优质蛋白玉米籽粒性状的遗传效应

Genetic Effects of Quality Protein Maize on Kernel Traits

选用8个胚乳性状差异显著的优质蛋白玉米(QPM)自交系,采用GriffingI交配设计组配,通过对亲本、F1和F2的鉴定,探讨主要籽粒性状的遗传效应和杂种优势,为有效利用热带硬质QPM种质改良、扩增我国温带QPM种质以及QPM籽粒性状改良和硬质QPM品种选育提供依据。结果表明,籽粒百粒重、百粒体积、胚乳修饰度和籽粒密度在F1和F2代都表现一定的正向杂种优势;胚乳修饰度在F1代存在正反交差异,母体效应明显;4个性状的F2代表型值与中亲值的相关性最大;百粒重和百粒体积主要受母体效应控制,基因效应以显性效应为主;胚乳修饰度主要受种子直接效应控制,基因效应以加性效应为主;籽粒密度主要受母体效应控制,基因效应以加性效应和显性效应同等重要。这4个籽粒性状的细胞质效应均较小,主要受核基因控制。

To efficiently use tropical hard quality protein maize （QPM） germplasm in enriching temperate QPM germplasm, improving kernel traits, and developing hard QPM hybrids, the genetic effects and heterosis of 8 QPM inbreds with different endosperm traits and their F1 and F2 progenies were evaluated via Griffing I diallel mating design. The hundred-kernel weight （HKW）, hundred-kernel volume （HKV）, endosperm modification （EM）, and kernel density （KD） showed positive heterosis in F1 and F2 generations. EM showed differences in F1 reciprocal crosses, indicating obvious maternal effect. Correlation analysis showed that values of HKW, HKV, EM, and KD in F2 generation had the biggest correlation coefficients with the average parental values. Maternal effect was the main factor on HKW, HKV, and KD, while direct genetic effect was mainly on EM. Gene actions for HKW, HKV, EM, and KD were dominant, dominant, additive, and additive ＆ dominant, respectively. Cytoplasmic effect was little for the above 4 kernel traits suggesting that kernel traits are mainly controlled by nuclear genes.