不同播深环境下玉米耐深播性状杂种优势及遗传效应解析

为确定玉米耐深播性状的杂种优势表现及遗传规律,本研究以耐深播性不同的22份亲本及组配的22份F1杂交种为试材,在3、15和20 cm播深下,采用加性-显性-母体遗传模型(ADM)分析了13个耐深播性状的杂种优势、遗传效应及配合力大小.结果表明,随播深增加玉米亲本和F1的出苗率、苗长、根长、中胚轴粗及根重降低,而中胚轴长...

Heterosis and Genetic Effects Analysis of Deep-Seeding Traits in Maize Under Different Sowing Environments

To determine the heterosis and genetic effects of maize deep-seeding tolerance-related traits. 22 F₁ hybrids and 22 parents with different deep-seeding tolerance were used as materials to analyze the heterosis, genetic effect, and combining ability of 13 deep-seeding tolerance-related traits by ADM (additive-dominance-maternal effect genetic model) under 3, 15, and 20 cm depths in this study. It was found that: with the increase of sowing depths, seeding emergence rate (RAT), seedling length (SDL), root length (RL), mesocotyl coarse (MESC), and root weight (RW) of parents and F₁ were decreased, however, mesocotyl length (MESL), coleoptile length (COLL), mesocotyl and coleoptile total length (MESL+COLL), mesocotyl length: coleoptile length ratio (MESL/COLL), coleoptile coarse (COLC), seedling weight (SDW), mesocotyl weight (MESW), and coleoptile weight (COLW) were increased; The Pearson correlation and PCA (principal component analysis) showed that the synergies or antagonisms of among 13 traits formed the response mechanism of maize deep-seeding tolerance. The 13 traits displayed obviously, F₁ heterosis index were 90.97%~175.64%; Except for MESL/COLL and COLW, other traits showed positive mid-parent and over-parent heterosis. Thus, to improve maize breeding efficiency, it is necessary to pay attention to the selection of main basic materials, namely high-parent, middle-parent, and female-parent, as well as the influence of heterosis should be considered. The additive genetic effect of MESL, COLL, MES+COLL, MESL/COLL, and RL were predominated, these traits could be modified in early generations by simple backcross or single cross recombination; Other traits displayed additive and dominance main effects, and interaction effects with environment, these traits could be modified at specific sowing depths to reflect their heterosis. The general and special combining abilities of parents and F₁ in 13 traits had significant differences, 8802A male-parent with good comprehensive additive effect value was screened, H21×8802A progeny may have the potent to improve and develop some elite deep-seeding tolerant maize materials. The study would be helpful for maize deep-seeding tolerance breeding.