青贮玉米耐旱关键指标的筛选及其遗传研究

Screening and genetic research for drought tolerance key index in silage maize

以6份不同耐旱性的青贮玉米自交系为材料,采用GR IFFING方法2的双列杂交,经通径分析,明确了青贮玉米籽粒产量耐旱系数的关键指标为根冠比、叶面积、叶绿素含量、光合速率4个指标,建立了籽粒产量耐旱系数回归方程;估算了关键指标的一般配合力、特殊配合力和相应的遗传参数。结果表明,5个指标的一般配合力方差明显高于特殊配合力方差,基因累加效应占主导地位。广义遗传力h2B(%)最高为光合速率达93.07。狭义遗传力h2N(%)最高为籽粒产量耐旱系数达18.62。籽粒产量耐旱系数指标宜在早代选择效果好,而根冠比、叶面积、叶绿素含量、光合速率指标4个指标宜加强杂种优势的利用。

By diallel crossing of Griffing method 2,path analysis were carried out with 6 silage maize inbred lines which were different in drought tolerance characters.The main results were summarized as follows.The key index of grain yield drought index in silage maize was ratio of root/top,ear leaf area,chlorophyll contents and photosynthetic rate.The regression equation of grain yield drought index in silage maize was conducted.It was evaluated for four key index as well as normal combining ability,special combing ability and corresponding genetic parameters.The results showed the normal combining ability of the four characters was obviously higher than special combining ability and additive effect of the genes were dominant.The best h2B（%） for photosynthetic rate was 93.07,the best h2N（%） for grain yield drought index was 18.62,respectively.When selecting grain yield drought index we considered in earlier generation.We should make the best of maize heterosis for ratio of root/ top,ear leaf area,chlorophyll contents and photosynthetic rate.