水稻发芽期和芽期耐冷性QTL定位

QTL analysis of rice cold tolerance at germination and bud stage

由耐冷品种空育131为母本、冷敏品种小白粳子为父本构建含有195个株系的重组自交系群体为材料,以发芽期相对发芽率、发芽势、平均发芽天数、发芽系数及芽期成苗率和耐冷级别为鉴定指标,结合527个Bin标记,使用QTL Icimapping 4.2进行水稻发芽期和芽期耐冷性QTL定位。结果表明,检测到7个与发芽期耐冷性相关QTL位点,分别位于第1、2、3、6、7、11号染色体上,表型贡献率为4.25(_(q)AGD2)~8.30(_(q)RGR3)。检测到3个与芽期耐冷性相关QTL位点,位于第3、7号染色体上,表型贡献率为5.82%(_(q)CTL3)~8.38%(_(q)SSR7),其中qSSR7在成苗率和耐冷级别两指标均被检测到。此外,还检测到4对上位性位点,其中1对与发芽期耐冷性相关,表型贡献率为14.26%,另有3对与芽期耐冷性相关,表型贡献率分别为4.52%~17.04%。研究为寒地粳稻耐冷遗传基础解析提供参考。

A recombinant inbred line population was chosen as experimental materials which contained 195 lines and derived from the cross between Kongyu 131 and Xiaobaijingzi.Kongyu 131 was cold tolerant and was used as female parent.Xiaobaijingzi was a cold sensitive variety and was chosen as the male parent.Four germination stage characters(relative germination rate,germination energy,average germination days and germination coefficient)and two bud stage characters(survival seeding rate and cold tolerance level)were selected as identification indices.QTL Icimapping 4.2 was used to map QTLs between phenotype and 527 Bin markers.The results showed that seven QTLs related to cold tolerance at germination stage were mapped on chromosome 1,2,3,6,7 and 11,respectively,and their phenotypic contribution rate ranged from 4.25(_(q)AGD2)to 8.30(_(q)RGR3).Three QTLs related to cold tolerance at bud stage were located on chromosome 3 and 7,respectively,and their phenotypic contribution rate ranged from 5.82(_(q)CTL3)to 8.38(_(q)SSR7).In addition,four pairs of epistatic loci were detected.One pair were related to cold tolerance at germination stage and their phenotypic contribution rate was 14.26%;the other three pairs were related to cold tolerance at bud stage and their phenotypic contribution rate ranged from 4.52%to 17.04%.The study provides a genetic reference which analyze the cold tolerance of japonica rice in cold region.