十三份玉米新自交系的育种潜势分析

Breeding potential analyses of 13 new inbred lines in maize

为明确玉米新自交系的育种潜力,以13份新自交系、8份骨干系和5份标准自交系为材料,通过农艺性状鉴定和SSR分子标记分析,研究自交系间的遗传差异;按Griffing方法Ⅳ组配210个杂交组合,分析产量配合力和杂种优势表现。结果显示,新自交系K351和K311自身性状优良;以遗传相似系数0.696为阈值,用类平均法(UPGMA)将26份自交系划分为8个类群,即常见5大类群和3个新类群,其中K115等10个新自交系被划分到3个新类群。K61等6个新自交系产量一般配合力(GCA)达极显著(P<0.01)正效应,高于多数骨干自交系;在四川双流和云南宣威试点,比对照显著(P<0.05)增产的组合分别有18个和3个,其中K61×K143和21-ES×K61在2个试点均显著(P<0.05)增产,分别平均增产33.16%和22.81%。综上,新自交系K61、K143和K115产量GCA最高,自身农艺性状较好,其中K61和K115种质新颖,是理想的高产育种亲本;K311、K962和K365产量GCA较高,自身性状良好,具有高产育种潜力,但植株偏高,有待进一步改良。

In order to clarify the breeding potential of new inbred lines,genetic diversities of 13 new inbred lines,eight elite inbred lines and five standard inbred lines were studied by agronomic character identification and SSR markers.210 combinations were obtained according to Griffing method IV,and the combining ability and heterosis of yield were analyzed.The results showed that K351 and K311 were new inbred lines with good agronomic traits per se.By using genetic similarity coefficient of 0.696 as the threshold,26 inbred lines were divided into eight groups including five common groups and three new groups by unweighted pair-group method with arithmetic means(UPGMA),in which ten new inbred lines such as K115 were divided into three new groups.Six new inbred lines including K61 had significantly(P<0.05)positive general combining ability(GCA)effect of yield,higher than that of the most of elite inbred lines.There were 18 and three combinations with yield increase over CK significantly(P<0.05)in experiment site of Shuangliu,Sichuan and Xuanwei,Yunnan,respectively,in which K61×K143 and 21-ES×K61 had significant(P<0.05)yield increase at both sites,with an average increase of 33.16%and 22.81%,respectively.In summary,the new inbred lines K61,K143 and K115 had the highest GCA of yield and good agronomic traits,in which K61 and K115 were novel germplasms,they were ideal parents for high-yield breeding.K311,K962 and K365 had the higher GCA of yield and good agronomic traits,which had the potential for high-yielding breeding,however,the plant height needed to be further improved as they were kind of the higher plants.