玉米分子标记遗传距离与产量杂种优势关系的研究

Study on relationship between genetic distance based on molecular markers and heterosis on yield of maize

以8个白粒优良优质蛋白玉米自交系及其按完全双列杂交配制的28个组合为材料,研究SSR分子标记遗传距离与28个杂交组合的产量及产量配合力的相关性。结果表明:SSR分子标记遗传距离与杂交组合F1产量及产量特殊配合力之间呈极显著正相关,相关程度为中度相关,但决定系数都很小;亲本自交系的平均遗传距离与产量的一般配合力之间不存在显著的相关关系。将28个组合根据SSR标记的聚类结果,划分为杂种优势群内组合和杂种优势群间组合,当仅研究杂种优势群内组合的分子标记遗传距离与产量及产量特殊配合力之间的相关性时,相关程度达到高度相关,决定系数也很高,因此分子标记遗传距离与玉米杂种产量优势的相关程度与被研究材料间的遗传差异密切相关。分子标记遗传距离与F1产量之间的相关性小于与产量特殊配合力之间的相关性,分子标记遗传距离与F1产量之间的相关程度不足以准确预测出玉米杂种的产量,但在一定程度上能反应杂种产量的高低。

In the research, 8 white elite quality protein maize (QPM) inbreds and 28 crosses from the 8 QPM inbreds di-allel mating were attained to study the relationship between genetic distance (GD) based on SSR markers and hybrids performance including Fl yield and combining ability for yield. The results showed that GD was highly significantly positively correlated with F1 yield and special combining ability (SCA) for yield, the correlated degree was medium and determination coefficient was low; the average GD for each inbreds was not correlated with general combining ability (GCA) for yield. When the 28 crosses were classified into inter-group crosses and intra-group ones based on SSR markers and only study the relationship between GD and Fl yield and SCA of the intra-group crosses, both correlation were highly significantly positive and the correlated degree, determination coefficient were high. So the correlation between GD based on SSR markers and heterosis for yield was tightly related to the involved materials. It was unpractical to exactly predict the Fl yield by using SSR markers, but to some extent it can explain the degree of hetrosis.