QTL Mapping, Epistasis and Environmental Effects Analysis for Rice Chalkiness Trait
- 生命科学－已发表论文 
水稻的垩白性状是当前限制中国稻米品质提升的最主要因素.研究垩白形成机理及遗传特性,将有利于提高育种中垩白性状的改良效率.本课题组先前构建了广陆矮; 4号/佳辐占重组自交系(GJ RIL)及遗传图谱.本研究连续2年在上杭县和龙海市两地共种植6季GJ; RILs,据各季垩白性状表型数据进行遗传分析,结合遗传图谱进行QTL定位、上位性分析和环境效应分析.遗传分析发现垩白粒率和垩白度呈偏态分布,推测; 垩白性状受主效基因与微效基因共同影响.QTL定位中,垩白粒率获得3个QTLs,qPGWC2、qPGWC4和qPGWC5,遗传贡献率分别为2.84; %、3.74%和14.09%;垩白度获得3个QTLs,qDEC1、qDEC4和qDEC5,遗传贡献率分别为2.96%、4.88%和7.79%.上; 位性分析中,垩白粒率和垩白度分别获得7对和5对上位性QTLs,贡献率为0.23%~3.55%.RM307~RM518区间内同时检测到垩白粒率和垩; 白度的QTLs,并参与了垩白粒率和垩白度的上位性互作.RM598~RM5140区间内也同时检测到垩白粒率和垩白度的QTLs,也参与了垩白度的上位; 性互作.环境效应分析发现,垩白度的3个QTLs及~eqDEC10和~eqDEC9这对上位性QTLs均与2010年早季龙海种植环境发生显著或极显著; 的互作效应.Rice (Oryza sativa L.) chalkiness is the most important limiting factor; for currently improving rice quality in China. Studying rice chalky; formation mechanism and hereditary character will be helpful for; increasing the efficiency of the improvement of chalky quality in; breeding. A Guanglu'ai No.4/Jiafuzhan recombinant inbred line(GJ RIL); was developed and its genetic map was constructed previously by our; research group. In this study, the genetic analysis of rice chalkiness; was carried out basing on the chalky phenotyping data of GJ RIL from a; total of 6 growth seasons of two different locations, Shanghang county; and Longhai city, in two consecutive years. Then the QTL mapping,; epistasis and environmental effects of chalkiness were studied by using; these phenotying data and the genetic map. The genetic analysis; indicated that percentage of grains with chalkiness (PGWC) and degree of; endosperm chalkiness (DEC) showed skewness distribution, suggesting that; chalkiness trait was affected by both major and minor genes together. In; QTL mapping, three PGWC QTLs, qPGWC2, qPGWC4 and qPGWC5, were detected,; which explained 2.84%, 3.74% and 14.09% of the genetic variation,; respectively. Three DEC QTLs, qDECl, qDEC4 and qDEC5, were mapped, which; explained 2.96%, 4.88% and 7.79% of the genetic variation, respectively.; In QTL epistasis analysis, 7 and 5 pairs of epistasis QTLs for PGWC and; DEC were identified respectively, and their contribution rates ranged; from 0.23% to 3.55%. The RM307~RM518 interval harbored the PGWC and DEC; QTLs, which were involved in epistatic interaction of PGWC and DEC; respectively. The RM598~RM5140 interval also harbored the PGWC and DEC; QTLs, which also participated in epistatic interaction of DEC.; Environmental effect analysis showed the three DEC QTLs (qDECl, qDEC4; and qDEC5) and a pair of epistatic QTLs between ~eqDEC10 and ~eqDEC9 all; exhibited significant or very closely significant interaction effects; under the environmental conditions in early season at Longhai city of; Fujian province in 2010.