玉米叶绿素含量的QTL定位

QTL mapping for chlorophyll content in maize

为了探讨玉米叶绿素含量的遗传规律，以Al50—3．2×Mo17杂交组配的189个F2单株作为作图群体，构建了具有112个标记位点的玉米分子遗传图谱，于喇叭口期和开花期分别进行了玉米叶绿素a含量（chla），叶绿素b含量（chlb），其他叶绿素含量（chic）和叶绿素总含量（chlz）4个性状的测定，并进行QTL分析。在喇叭口期和开花期共检测到32个QTL，分布在除第6和10染色体以外的其他染色体上。在喇叭口期检测到24个QTL，分布于第1、2、3、5、7、8和9染色体上，叶绿素a、叶绿素b、其他叶绿素和叶绿素总含量各检测到6个QTL，在同一区间内检测到的4个性状的QTL之间的距离在0～2cM之间。喇叭口期检测到控制叶绿素a、叶绿素b、其他叶绿素和叶绿素总含量的4个主效QTL位于第5染色体上的umc1098～bnlg557区间，分别可解释表型变异的11．63％、10．3％、10.77％和11.51％。开花期检测到8个QTL，分布于第4和5染色体上。其中叶绿素a、叶绿素b、其他叶绿素和叶绿素总含量各2个QTL。标记umc1098和bnlg557之间同时存在控制喇叭口期4个叶绿素含量性状的QTL和开花期控制叶绿素a和叶绿素b的QTL。标记umc2308和bnlg386之间只存在控制开花期4个叶绿素含量性状的QTL。

In order to explore the genetic basis for chlorophyll content in maize （Zea mays L.）, a total of 189 F2 individuals derived from the single cross between the inbred lines Al50-3-2 and Mo17 were used as mapping population. Four traits associated with chlorophyll content were measured at the trumpet stage and at the flowering stage. Total 32 QTLs were investigated on all the chromosomes except for chromosomes 6 and 10. There were 24 QTLs located on chromosomes 1, 2, 3, 5, 7, 8, and 9 at the trumpet stage. Six QTLs were investigated for chlorophyll-a content （chla）, chlorophyll-b content （chlb）, other chlorophyll content （chic）, and total chlorophyll content （chlz）, respectively. QTLs for four traits were located in the same marker intervals in many cases. The distance among different QTLs of the four traits in the same marker intervals ranged from 0 to 2 cM. The four major QTLs for chla, chlb, chic, and chlz at the trumpet stage, which explained 11.63%, 10.3%, 10.77%, and 11.51% of the phenotypic variance, respectively, were investigated between umc1098 and bnlg557 on chromosome 5. There were 8 QTLs located on chromosomes 4 and 5 at the flowering stage, with 2 QTLs for chla, chlb, chic, and chlz, respectively. QTLs were investigated between umc1098 and bnlg557, which controlled the four chlorophyll content gaits （chla, chlb, chic, and chlz）, at the trumpet stage and two chlorophyll content traits （chla and chlb） at the flowering stage. QTLs between umc2308 and bnlg386 for the four traits related to chlorophyll content were investigated only at the flowering stage.