eChapters

1.1. Origin and distribution

• Centre of origin is Central Asia, the Near East, Ethiopia and the Mediterranean
• There are two sub-species
  • Pisum sativum sub. sp hortense, the garden pea
  • Pisum sativum sub. sp arvense, the field pea

1.1. Origin and distribution

• Centres of diversity - Central and South America, India, South East Asia with secondary centres of diversity in West and East Africa.
• Leaf amaranth - native of India
• A. tricolor L. (Syn A. gangeticus L), A. mangostanus, A. polygonoides, A. dubius, A. blitum (Syn: A. lividus)
• A. tristis L., A. viridis L. - Wild leaf types
• A. spinosus L., A. cruentus L., A. caudatus L. - Cultivated grain types

10.2. Breeding Objectives 10.2.1. Tomato • To develop early , high yielding and consumer preference varieties / hybrids. • Large round fruit with adequate firmness and shelf-life, uniform fruit sizes shape, red colour and freedom from external blemishes or abnormalities for fresh market. • Large fruit size, high fruit quality and continuous production for home garden tomatoes. • Deep, uniformly red coloured tomatoes , pH below 4.4, high total soluble solid (4.5-7) and high alcohol solids (AIS) in processing tomatoes. • To evolve varieties / hybrid resistant to diseases like fusarium wilt, verticillum wilt, late blight, early blight, septoria leaf spot, anthracnose, bacterial wilt, bacterial canker and tomato leaf curl virus. • To develop varieties/ hybrids resistant to root-knot nematodes. • To breed varieties/ hybrids suitable for abiotic stresses like low Day (K10o C) and high temperatures (day 35+2o C) excess and moisture deficient, salt etc. • To develop varieties/ hybrids for prolonged storage and transportation

Any new variety produced by the Scientist has to be multiplied to many times to meet the needs of the farmers. In order to ensure the availability of quality seeds, Government of India have enacted Seed Act 1966 and Seed Rules, 1968. The Seed (Control) order 1983 was promulgated under essential commodities act, 1955 in order to ensure the production, marketing and distribution of the seeds.

1. SEED ACT 1966

The objective of Seed Act is for regulating the quality of certain notified kind / varieties of seeds for sale and for matters connected therewith. The Seed Act passed by the Indian Parliament in 1966 was designed to create a ‘climate’ in which the seeds man could operate effectively and to make good quality seed available to cultivators. Seed Rules under the Act were notified in September 1968 and the act was implemented in October 1969. This act extent to the whole of India and it has 25 sections.

Seed

A seed is a mature ovule consisting of an embryo together with stored food, all enclosed by a protective coat. It is product of the ripened ovule of gymnosperm and angiosperm plants which results as a consequence of fertilization and some growth within the mother plant formation of seed completes the cycle of reproduction. The embryo develops from zygote and the seed coat from the integument of ovule. A seed has three main parts these are seed coat, endosperm and embryo. Embryo includes the root, the cotyledon and embryonic leaves. Seed is located inside fruit and a fruit is a mature ovary. In broad sense any plant part which is used for commercial multiplication of crop is called seed. Thus in case of potato stem and tuber are also known as seed. Improved seed results in (1) Better germination (2) Vigorous seedling growth (3) Higher crop stand (4) Better quality of produce (5) Ultimately in higher crop yield.

Development of seeds: Successful pollination and fertilization are the prerequisites to produce a viable seed. During pollination the pollen grains are transferred from anther to the stigma and get stuck there in the sticky fluid secreted by the stigma. The fluid contains sugar which induces germination of pollen grains. The pollen tube grows downward through the style in the ovary until it reaches the embryo sac and discharges two male gametes-one is fused with a female gamete and forms the zygote (2n) and the other is united with two pollar nuclei to produce endosperm (3n). The zygote develops and gives rise to embryo embedded in nutritive tissue developed from endosperm. The nucellus tissues surrounding these structures provide necessary energy for their proper development. Like fruit, the seed also exhibits sigmoid and sometimes double sigmoid pattern of growth. Various changes occur during the course of seed development and the sequences of development may vary from species to species keeping the basic theme unaltered.

1. SEED

A seed is defined as a ‘mature ovule’ or a reproductive unit formed from fertilized ovule, consisting of an embryo, reserve food and a protective cover.

Seed is the basic input in agriculture upon which other inputs are applied. A good vigorous seed utilities all the resources and realized as a reasonable output to the grower. It is wealth to the farmer, it is the yesterday’s harvest and tomorrow’s hope. Good seed in good soil realize good yield.

Seeds exhibit a great range of variation in shape, size, colour and behaviour. The most essential factor for the success of plantation is the ready availability of quality seeds. The quality of seed is totally responsible for the future return / performance of each and every seedling.

Seed
The seed, in botany is a mature ovule, consisting of an embryo together with a store of food all surrounded by a protective coat and bear ability to develop a new plant on optimum conditions of soil, moisture and light. It usually develops after the fertilization on an egg cell by male generative cell from a pollen grain. Seeds of some species develop without the intervention of the male cell, formed entirely of ‘mother’ tissue. Such seeds are called apogamic seeds. In seed technology, the seed is seed or any vegetatively propagated material produced from seed crop in accordance to Indian seed standards and has potential to develop new crop in presence of soil, moisture and light.

Archaeobotany

Botany as far as it is relevant in archaeology mainly denotes all types of ancient organic material (in particular ancient plant remains) collected from excavation sites. The deliberate study of the interrelationship between humans and plants and the environmental context in which this occurred has been called archaeobotany.

