云南地方稻种Wx基因第一内含子供体+1位碱基变异与直链淀粉含量的关系

Relationship Between the First Base of Splice Donor of Wx Gene Intron 1 and Amylose Content in Yunnan Indigenous Rice Varieties

应用PCR一步法对来自云南省14个地州、55个市／县的220个籼、梗地方稻种Wx基因第一内含子供体＋1位碱基G／T进行了检测，同时用PCR—AccI酶切法对其中的101份进行验证，结果表明两种方法检测结果一致。根据G／T碱基将220个供试材料分为GG、TT两种基因型。云南地方稻种以GG型占优势，有164个，占74．5％;TT型有56个，占25．5％；籼稻中80．5％属GG型，粳稻中67．0％属GG型。GG型直链淀粉含量较高，平均18．97％，TT型较低，均低于16％，GG、TT基因型之间的平均直链淀粉含量差异极显著。G／T与直链淀粉含量存在密切的联系，其相关系数为0．733＊＊。GG型品种中有33个直链淀粉含量较低（3．91％～15．93％），多数为来源于云南西南部傣族地区的品种。籼稻中的GG型或TT型品种与粳稻中的GG型或TT型品种间平均直链淀粉含量无显著差异，表明GG／TT基因型在籼粳不同遗传背景下直链淀粉表达无显著差异。

There is a single nucleotide polymorphism, G or T, at the first base of splice donor site of Wx gene intron 1. A one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties Of Yunnan Province, of which 101 varieties were validated by PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG genotype, while the other 56 were TT genotype, accounting for 74.5% and 25.5 % of all the varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indies rice and 67.0% of japonica rice showed GG genotype. The rice varieties with GG genotype had significantly higher amylose content （mean 18.97 %） than those with TT genotype （all below 16%）, though 33 rice varieties with GG genotype still had low amylose content ranging from 3.91% to 15.93 %, but most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, indicating that different genetic background, indica or japonica, had no effect on amylose content. The coefficient of correlation between genotype and amylose content was 0. 733 （P〈0.01）.