Abstract: QTL sites controlling the concentrations of Na⁺ and K⁺ in the upper ground of rice seedlings were detected under salt and alkaline stress conditions to provide a theoretical basis for further research on salt tolerance, alkaline tolerance genetic mechanism and molecular marker assisted breeding of rice. A group of 200 recombinant autogenous lines was derived from Xiaobaijingzi/Kongyu 131 and its genetic linkage map containing 142 SSR marks to analyze the QTL of score of salt and alkali toxicity, Na⁺ concentration, K⁺ concentration and Na⁺/ K⁺ in rice seedling stage under salt and alkaline stress. A total of 15 QTLs were detected under two conditions, seven and eight QTLs were detected under salt and alkaline stress, distributed on chromosomes 2, 3, 5, 7, 8, 9, 11 and 12, LOD values range from 2.52 to 6.59, and phenotype contribution rate ranges from 6.10% to 28.00%. Among them, qSSNC3 associated with Na⁺ concentration under salt stress and qASNK3 associated with Na⁺/ K⁺ under alkaline stress were located in adjacent intervals; qSSNK2 associated with Na⁺/K⁺ under salt stress and qASKC2 associated with K⁺ concentration under alkaline stress were located in the same interval; qSAT8 and qASNC8 related to Na⁺ concentration and qASKC8 related to K⁺ concentration were located in the same or adjacent interval under alkaline stress. The results showed that Na⁺ and K⁺ concentrations had some genetic overlap under two stress conditions. The results of this study were compared with those of previous studies by the same marker or comparative map,13 QTLs were found to be known as QTLs, while qSAT8 and qASNC8, located between RM547-RM22750, were the new QTL sites.

Key words: Rice, QTL, Salt and alkaline stress, Na⁺, K⁺

CLC Number: 

• S511.03