玉米种质苗期耐冷性状的遗传分析

摘要：早春低温冷害是黑龙江省主要的自然灾害之一，已成为影响本区域玉米产量水平提高的重要因素。本研究选择不同耐冷玉米种质8份，按Griffing Ⅱ的设计组配，分析低温逆境下玉米出苗及幼苗期性状的遗传规律。相关分析表明，相对出苗指数、相对出苗率、相对苗干重、相对根干重两两相关，相对出苗率与相对根总长相关，上述性状适合作为玉米幼苗耐冷性鉴定的指标。不同亲本的GCA方差、不同组合的SCA方差在相对出苗率、相对发芽指数、相对苗干重、相对根干重、相对根总长等性状上的差异显著。非加性基因效应在相对出苗率、相对发芽指数、相对苗干重、相对根干重、相对根总长中起到重要作用，且狭义遗传力普遍较低，各性状均低于50%，高低次序为相对发芽指数>相对出苗率>相对根干重>相对苗干重>相对根总长，上述性状选择适宜在中晚代进行选择。

Genetic analysis of cold tolerance trait in maize germplasm seedling stage

Abstract: The low temperature in early spring maize area is one of important natural disaster of Heilongjiang province and has become the important factor that elevated the corn yield level in this district. 8 inbred lines that come from different cold tolerate and origins in this research and made by Griffing Ⅱ design, gain the genetic regularity in emergence period and seedling period with low temperature adverse circumstances. Correlation analysis indicates that correlations exist between relative germination index, relative seedling ratio, relative plant dry weight, relative root dry weight each other. Relative seedling ratio has correlation with relative root total length. These traits can be used as seedling indexes for cool-tolerance identification. There are significant differences in the traits among GCA variance in different parents, SCA variance in relative seedling rate, relative seedling index, relative height of seedling, relative dry weight of seedling, relative dry weight of root, relative number of side root and relative length of the entire root. Additive gene effect is important in relative emergence ratio ,relative germination index , relative plant dry weight, relative root dry weight, relative total root length ,and narrow-sense heritability are generally lower than 50% ,the sequence from high to low are relative germination index, relative seedling ratio , relative root dry weight ,relative plant dry weight , relative root total length. These traits should be selected in higher generations.