Genetic Polymorphism of Wx Gene and Its Correlation with Main Grain Quality Characteristics in Rice

Abstract

The allelic variation of the Wx gene in 50 non-glutinous rice varieties (lines) was analyzed by using the microsatellite marker RM190 [for (CT)_n simple sequence repeat (SSR)] and cleaved amplified polymorphic sequence(CAPS) marker 484/W2R-ACC?[for G/T single nucleotide polymorphism (SNP)]. Six homozygous (CT)_n types, namely (CT)₂₀, (CT)₁₉, (CT)₁₈, (CT)₁₇, (CT)₁₆, (CT)₁₄, (CT)₁₁ and (CT)₁₀, and a heterozygous genotype (CT)₁₁/(CT)₁₈ were detected for RM190, of which (CT)₁₁ and (CT)₁₈ were predominant. Two homozygous Wx genotypes (G/G and T/T) and one heterozygous (G/T) were detected using 484/W2R-ACC?. Most of the materials with a RM190 of (CT)₁₁ were G/G for SNP of 484/W2R-ACC I, while T/T for SNP was predominantly appeared in materials with (CT)₁₈. The materials tested could be grouped into 10 categories using the two markers together. Results indicated that 59.3% variance of amylose content was attributed to the polymorphism of Wx gene revealed by RM190, while 56.1% and 24.6% of the variances in amylose content and gel consistency were respectively to the polymorphism of Wx gene revealed by 484/W2R-ACC I. Furthermore, with both SSR and CAPS markers, 72.4% of the variance in amylose content could be explained. In addition, the application prospects of the two markers in breeding were also discussed.