快中子诱变突变体的表型鉴定及配合力效应分析

为明确252CF裂变快中子辐照诱变得到的6个玉米突变体的配合力效应，评价其在玉米育种实践中的利用价值，以昌7-2、Mo17、B73、LY0986和LY1621为测验种父本(P1)，6个突变体fu18312、fu1603、fu17138、fu18321、fu18398和fu18362为被测系母本(P2)，在前期表型鉴定的基础上，对11份参试材料的11个农艺性状，按NCII设计(不完全双列杂交设计)分为两组，组配30个杂交组合进行配合力效应分析。结果表明，6个突变体的一般配合力（general combining ability, GCA）效应值在同一性状或不同性状上存在较大差异。其中矮秆、低穗位突变体fu18312株高和穗位高的GCA效应为负效应，降秆作用显著，可用于抗倒性的改良；叶夹角突变体fu1603和黄绿叶突变体fu17138多数性状的GCA效应均为正效应，可用于高秆、大穗、多粒型丰产品种的选育，但应注意与矮秆品种搭配，以防倒伏。尽管fu17138叶缘黄化，但结实正常，与对照相比单株产量降低，因此，可作为标记性状在种子生产上加以利用，以保护知识产权。所配组合中，（LY0986×fu17138）为强优势杂交组合，单株产量的特殊配合力（Special combining ability, SCA）表现为较高的正效应，为品种选育奠定了种质基础，为快中子诱变突变体的进一步改良和利用提供了理论依据。

Phenotypic Identification and Combining Ability Effect Analysis of Mutants by Fast Neutron Irradiation

In order to evaluate the combining ability effects and utilization value of maize breeding, six mutants (fu18312, fu1603, fu17138, fu18321, fu18398 and fu18362) obtained by 252CF fast neutron irradiation were used as female parents, while Chang 7-2, Mo17, B73, LY0986 and LY162 were used as male parents. On the basis of the phenotypic characterization, 11 agronomic traits of 11 materials were divided into two groups according to NCII design (incomplete diallel cross design). And the combining ability effects of 30 cross combinations were analyzed. The results showed that the general combining abilities (GCA) of 6 mutants varied greatly in the same or different traits. The GCA effect of fu18312 (dwarf and low-spike mutant) were negative on plant height and ear height, which should be beneficial to the improvement of lodging resistance of hybrid combination. The GCA effects of fu1603 and fu17138 on traits of yield were mostly positive, which should be used to the breeding of new variety with higher stem, bigger ear and more grain number. Due to yellow leaf margins and lower yield compared with the wild type, fu17138 could be used as a marker in seed production for protecting intellectual property rights. A strong dominant hybrid combination (LY0986×fu17138) was screened through analyzing the combining ability of the main agronomic traits of 6 mutants, which provided germplasm resources for breed selection and a theoretical basis for further improvement and utilization of fast neutron mutants.