official regulations in India, it is prerequisite for seed certification of hybrids of certain species such as cotton, castor, musk melon and brinjal.

The test is conducted for checking the sellers label with respect to genetic purity status of the seed lot under the provisions of the Seeds Act 1966. In addition, grow-out test can also be used as a measure to judge the efficacy of the certification agency or the inspector.

The relative long periods of time required for completion of germination tests delays the seed marketing. This necessiated the development of rapid methods for estimating the germination capacity of seeds. This test was developed by Lakon (1942) in Germany.

1. PRINCIPLE

It is a biochemical test, in which living cells are made visible by reduction of an indicator dye. The indicator used is 2,3,5 triphenyl tetrazolium chloride. Within the seed tissues, it interferes with the reduction processes of living cells and accepts hydrogen from the hydrogenases. By hydrogenation of the 2,3,5-triphenyl tetrazolium chloride, a red stable and non diffusible substance, triphenyl formazan is produced in living cells (Fig. 1).

1. GERMINATION TEST PROCEDURES

Although several methods are available for germination testing it is suggested that use one of the two major methods described here because these are adaptable to most environments and in general give uniform results Select 400 seeds randomly and used for germination in 4 replications.

1.1. Top of Paper (TP)

Seeds are placed on one or more layers of moist filter paper or blotter paper in petriplates These petriplates are covered with lid and placed inside the gemination cabinet This is suitable for those seeds which required light Cut the paper to the size and shape of the dishes (Fig. 1).

Place a layer of paper in each dish If the paper is too thin use a double layer Label the top and bottom of each dish with the accession number number of the replicates and date of the test Moisten the paper with water (Fig. 2)