PDF(Pubmed)
Abstract：
In vivo maternal haploid induction in isolation fields is proposed to bypass the workload and resource constraints existing in haploid induction nurseries. A better understanding of combining ability and gene action conditioning traits related to hybrid inducers is necessary to set the breeding strategy including to what extent parent-based hybrid prediction is feasible. This study aimed to evaluate the following in tropical savanna in the rainy and dry seasons for haploid induction rate (HIR), R1-nj seed set, and agronomic traits: 1) combining ability, line per se, and hybrid performance of three genetic pools; 2) genetic parameters, the modes of gene action, and heterosis; and 3) the relationships of inbred-general combining ability (GCA) and inbred-hybrid performance. Fifty-six diallel crosses derived from eight maize genotypes were evaluated in the rainy season of 2021 and the dry season of 2021/2022. Reciprocal cross effects including the maternal effect barely contributed to the genotypic variance for each trait observed. HIR, R1-nj seed set, flowering dates, and ear position were highly heritable and additive inherited, while ear length showed dominant inheritance. The equal importance of additive and dominance effects was found for yield-related traits. Temperate inducer BHI306 was the best general combiner for the HIR and R1-nj seed set, followed by two tropical inducers, KHI47 and KHI54. The ranges of heterosis were trait-dependent and slightly influenced by the environment, where hybrids in the rainy season consistently had higher heterosis than those in the dry season for each trait observed. Both hybrid groups derived from tropical × tropical and tropical × temperate inducers showed taller plants, larger ear size, and higher seed sets than the corresponding parents. However, their HIRs were still below the standard check of BHI306. The implications of genetic information, combining ability, and inbred-GCA and inbred-hybrid relationships on breeding strategies are discussed.
摘要：
建议在隔离场中进行体内母体单倍体诱导，以绕过单倍体诱导苗圃中存在的工作量和资源限制。必须更好地了解与杂种诱导物相关的结合能力和基因作用条件性状，以设置育种策略，包括在何种程度上基于亲本的杂种预测是可行的。本研究旨在评估雨季和旱季热带稀树草原的单倍体诱导率（HIR）。R1-nj种子集，和农艺性状：1)配合力，线本身，和三个遗传库的杂种表现；2）遗传参数，基因作用的模式，和杂种优势；3）近交-一般配合力（GCA）与近交-杂种表现的关系。在2021年的雨季和2021/2022年的旱季评估了来自八种玉米基因型的56个二叉杂交。包括母体效应在内的相互交叉效应几乎不影响观察到的每个性状的基因型差异。HIR,R1-nj种子集，开花日期，和耳朵的位置是高度遗传性和加性遗传，而耳长表现为显性遗传。对于产量相关性状，发现加性效应和优势效应同等重要。温带诱导器BHI306是HIR和R1-nj种子集的最佳通用组合器，紧随其后的是两个热带诱导物，KHI47和KHI54。杂种优势的范围是性状依赖性的，受环境的影响很小，对于观察到的每个性状，雨季的杂种始终比旱季的杂种优势高。来自热带×热带和热带×温带诱导物的两个杂种组显示出更高的植物，更大的耳朵尺寸，和比相应的亲本更高的种子集。然而,他们的HIR仍低于BHI306的标准检查。遗传信息的含义，结合能力，讨论了近交-GCA和近交-杂种关系在育种策略上的应用。
