QTL analysis of dehydration tolerance at seedling stage in rice (Oryza sativa L..)

Dehydration tolerant QTLs at the seedling stage in rice (Oryza sativa L.) was studied using green shoot length as a parameter, which was measured during the recovery period after dehydration stress. According to the results of pilot experiment carried out to evaluate the two parental rice cultivars for the level of dehydration tolerance, at 4 - day and 5-day dehydration stress, Japonica parent Hyogokithanishiki (HGKN) showed more tolerance than that of Hokuriku-142 Indica parent (HOK). Quantitative trait loci (QTLs) associated with dehydration tolerance was identified using 163 recombinant inbred lines derived from these parents on a linkage map constructed with 95 simple sequence repeat (SSR) markers. Three dehydration tolerant minor QTLs were identified on chromosome 1, 2 and 3 at composite interval mapping by WinQTLCARTOGRAHER. According to the additive effect plots the QTLs on chromosome 1 and 2 have the allelic effect from the Indica parent Hokuriku-142 and QTL on chro- mosome 3 has allelic effect from Hyogokithanishiki Japonica parent. However, according to the 1000 time permutation test, these QTLs didn’t exceed the threshold LOD value. Tropical Agricultural Research and Extension 15(4): 2012: page 98-104