玉米单倍体诱导败育数量性状位点定位及全基因组选择

QTL Localization and Genome-wide Selection Analysis of Kernel Abortion Caused by Haploid Induction in Maize

对玉米单倍体诱导败育的遗传分析,降低籽粒败育程度,增加玉米植株果穗结实籽粒数,使其能够减少败育率的同时产生更多数量具有利用价值的单倍体籽粒,加快玉米双单倍体育种技术进程。选用生物诱导情况下表型性状显著差异的玉米自交系B73和郑58为亲本材料进行杂交构建F_(2∶3)群体,采用液相48k探针捕获技术进行基因型检测,对玉米生物诱导F_(2∶3)群体孤雌生殖单倍体产生过程中的胚败育率、胚乳败育率进行数量性状位点(QTL)定位和全基因组选择。结果表明,胚败育率、胚乳败育率受到环境、基因型和环境与基因型互作的影响极显著,遗传力分别为0.49、0.44。基于3个不同环境下对胚败育率进行QTL定位,共检测到了8个控制胚败育率的QTL分别位于1、2、7、9、10号染色体上,定位到1个主效QTL位点,能够解释胚败育率表型变异的10.20%。共检测到了控制胚乳败育率的11个QTL,其中有2个主效QTL分别解释了胚乳败育率表型变异的11.15%、11.63%。胚败育率和胚乳败育率共同定位到了一个位于2号染色体上的位点,属于一因多效位点。胚败育率、胚乳败育率全基因组选择结果表明,当训练群体占总群体80%、90%时,预测精度较高。

The genetic analysis of haploid-induced defeat in maize was conducted to reduce the degree of seed defeat,increase the number of fruiting seeds on the ears of maize plants,and enable them to reduce the defeat rate while producing a greater number of utilizable haploid seeds to speed up the breeding process of maize haploid DH lines.In this experiment,maize selfed lines B73 and Zheng 58,which differed significantly in phenotypic traits under biologically induced conditions,were used as the parents to cross the F_(2∶3) population,and the genotype was detected by liquid-phase 48k probe capture technique.The results showed that embryo septicity and endosperm septicity were significantly affected by environment,genotype and environment-genotype interactions,with heritabilities of 0.49 and 0.44,respectively.Eight QTLs controlling embryo septicity were detected on chromosomes 1,2,7,9 and 10 based on QTL localization in three different environments,and one master QTL locus was identified,which could explain the phenotype of embryo septicity.A total of eight QTL controlling embryo abortion rate were detected on chromosome 1,7,9 and 10,and one main effect QTL locus was identified,which could explain 10.20%of the phenotypic variation in embryo abortion rate.A total of 11 QTL were detected to control endosperm defeat rate,and two of them explained 11.15%and 11.63%of the phenotypic variation in endosperm defeat rate,respectively.Embryo septicity and endosperm septicity were jointly localized to a locus on chromosome 2,which was a one-causal multi-effect locus.The results of genome-wide selection for embryo abortion rate and endosperm abortion rate showed that the prediction accuracy was high when the training population accounted for 80%and 90%of the total population.