大豆品种北农103早花性状的遗传解析

Genetic Dissection of Early-Flowering Trait in Soybean (Glycine max L.) Cultivar BeiNong103

为明确大豆品种北农103的早花性状的遗传特性,以北农103为父本和晚花品种海系13为母本,构建了F2分离群体和F5重组自交系群体。通过F2分离群体研究其早花性状的遗传方式,利用极端性状混池重测序结合分子标记加密方法定位早花性状基因,并对候选基因进行序列分析。结果显示,北农103的早花性状主要由1对隐性基因控制。该基因位于6号染色体(C2)上,在Satt557和XH211标记之间,遗传距离均为1.0 c M。基因序列分析表明,该基因为已知的E1的等位隐性基因el,DNA序列中第218位碱基由E1中的G变为C,导致核苷酸由精氨酸(AGG)变为苏氨酸(ACG),由于北农103的e1基因中单个碱基变异导致光周期的敏感性发生了改变,产生早开花现象。经系谱分析推测,北农103中的e1基因来源于美国品种Century,可在改良大豆品种的成熟期和株高方面发挥作用。

To clarify the genetic factor underlying the early flowering in soybean(Glycine max L.)cultivar Bei Nong103,F2 segregating population from a cross of cv.Bei Nong103(male)and cv.Haixi13(female,lateflowering)as well as its derived F5 recombine inbred line population were subjected for analyzing the segregation ratio and the preliminary mapping following the bulked-segregant analysis pipeline.The genetic analysis suggested a single recessively-inherited locus on chromosome 6,which is associated to the early-flowering phenotype in cv.Bei Nong103.The genetic interval,franked by two markers Satt557 and XH211,expanded 2 c M which harbors a formerly-identified recessive gene el of E1.The sequence analysis showed a G to C mutation at the 218 bp of E1 coding sequence,thus resulting in an amino acid substitution of arginine(AGG)to threonine(ACG)in Bei Nong103.Taken together,the single-base mutation of e1 might be the causal agent that underlies the sensitivity of the photoperiod and the early flowering.The elite allele,suggested by the pedigree analysis,is derived from the American variety Century,and might play a role in future improvement of the maturity and plant height characteristics of cultivar in soybean breeding.