小麦TaCKOX4基因变异与旗叶叶绿素含量相关性分析

Reletionship between Allelic Variation of TaCKOX4 Gene and Chlorophyll Content of Flag Leaf in Common Wheat

本文以京411/红忙春21构建的重组自交系群体(RILs)为研究材料,通过对小麦抽穗期、盛花期和灌浆期旗叶叶绿素含量分布频率的分析,得出叶绿素含量在花后7d以前多呈正态分布,而灌浆中后期呈偏态分布或双峰分布,说明前者为受多基因控制的数量性状,而后者存在与其相关的主效基因。在多个生长发育时期中,旗叶叶绿素含量呈现先上升后下降的趋势,在盛花期达到最大值,花后24d,叶绿素含量则急剧下降,成熟时接近为0。在RILs群体中对小麦细胞分裂素氧化酶基因等位变异进行鉴定,得出TaCKOX4基因在群体中表现较好的多态性,其变异与小麦旗叶多个生长发育时期(如抽穗期,盛花期及灌浆期)叶绿素含量呈显著或极显著相关,且具有A带型家系的叶绿素含量显著高于B带型家系的叶绿素含量,说明TaCKOX4基因变异与小麦旗叶叶绿素含量关系密切。

The c ontent o f flag leaf at the stages of heading, flowering and filling was determined in a RILs population from the cross between Jing411 and Hongmangchtm21. The results indicated that the chlorophyllcontent of RILs showed an approximate normal distribution before the stages of 7 day after flowering （DAF）, which might be a quantitative locus conferring the trait. However, at the middle to later stages of grain filling, thechlorophyll content of flag leaf had a bimodal distribution or skewed distribution, which might be controlled by a major locus. The chlorophyll content of flag leaf showed a rising trend before the flowering stages and then startedto descend, which had a great degradation at 24 DAF and approaching to zero at the maturation stage of grain. In this study we also detected the allelic variation of cytokinins oxidase genes （CKOX） in the population, the resultsshowed that the TaCKOX4 gene carried a good polymorphisms, which the allelic variation had an significant correlation with chlorophyll content of flag leaf at the levels of 0.05 and 0.01. The chlorophyll content of flag leafof lines carrying A-type allele of TaCKOX4 was significantly higher than that of B allele at these stages. These results could confirm a close association between the allelic variation of TaCKOX4 and the chlorophyll content offlag leaf in common wheat.