基于双单倍体群体的玉米株高和穗位高QTL分析

QTL analysis of plant and ear height by using DH population in maize

为了进一步探明玉米株高和穗位高的遗传基础,利用郑单958为基础材料构建的包含161个双单倍体(Doubled haploid,DH)的群体,分别在长葛、淇县进行田间试验,采用复合区间作图法对植株性状进行数量性状位点(Quantitative trait locus,QTL)分析。分别检测到7,11和6个株高、穗位高以及穗位系数(穗位高/株高)QTLs,贡献率变幅分别为6.77%~21.31%,5.09%~17.12%和6.89%~17.78%,其中qph-3-3,qph-2-10,qeh-5-9以及qeh/qph-3-1为主效QTLs;株高和穗位高有4对共同标记区间的QTLs,穗位系数与穗位高有3对共同标记区间的QTLs,一定程度上揭示了株高和穗位高的遗传相关性;株高和穗位高的广义遗传力高达88.52%和93.78%,表明株高和穗位高遗传稳定性强,受环境影响较小,是早代选择的重要株型指标。

In order to study the genetic mechanism of corn plant height and ear height, field experiments were carried out in Changge City and Qixian County using a mapping population consisting of 161 DH lines from the cross Zhengdan 958 and some plant traits were investigated. QTL mapping and analysis for plant height,ear height and coefficient of ear height（ ear height / plant height） were conducted under the two environments by composite interval mapping method. Seven,eleven and six QTLs were detected for plant height,ear height and coefficient of ear height,and the variance range of phenotypic variation explained were 6. 77% ~ 21. 31%,5. 09% ~ 17. 12% and 6. 89% ~ 17. 78%,respectively. Among the 24 QTLs detected,qph-3-3,qph-2-10,qeh-5-9 as well as qeh / qph-3-1 were major QTLs. Four same QTLs were detected for plant height and ear height,while three QTLs for coefficient of ear height and ear height were mapped in the same marker interval,which revealed the genetic relationship between plant height and ear height. The broad sense heritability（ H_B^2） of plant height and ear height reached 88. 52% and 93. 78%,respectively,which demonstrated plant height and ear height had stable inheritability and was less affected by environment. So plant height and ear height can be used as important select index for plant type in early generation.