College of Agronomy, Hunan Agricultural University, Changsha, Hunan, China.
Maize Engineering Technology Research Center of Hunan Province, Changsha, Hunan, China.
PLoS One. 2024 Oct 3;19(10):e0303602. doi: 10.1371/journal.pone.0303602. eCollection 2024.
Maize is one of the main food crops in the world, and cultivating high-yield and high-quality maize varieties is of great significance in addressing food security issues. Leaves are crucial photosynthetic organs in maize, and leaf senescence can result in the degradation of chlorophyll. This, in turn, impacts photosynthetic activity and the accumulation of photosynthetic products. Delaying leaf senescence and increasing carbon assimilation can enhance grain yield and biomass production. The stay green of maize is an important trait closely related to yield, feed quality and resistance. Therefore, this study employed multi-generation joint analysis of major genes and a polygene model to investigate the genetic inheritance of stay green-related traits. Four populations (P1, P2, F1 and F2) were obtained by crossing T01 (stay green) × Xin3 (non-stay green) and T01 (stay green) × Mo17 (non-stay green) under two environments. Six stay green-related traits, including visual stay green (VSG), number of green leaves (GLNM), SPAD value of ear leaf at anthesis (SPADS), SPAD value of ear leaf at maturity (SPADM), absolute green leaf area (GLAD), grain yield per plant (GYP), displayed continuous variations with kurtosis and skewness values of absolute value less than 1 and distribution close to normal. They were characterized by typical inheritance of quantitative traits, with these traits demonstrating the transgressive segregation. The correlation analysis among the traits revealed that five stay green traits have a positive impact on yield. VSG, GLNM and SPADM in the two populations were regulated by the two major genes of additive effects plus additive-dominance polygene model with a major gene heritability varying from 89.03 to 95.95% in the F2 generation. GLAD in TMF2 was controlled by two major genes of equal-additive dominance effects with high heritability (93.47%). However, in TXF2, GLAD was regulated by two major genes of additive-dominance interaction effects plus additive-dominance polygene model. These results provide important genetic information for breeding, which could guide the improvement of stay green-related traits. They also lay a foundation for quantitative trait loci mapping of the stay stay-green traits in maize.
玉米是世界上主要的粮食作物之一，培育高产、优质的玉米品种对于解决粮食安全问题具有重要意义。叶片是玉米的主要光合作用器官，叶片衰老会导致叶绿素降解。这反过来又会影响光合作用活性和光合产物的积累。延缓叶片衰老和增加碳同化可以提高籽粒产量和生物量产量。玉米的持绿性是一个与产量、饲料质量和抗性密切相关的重要性状。因此，本研究采用主基因和多基因模型的多世代联合分析，研究了与持绿性相关性状的遗传。在两个环境下，通过 T01（持绿）× Xin3（非持绿）和 T01（持绿）× Mo17（非持绿）的杂交获得了四个群体（P1、P2、F1 和 F2）。六个持绿相关性状，包括视觉持绿（VSG）、绿叶数（GLNM）、开花期穗叶 SPAD 值（SPADS）、成熟期穗叶 SPAD 值（SPADM）、绝对绿叶面积（GLAD）和单株籽粒产量（GYP），表现出连续的变异，峰度和偏度值的绝对值小于 1，分布接近正态。它们具有典型的数量性状遗传特征，这些性状表现出超亲分离。性状间的相关分析表明，五个持绿性状对产量有正向影响。两个群体中的 VSG、GLNM 和 SPADM 受加性效应加加性显性多基因模型的两个主基因调控，F2 代主基因遗传率在 89.03%到 95.95%之间。TMF2 中的 GLAD 由两个具有高遗传率（93.47%）的等加性显性效应的主基因控制。然而，在 TXF2 中，GLAD 由加性显性互作效应加加性显性多基因模型的两个主基因调控。这些结果为玉米持绿相关性状的育种提供了重要的遗传信息，可为持绿相关性状的改良提供指导。它们也为玉米持绿性状的数量性状位点图谱奠定了基础。
