云南软米低直链淀粉含量及其相关性状遗传分析

Genetic Analysis of Low Amylose Content and Its Related Traits of Soft Rice Variety from Yunnan

IR36×八宝米F2 单株直链淀粉含量与农艺、米粒外观性状相关性及其遗传分析表明 ,18个性状有 9个性状与直链淀粉含量呈极显著 (P <0 0 1)或显著 (P <0 0 5 )相关性 ,尤其直链淀粉含量与垩白长 ( 0 35 3 )、株高 ( - 0 2 4 2 )、结实率( 0 2 35 )、第一节间长 ( 0 195 )的相关系数达极显著水平 (P <0 0 1) ,直链淀粉含量 9%～ 15 %是籼型软米杂种后代的重要指标 ;八宝米的垩白长和第一节间长均表现部分显性主效基因 ,籼型八宝米低直链淀粉基因和IR36的矮秆基因均为 1对隐性主效基因控制 ,表明八宝米的优质基因易于转育或表达 ,可广泛用于水稻优质米育种 ;用SSR标记将软米基因有关的低直链淀粉含量定位于第 6染色体上与RM 190连锁 ,其遗传距离为 18 8cM。

Genetic analysis of low amylose content and agronomical and external traits was conducted using brown rice IR36/Babaomi F 2 segregation population. The results showed that the amylose content of grains controlled by a major gene was very significantly correlated with 9 characters, especially the chalky length (0 353 ** ), plant height (-0 242 ** ), seed setting rate (0 235 ** ), the first internode length (0 195 ** ). Amylose content of 9 1%～15 0% is an important index of hybrid progenies of soft rice for indica . The chalky length and the first internode length of Babaomi are controlled by major genes with partial dominance. Low amylose content from Babaomi and dwarf gene from IR36 are controlled by one recessive major gene. Therefore, it is easier for high quality gene from Babaomi to be used in quality breeding of rice. Low amylose content related to soft rice in Babaomi was located the chromosome 6, which is loosely linked to RM190, with genetic distance of 18 8 cM.