Introduction

Since beginning of this century genetic diversity of agricultural crop has been lost due to several reasons (Marla, 2012). Genetic erosion is caused by human intervention, mono culture, green revolution especially due to commercialization of plant breeding. So there is urgent need to collect, conserve plant genetic & genomic resource for further use.

A seed bank stores seeds to preserve genetic diversity. There are many reasons to store seeds. One reason is to have on-hand the genes that plant breeders need to increase yield, disease resistance, drought tolerance, nutritional quality, etc. of plants used in agriculture (i.e., crops or domesticated species). Another reason is to forestall loss of genetic diversity in rare or imperiled plant species in an effort to conserve biodiversity ex situ and in situ. Many plants that were used centuries ago by humans are used less frequently now and seed banks offer a way to preserve that historical and cultural value. Collections of seeds stored at constant low temperature and moisture guard against loss of genetic resources that are otherwise maintained in situ or in field collections. These alternative ‘living’ collections can be damaged by natural disasters, outbreaks of disease or war. Seed banks are considered seed libraries and contain valuable information about evolved strategies to combat plant stress or produce novel products. The work of seed banks spans decades and even centuries. Most seed banks are publicly funded and seeds are usually available for research that benefits the public.

Methods in Seed Blending

For good seed blending there are three methods and details of which given as below:

The term seed blending is nothing but seed mixing done based on certain principles. It is simply combining two or more seed lots of same variety or hybrid of specified quality. The blendingmayinvolve lots which mayhave different quality in terms of germination. Usually individual seed lots are much better compared to blended lots but from the point of efficient inventory management blending is advisable. The main purpose of blending is to pool all the variable lots in to a larger bulk and mix the constituents effectively so that each pocket of seed has a uniform quality.

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.

1. MINIMUM SEED CERTIFICATION STANDARDS

In a seed quality control programme through seed certification, the minimum seed certification standards, in fact, are the minimum standard conditions which must be met. The minimum seed certification standards, thus are the standards required for the certification of seeds by the certification agencies.

The minimum seed certification standards can be broadly grouped into two groups.

Previous Year Questions

1. Different Classes of Seeds?

2. Various parameters of field & seed standards for breeder seed production?

3. Factors that affect the longevity of seeds during storage in warehouses?

4. Initial Seed Quality?

5. Seed Testing?

Different Classes of Seeds

1. Nucleus Seed: It is handful of seed maintained by concerned breeder for further multiplication. The nucleus seed will have all the characters that the breeder has placed in it and it is of highest genetic purity. The quantity of nucleus seed is in kilograms.

2. Breeder Seed (BS): Breeder seed is a seed or vegetative propagating material directly controlled by the originating or sponsoring plant breeder of the breeding programme or institution and or seed whose production is personally supervised by a qualified plant breeder and which provides the source for the initial and recurring increase of foundation seed. Breeder seed is exempted from certification. However, the breeder seed crop is being inspected at appropriate stages by a Monitoring Team consisting of breeder, representative of NSC and representative of Seed Certification Agency. The breeder seed lots are affixed with Golden Yellow tags. The genetic purity of breeder seed crop should be maintained at 100 per cent.

1. SEED CERTIFICATION

Seed Certification is a legally sanctioned system for quality control on seed multiplication and production. It involves field inspection, pre and post control tests and seed quality tests.

1.1. Phases of Seed Certification

Certification shall be completed in six broad phases listed under

Introduction

Seed certification is a legally approved system for quality control of seed multiplication and production. Seed certification procedures are designed to ensure physical and genetic purity, freedom from other crop seeds, objectionable and other weed seeds and designated diseases with good germinability of the foundation and certified seed. Seed certification is done by the State Seed Certification Agency of the concerned state (SSCA) notified under section 8 of the Seeds Act, 1966 or by National Seed Corporation (NSC), where State Seed Certification Agency does not exist. The General Seed Certification Standards are applicable to all crops, which are eligible for certification, while field and seed standards are applicable to individual crop, constituted as the minimum seed certification standards. The word ‘seed’ or ‘seeds’ as used in these standards also includes all the propagating materials. Seeds or propagating material, which does not meet the standards of seed certification prescribed in the Indian Minimum Seeds Certification Standards, 2013 (Gunasekaran and Trivedi, 2013), are not certified by the Seed Certification Agency. The general seed and field standards for various crops are given at the end of this chapter.

Seed multiplication and production was controlled by a legally sanctioned system called Seed Certification. Seed certification procedures and designed to ensure physical and genetic purity, freedom from weed seeds and diseases and good germinability of the certified seed. Seed certification is done by the Seed Certification Agency (SSCA) of the concerned state or by NSC.
 
Objectives of Seed Certification

The objective of seed certification programme was formulated by Douglas, 1971
 
i)    to ensure genuineness and quality of seed.
ii)    The identification and their rapid increase of new varieties under accepted names.
iii)    The systematic increase of superior varieties
iv)    Continuing supply of quality material and their maintenance.

Seed certification

It is a legally sanctioned system for quality control and seed multiplication and production. It involves field inspection, pre and post control tests and seed quality tests. As per Indian Seed Act seed certification is voluntary and it is not compulsory. The seed that is sold in the market is of two types certified seed or truthfully labelled seed. Whereas truthfully labelled seed is one which is being produced and marketed by the producing company by maintaining the labelling standards.