Plant Genetic Resource or Germplasm related to Plant Breeding

Plant Genetic Resource

1. Topic on Plant Genetic Resources By Dr. Chitralekha Shyam Genetics and Plant Breeding

2. Content Definition and features of PGR Kinds of PGR Classification of gene pool system Activities of PGR

3. Definition and features Definition: The sum total of genes in a crop species. Or A whole library of different alleles of a species . The basic material with which a plant breeder has to initiate his breeding programme . Features: Represent the entire genetic variability in a crop species. Includes both cultivated, wild sp. or relatives of crop plant. 3. Consists of land races, modern cultivars, obsolete cultivar s, breeding stocks, wild forms and wild relatives of cultivated crops. 4. It is collected from the centers of diversity, gene bank, gene sanctuary, farmers field, markets and seed companies. 5.The basic material for launching a crop improvement programme. 6.May be indigenous or exotic.

4. Kinds of PGR Land races Obsolete cultivar Modern cultivar Advanced breeding line Wild form Wild relative Mutant

5. 1. Land races: They are primitive cultivars which were selected and cultivated by the farmers for many generations. It have broad genetic base. 2. Obsolete Cultivar: Improved varieties of recent past. Example: Wheat variety K68, K65 and Pb 591 with tall variety 3. Modern Cultivar: The currently cultivated high yielding varieties. 4. Advanced breeding lines: Pre-released plants which have been developed by plant breeders for use in modern scientific plant breeding. 5. Wild forms of cultivated species: Wild forms of cultivated species. 6. Wild relatives: Those naturally occurring plant species which have common ancestry with crops. 7. Mutant : A mutant is an organism/ plant having a new genetic character arising from an instance of mutation. Example: Dee-Geo-Woo-Gen in Rice and Norin 10 in Wheat

6. Classification of Gene pool system This system is given by Harlan and Dewet 1971 . Primary gene pool: Intermating is easy and leads to production of fertile hybrids. It includes plants of the same species. Secondary gene pool: The material that leads to partial fertility on crossing with GP1. It includes related plant species. Tertiary gene pool: The genetic material which leads to production of sterile hybrids on crossing with GP1.

7. Activities of Germplasm Exploration and collection Conservation Evaluation Documentation Distribution Utilisation

8. Exploration and Collection 1.Source of collection: Center of diversity, Gene bank, Gene sanctuaries, Seed companies and Farmers 2.Priority of collection : Endangered species 3.Agencies of collection: Crop Research Institutes and State Agricultural Universities with NBPGR and IPGRI 4.Method of collection : Region of genetic diversity, personal visit to gene bank center and exchange of material 5.Method of sampling : Random sampling and Biased sampling. Both are important. 6.Sample size: 50 to 100 individuals per site with 50 seeds per plant

9. Conservation 1.In-situ conservation: Under natural habitat It requires biosphere reserves, national parks or protection of endangered species . 2.Ex-situ Conservation : P reservation of germplasm in gene bank Conservation in the form of seed or meristem cultures.

10. Evaluation In respect of morphological, genetical, economic, biochemical, physiological, pathological and entomological traits Specialist from the disciplines of plant breeding, physiology, biochemistry, pathology and entomology This task is completed by a team of experts from IPGRI . Evaluation in 3 different places In the field In green house In the laboratory

11. Documentation Documentation: Refers to compilation, analysis, classification, storage and dissemination of information . Provide information about various activities of plant genetic resources Latest information

12. Distribution Responsibility of the gene bank Supplied to the workers who are as a research worker Supplied free of cost Quantity of seed samples to be sent is usually small and depend on availablity of seed materials

13. Utilization In crop improvement: 1 Cultivated germplasm: can be used as a variety, as a parent and as a variant 2 Wild germplasm: As a donar for transfer of biotic and abiotic resistance gene