Effectiveness of early generation direct selection for grain yield in improving yield under drought
2011
Sta. Cruz, Ma.T. | Maturan, P. | De Ocampo, D. | Malabanan, C. | Cuevas, T. | Lucero, O. | Panting, M. | Kumar, A., International Rice Research Inst. , Los Baños, Laguna(Philippines). Plant Breeding, Genetics and Biotechnology
Nearly 30 percent of rice area in the Philippines is rainfed and prone to frequent drought occurrence. Earlier efforts to improve yield under drought concentrated on selection for secondary traits in early generations and testing for yield under drought in advanced stage has not yielded satisfactory yield increase under drought. Early generation selection has been suggested to have more chance to allow favorable alleles to accumulate much faster before the population size has been reduce and while variability is still high allowing yield increase under drought. In the present study, F2 generation selection under drought and irrigated control for grain yield on two populations. N22/2* Swarna and N22/2* Sambha Mahsuri were carried in DS [dry season] 2009. Selected plants were advanced and evaluated for yield potential in 2009 WS [wet season]. Finally, a total of 50 lines selected from each population were evaluated in 2010 DS under both control and drought conditions. Results showed that lines advanced through selection under drought yielded higher under drought with no yield penalty under irrigated control condition. The study indicated effectiveness of early generation selection for grain yield under drought. At IRRI, practicing early generation direct selection for grain yield, several breeding lines with high yield potential and good yield under drought have been developed for lowland drought prone conditions. The efforts has led to release of variety Sahbhagi dhan - IR74371-70-1-1 in India, Tarharra 1-IR80411-49-1-B-B, Sukha dhan 1-IR74371-46-1-1, Sukha dhan 2-IR74371-54-1-1, Sukha dhan 3-IR74371-70-1-1 in Nepal in 2009-2011. These varieties provide 0.8-1.2t/ha yield advantage under drought over the presently grown varieties in these countries.
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