eChapters

Generation system of seed multiplication is nothing but the production of a particular class of seed from specific class of seed up to certified seed stage. The choice of a proper seed multiplication model is the key to further success of a seed programme. This basically depends upon,

• The rate of genetic deterioration
• Seed multiplication ratio
• Total seed demand (Seed replacement rate)

Genetic purity is the vital determinant in continuing the genetic integrity in seed from generation to generation. This is the basis of variety purity maintenance. The genetic purity depends upon the purity of the seeds planted. The genetic purity of the seeds planted must exceed or equal to the final product purity standards required as the purity generally decreases with subsequent generations of propagation. The improved varieties loose their identity and healthiness unless properly maintained. Maintenance selection can prevent the seed quality deterioration.

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)

I. FILL UPS

1. _____ number of seeds are used for germination.
2. The seedlings which show the capacity for continued development into normal plant is called_____.
3. The seedlings which do not show capacity for continued development into normal plant is called_____.
4. Seeds which do not absorb moisture till the end of the test period is called _____.

Seed Germination Test

Germination is the process of emergence and development of seed embryo into a plant under favourable environmental conditions of water, soil, sunlight and temperature. The best example of germination is the sprouting of a seedling from a seed of an angiosperm plant. It reflects the ability of seed to produce a normal plant under favourable environmental conditions. The germination rate of a particular seed lot is a key indicator of its performance in the field.

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.

I. FILL UPS

1. _____ is a collection of genetic resources for an organism.
2. The conservation of species in their natural habitats is called _____.
3. _____ is the preservation of components of biological diversity outside their natural habitats.
4. _____ is a type of gene bank that stores seeds as a source for planting in case seed reserves elsewhere are destroyed.

I. FILL UPS

1. _____ seed is one of the oldest condiments the human race has ever known.
2. Sesame seed contains _____ oil and _____ protein.
3. Sesame oil contains about _____ % oleic acid.
4. Isolation distance for gingelly certified seed production is _____.

Global onion research connects crop domestication, genetic diversity, nutrition, therapeutics, production, breeding and post-harvest technology. Onion contains organosulphur compounds, quercetin derivatives and other phytochemicals associated with antimicrobial, antioxidant, cardioprotective and anticancer effects. Despite high global production, productivity differs substantially among countries, and storage losses remain a major economic concern. This chapter reviews global production trends, germplasm resources, breeding strategies, phytochemistry, therapeutic potential and emerging storage technologies. Landraces, cultivars and wild relatives provide valuable traits for yield, storability and stress resilience. Advanced treatments such as ozonation, cold plasma and irradiation demonstrate promise, although wider commercial adoption, economic validation and regulatory development remain necessary.

8.1 Black Pepper Breeding

Black pepper (Piper nigrum L., family:Piperaceae), known as the ‘King of Spices’ and “Black gold”, is one of the important spices since time immemorial and perhaps the oldest spice regarded globally. It is a perennial climber grown for its fruits that are used as spice with plethora of medicinal properties. Black pepper is also very important in traditional medicine (Ravindran, 2000). However, it is mainly valued for its characteristic pungency and flavour, as an ingredient in food preparations and also as a condiment.

Genetic Resources

World’s largest collection of black pepper germplasm is maintained by the Indian Institute of Spices Research (IISR) at Kozhikode, Kerala, containing local cultivars, wild forms collected from the area of origin and related species. At present there are about 3466 accessions, consisting of 1266 wild relatives, 2062 cultivars, in addition to 9 exotic collections maintained in India. These collections were characterized and evaluated to estimate the genetic diversity for various yield and quality characters. Cultivar diversity is one of the principal components of diversity in black pepper. The cultivars are evolved directly from the wild P. nigrum.

India is a leading producer and exporter of onion, but its productivity, market stability and post-harvest efficiency remain constrained. Farmers face fragmented holdings, climate uncertainty, price fluctuations, inadequate storage, technological gaps and significant post-harvest losses. This chapter reviews government programmes and policies related to financial support, irrigation, infrastructure, crop insurance, market access, farmer organizations, storage, processing and agricultural research. It also discusses export-quality requirements, grading, packaging and pesticide-residue standards. Research priorities include stress-resistant varieties and hybrids, drip irrigation, fertigation, growth regulation, sprout control and non-thermal storage treatments. Coordinated policies and technological dissemination can improve farmer income, productivity, quality and market resilience.

I. FILL UPS

1. The isolation distance for seed crop of greengram must be _____.
2. Spacing adopted for greengram seed production is _____.
3. Seed rate of greengram is_____.

I. FILL UPS

1. Groundnut contains _____ oil.
2. Groundnut contains _____ protein.
3. Groundnut is a _____crop.
4. Stigma receptivity is for _____ after anthesis.
5. Fertilization occurs about_____ after pollination.

I. FILL UPS

1. _____ is the official measure for controlling the genetic purity of the seed lot.
2. _____ serves as ‘pre-control’ as well as ‘post-control’ for avoiding genetic contaminations.
3. _____ can also be used as a measure to judge the efficacy of the certification agency or the inspector.
4. The minimum population requirement for taking the observations shall be _____ plants.

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.

2. METHODS OF HARVEST

The seed can be harvested either manually or mechanically. In mechanical harvesting, single harvest is possible, but care should be taken to avoid mechanical injury. In manual harvesting, crops can be harvested either as single harvest or as periodical harvest. The crops having continuous flowering habit are to be harvested in different harvests/ pickings.

2.1. Manual harvesting

Harvesting any crop can be done manually. Manual harvesting is done by the hand of harvest worker. Multipicking in pulses and vegetables is done by manual methods.

I. FILL UPS

1. The type of harvest in paddy is _____.
2. The type of harvest in cumbu is _____.
3. The type of harvest in bhendi is _____.
4. The type of harvest in brinjal is _____.

Substantial onion losses occur after harvest through sprouting, rotting, physiological weight reduction and quality deterioration. Proper harvest timing, careful handling and effective curing are therefore essential for maintaining marketability and extending storage life. This chapter explains maturity indices, including appropriate levels of top fall, and compares field curing with forced-air methods. It examines topping, grading, packaging, transportation, storage temperature, relative humidity, ventilation and disease management. Physiological and biochemical changes occurring during storage are also considered. An integrated post-harvest approach combining correct maturity assessment, suitable harvesting, complete curing, careful handling, controlled storage and regular quality monitoring can considerably reduce losses and improve year-round onion availability.

I. FILL UPS

1. _____ is the increased function of any biological quality in a hybrid offspring.
2. Heterosis is otherwise known as _____.
3. _____ is the reduced fitness in a given population as a result of breeding of related individuals.
4. In _____ heterosis type, naturally occurring mutants are sheltered.
5. The progeny posses superiority over parents in vegetative growth, but reduction in yield is known as _____.
   1. Average heterosis is mathematically expressed as _____.

1. HETEROSIS

1.1. Definition

Heterosis or hybrid vigor or outbreeding enhancement, is the increased function of any biological quality in a hybrid offspring. It is the occurrence of a genetically superior offspring from mixing the genes of its parents.

1.2. Inbreeding depression

Inbreeding depression is the reduced fitness in a given population as a result of breeding of related individuals. In general, the higher the genetic variation within a breeding population, the less likely it is to suffer from inbreeding depression.