Review on; Seed Genetic Purity for Quality Seed Production

Production and productivity of the crops are decreasing from time to time due to lack of improved varieties and other management factors. Improved varieties are known for their excellent genetic, physical, and physiological purity. Hybrid seed production is highly contaminated by crossed pollen from another variety or self-pollination. The development of hybrid varieties requires high genetic quality seeds. Quality seeds are efficient to use agricultural inputs such as fertilizers and irrigation to produce the desired quality and amount of seed. The direct contribution of quality seed alone can increase production by 25% wisely combined with other inputs. However, during the seed production process, genetic purity of seed is lost due to developmental variation, mechanical mixtures, natural crossing, genetic drift, the influence of disease, mutations, and adverse climatic conditions. The extent of genetic deterioration is higher in cross-pollinated crops than selfpollinated ones. Yield loss after self-seed production of self-pollinated crops are not serious up to certain generations such that the yield reductions amount to about after one year, 96% after two years, 90% after three years and 83% after nine years, but, in hybrid seed production, it will be null. These problems could be minimized through crop rotation, isolation distance, field inspection, seed certification, and seed legislation by applying genetic purity control techniques (i.e. morphological, chemical and molecular).