不同环境下中国主要玉米自交系叶片叶绿素衰减速率特性研究

Attenuation Rate of Chlorophyll in Maize Inbred Lines in China under Different Environments

因为玉米灌浆后期叶片叶绿素含量变化可直接影响植株的光合效率并最终影响产量,同时叶片光合效率以及叶绿素代谢受光照环境影响较大,所以对不同环境下玉米叶片叶绿素衰减速率进行初步研究,可为培育出适宜种植环境的优良高产玉米品种提供理论依据。以66份玉米自交系为试材,分别种植于海南三亚和辽宁沈阳两地,持续测量植株穗位叶叶绿素含量,并计算叶绿素衰减速率及不同环境叶绿素衰减速率的差值,分析不同环境对叶绿素衰减速率特性的影响。结果表明:玉米叶片叶绿素衰减速率的广义遗传力为55.82%,环境与基因型互作的平方和达到基因型的48.59%;衰减速率越接近于7.846spad·d^(-1)的自交系受环境变化的影响越小;以海南数据为标准,叶绿素衰减速率小于7.486spad·d^(-1)的自交系中有70.37%在海南环境下表型低于辽宁环境,而在叶绿素衰减速率高于7.486spad·d^(-1)的自交系中则有71.79%在海南环境下表型高于辽宁环境。不同种群间叶绿素衰减速率无显著性差异。玉米叶片叶绿素衰减速率是由多个微效基因参与调控的数量性状,并存在部分调控基因可响应环境变化且对表型有较大的影响;可响应环境变化的调控基因分为两类,在相同环境具有截然相反的影响效果,且在外界影响下两类基因对表型的效力相等;玉米中参与叶绿素衰减速率的调控基因可能广泛分布于玉米的整个基因组中,以孟德尔方式独立遗传,其中大部分相关基因间不存在相互作用,通过累加效力来影响玉米的表型。

The change of chlorophyll content in the leaves of maize at the late stage of grain filling can directly affect the photosynthetic efficiency of the plant and eventually influence the yield of maize. Because the photosynthetic efficiency of maize leaves and chlorophyll metabolism are greatly affected by the light, the purpose of this experiment was to study the effects of different environments on the attenuation rate of chlorophyll in maize leaves, providing a theoretical basis for breeding high-yielding maize varieties suitable for planting environments. Sixty-six maize inbred lines collected from China were used as the experimental materials. They were planted in Sanya, Hainan and Shenyang, Liaoning, respectively. Chlorophyll content of the ear leaves of the plants were continuously measured from the beginning of maize pollination until the chlorophyll content of the leaves did not change completely. The attenuation rate of chlorophyll and the difference under different environments were calculated, and the effects of different environments on the attenuation rate of chlorophyll were analyzed. The generalized heritability of the attenuation rate of chlorophyll in maize leaves was 55.82%, and the square sum of the interaction between the environments and genotypes was 48.59% of the genotype. The inbred lines with an attenuation rate of chlorophyll about 7.846 spad·d^-1（similar to the mean chlorophyll attenuation rate） were lessaffected by environmental changes. Among the inbred lines which the attenuation rate of chlorophyll was less than 7.486 spad·d^-1, 70.37% of them had lower phenotype value in Hainan than in Liaoning. And among the inbred lines with an attenuation rate of chlorophyll more than 7.486 spad·d^-1, 71.79% of them had higher value in Hainan than in Liaoning. There was no significant difference in the attenuation rate of chlorophyll among different populations. The attenuation rate of chlorophyll in maize leaves is a quantitative trait and is regulated by multiple minor genes. There are multiple regulatory genes that respond to the changes in the environment and have a greater impact on the phenotype. Furthermore, we further determined that the regulatory genes that can respond to environmental changes are composed of two kinds of genes that have opposite effects under the same environment. Under the influence of the environment, the two genes have the same effect on phenotype. It is presumed that whether or not it responds to changes in the environment, the genes involved in the regulation of the attenuation rate of chlorophyll in maize may be widely distributed in the entire genome of maize. There is no interaction among most of the related genes and they are inherited independently in Mendelian law. These genes affect the phenotype of maize by additive effect.