Qtl analysis for flowering time using backcross population between Oryza sativa IR 36 and oryza rufipogon

Recently, climate change are causing serious loss to agricultural production in Vietnam and worldwide. Decreased rice yield due to climate change is needed to consider and solve as soon as possible. Prolonged high temperature at flowering time induced spikelet sterility of rice has been proved in number of studies. Some rice production areas, rice yield were damaged almost entirely. Therefore, study on early flowering time trait of rice to escape high temperature period of the day is the new strategy of this study. To evaluate this useful trait, the wild rice Oryza rufipogon W 630 and Oryza sativa IR36 wereused as materialsofthe study. As for SOT, two parameters of SOTb (beginning time when the first spikelet opens) and SOTm (median time when 50% of the spikelets open) were recorded. One QTL located on chromosome 8 in the regions of RM44-RM223 was detected for SOTb and another one QTL located on chromosomes 5 in the regions of RM13-RM574 was detected for SOTm, respectively. In addition, the additive effect of single wild alleles at these alleles was 0.27h and 0.25h. The results indicate that the homozygous wild alleles at these loci have potential to promote earlier flowering.