水稻粒型染色体片段代换系Z8的QTL定位与次级代换系选育  

QTL Mapping of Important Agronomic Traits and Breeding of Secondary Substitution Lines of CSSL-Z8 in Rice

作　　者：毛祖元 陈倩[1] 邸新晏 陈梅[1] 王晓菲 赵芳明[1] 凌英华[1] MAO Zuyuan;CHEN Qian;DI Xinyan;CHEN Mei;WANG Xiaofei;ZHAO Fangming;LING Yinghua(Rice Research Institute,Southwest University/Chongqing Key Laboratory of Transgenic Plans and Safety Control,Chongqing 400715,China)

机构地区：[1]西南大学水稻研究所/转基因植物与安全控制重庆市重点实验室,重庆400715

出　　处：《西南大学学报（自然科学版）》2023年第1期45-54,共10页Journal of Southwest University(Natural Science Edition)

基　　金：重庆英才计划“包干制”项目(cstc2022ycjh-bgzxm0134);西南大学大学生创新创业训练计划项目(S202210635248).

摘　　要：粒型是水稻重要的农艺性状,由多个基因调控,属于典型的数量性状,与产量密切相关.染色体片段代换系(Chromosomal Segment Substitution Line,CSSL)是研究数量性状的良好材料,能够将复杂的数量性状转化成单个的遗传因子,从而有效分离主效数量性状基因座(Quantitative trait locus,QTL)或关键基因,并准确估算其遗传效应.以粳稻日本晴(Nipponbare)为受体,优良恢复系R225为供体构建的CSSL群体中鉴定到1个水稻长宽粒代换系Z8,其携带14个来自供体亲本R225的染色体片段,平均代换长度8.41 Mb.与受体亲本日本晴相比,Z8的粒长、粒宽、长宽比、株高、一次枝梗数、二次枝梗数、千粒质量、着粒密度和每穗总粒数等性状均增加(p<0.01或p<0.05),有效穗数、穗长和结实率均降低(p<0.01),而每穗实粒数和单株产量的差异无统计学意义.扫描电镜检测表明,Z8籽粒外颖壳表皮细胞长度、宽度分别增加了33.14μm和5.20μm(p<0.01),而单位面积细胞数目则减少了3.4个(p<0.01),表明Z8籽粒变宽、变长可能是由于籽粒外颖壳细胞纵向和横向增大所致.利用日本晴/Z8构建的次级F2分离群体对粒长、粒宽等10个农艺性状进行QTL定位,共鉴定到33个QTLs,其中粒长、粒宽和长宽比各6个,千粒质量4个,株高和穗长各3个,每穗实粒数2个,一次枝梗数、二次枝梗数与结实率各1个,贡献率在2.04%~88.67%之间.结合QTL定位与分子标记辅助选择(MAS),从F3家系中鉴定到2个含目标性状QTL的双片段代换系,4个三片段代换系,3个四片段代换系,14个五片段及以上代换系.目标性状的QTL定位以及次级代换片段的成功选育,为进一步研究目标性状的遗传机理提供了良好的理论参考和材料支撑.Grain type is an important agronomic trait of rice,which is regulated by multiple genes,exhibiting typical quantitative traits features and closely related to the yield performance of rice varieties.Chromosomal segment substitution line(CSSL)is ideal material for the dissection of quantitative traits,through which the inheritance of complex quantitative traits could be disintegrated into patterns with single QTL or major gene under purified genetic background.In the present study,an elite chromosomal segment substitution line of Z8(CSSL-Z8)in rice with increased grain length and width was screened out from the CSSL library constructed by the cross of Nipponbare(receptor)and restorer line R225(donor).Results of molecular characterization showed that CSSL-Z8 contained 14 introduced chromosomal segments from R225,with an average length of 8.41 Mb.Compared with Nipponbare,CSSL-Z8 possessed statistically increased grain length,grain width,ratio of grain length/width,plant height,number of primary and secondary branches,1000-grain weight,seed density,and total grains per panicle(p<0.05 or p<0.01).The effective panicle number,panicle length,and seed setting rate of CSSL-Z8 decreased significantly(p<0.01).There no statistical differences were observed for the number of grains per panicle and yield per plant between Nipponbare and CSSL-Z8.The results of scanning electron microscopy showed that the cell length and width of outer glume of CSSL-Z8 increased by 33.14μm and 5.20μm(p<0.01),respectively,while the cell number of outer glume of CSSL-Z8 decreased by 3.4(p<0.01),indicating that the increased grain length and width of CSSL-Z8 might be caused by the longitudinal and lateral enlargement of outer glume cells.QTLs for 10 agronomic traits,including grain length and width,were identified through the F2 population constructed by Nipponbare/CSSL-Z8.A total of 33 QTLs were identified,i.e.,six for each of grain length,width,and ratio of grain length/width,four for 1000-grain weight,three for both of plant height and panicle

关 键 词：水稻 粒型 染色体片段代换系 QTL定位 次级代换系 

分 类 号：S511[农业科学—作物学]