小麦旗叶宽主效QTLQFlw-5B遗传效应解析

Genetic Analysis of a Major Stable QTL QFlw-5B for Wheat Flag Leaf Width

为了明确位于小麦5B染色体上的一个旗叶宽主效QTL QFlw-5B的遗传效应,对5B染色体进一步加密,从而缩小靶区段的范围,在加密图谱的基础上,利用衍生自科农9204×京411的188个重组自交系群体(KJ-RIL),对8个环境下旗叶宽做进一步的定位分析,将QFlw-5B定位于AX-110978403~AX-111671812的61.22~68.60 cM遗传距离范围内,能够解释9.40%~19.76%的旗叶宽表型变异,来自科农9204的等位基因增加旗叶宽0.04~0.07 cm。利用与QFlw-5B紧密连锁标记AX-108884656对188个KJ-RIL家系进行遗传分析,结果表明,QFlw-5B优异等位基因在8个环境下均能增加穗粒数,在6个环境下能增加千粒重和单株产量,而对单株穗数有一定的负效应。利用310份育成品种(系)对QFlw-5B优异单倍型的应用情况进行分析,结果表明,QFlw-5B优异单倍型虽然已经被育种家选择,但还有较大的遗传改良空间。

In order to determine the genetic effect of a flag leaf width major effect QTL QFlw-5B on wheat chromosome 5B,chromosome 5B was further enriched to narrow the range of the target region.Based on the increased density map,the 188 KJ-RILs population derived from a cross between Kenong 9204 and Jing 411 in eight different environments were used for QTL mapping,and QFlw-5B was mapped between AX-110978403 and AX-111671812 with the genetic distance from 61.22 cM to 68.60 cM,which explained 9.40%to 19.76%of the phenotypic variation.The alleles from Kenong 9204 increased flag leaf width(FLW)with 0.04-0.07 cm.AX-10884656,a molecular marker closed linkage with QFlw-5B,was used for genetic analysis in the 188 KJ-RIL families,and the results showed that excellent alleles of QFlw-5B increased kernel number per spike(KNPS)in the eight environments.Meanwhile,it increased thousand-kernel weight(TKW)and grain yield per plant(GYPP)in the six environments,while it had negative effect on spike number per plant(SNPP).The application of QFlw-5B haplotype was analyzed with 310 bred varieties(lines),and the results showed that the excellent haplotype of QFlw-5B has been utilized in wheat breeding programs,while there was still great potential in genetic improvement of wheat.