大白菜紫心性状的遗传分析及度量参数比较

Genetic Analysis and Measurement Parameter Comparison of the Purple Trait in Purple Heading Chinese Cabbage

以紫心大白菜自交系’14S838’为母本,普通大白菜自交系’15S1080’为父本,构建F1、F2群体,研究大白菜紫心性状的遗传规律。结果表明:在F1群体中,大白菜球心颜色均为紫色,但紫心面积均比紫心亲本’14S838’小;在F2群体中,紫心单株与非紫心单株符合3:1的分离比例,说明紫心大白菜的紫色有无是质量性状,叶球紫心对非紫心符合单基因显性遗传模式。采用紫高比(紫心高度/叶球高度)、紫宽比(紫心宽度/叶球宽度)和紫心面积比(紫心面积/叶球面积)作为度量参数来描述紫心大小性状,对F2群体紫心单株进行测定分析,发现这3个参数的广义遗传率分别为94.00%、87.72%和83.33%,说明紫心大小的变异主要受遗传因子的控制,受环境影响较小。次数分布直方图显示紫高比和紫宽比符合正态分布特点,紫心面积比表现为正偏态分布,说明紫心大小为数量性状。进一步分析发现紫高比、紫宽比与紫心面积比之间具有很高的相关性。从测量角度来看,紫心面积比的测量虽然准确但比较繁琐;而紫高比的测量比较简单,并具有遗传力高及其与紫心面积比相关性高的特点。因此,可利用紫高比代替紫心面积比来定义紫心大小这一性状。

Purple heading Chinese cabbage inbred line‘14 S838’and common Chinese cabbage inbred line’15 S1080’were used as male parent and female parent,respectively,and F1 and F2 populations were constructed to study the genetic law of purple heading trait in Chinese cabbage.The results showed that the inner leaves of leaf-head were purple in F1 population,but the purple area was smaller than that of its purple parent’14 S838’.The segregation ratio of purple heading individuals to non-purple individuals fitted to the ratio of 3:1 in F2 population,which indicates that purple heading of Chinese cabbage was a quality trait and consistent with genetic pattern of a single dominant gene.Purple height ratio(purple height/leaf head height),purple width ratio(purple width/leaf head width)and purple area ratio(purple area/leaf head area)were used to describe purple size trait in purple single plant of the F2 generation,and results indicate that the broad-sense heritability of these three parameters was 94.00%,87.72%and 83.33%,respectively.The result meant that the variation of purple size was mainly controlled by genetic factors,while the external environment showed little influence.The frequency distribution histograms showed that the purple height ratio and the purple width ratio were accorded with normal distribution but the purple area ratio showed positively skew distribution,which indicated that the purple size trait was a quantitative character.Further analysis found the high correlation existed between purple height ratio,purple width ratio and purple area ratio.According to the measurement operation,the purple area ratio was accurate but more complicated to measure.However,measurement of the purple height ratio was simple.Moreover,the purple height ratio was accompanied with high hereditary capacity and highly correlated with the purple area ratio.Hence,the purple height ratio can be used instead of the purple area ratio to define the purple size of the purple heading Chinese cabbage.