关键词: 小麦, 穗部性状, 主基因+多基因, 遗传效应

Abstract:

【Objective】 Panicle traits are important yield traits of wheat, occupying an important position and role in wheat yield composition. Carrying out genetic research on wheat panicle traits and analyzing its genetic mechanism provide theoretical and practical guidance for formulating high-yield breeding strategies and improving breeding efficiency. 【Method】 Based on the length of the main stem, the number of spikelets, the number of grains per spike, and the number of spikelets, the main gene + polygene mixed genetic model of quantitative traits was used to obtain the parental product 34 and the male parent under different ecological conditions. BARRAN and its derived F_7:8, F_8:9 generation recombinant inbred line population (RIL) were used for genetic model analysis and genetic parameter estimation of panicle traits to determine the number of genes controlling various traits, and to estimate genetic effect values and heritability. 【Result】The best genetic model for panicle length and spikelet number were B-2-1 (PG-AI), which was consistent with two pairs of linked major genes + additive-epistasis polygene genetic model. The polygenic heritability of spike length was 90.64%, the polygenic heritability of spikelet number was 89.52%, the average of environmental variation of spike length accounted for 9.39% in phenotypic variation, and the average of environmental variation of spikelet number accounted for 10.50% in phenotypic variation; Major gene heritability was 69.39%, Polygenes heritability rate was 29.94%, and the average environmental variation accounted for 2.18% in phenotypic variation. Additive effect value of the first pair of main genes controlling the number of spikes and the additive effect value of the third pair of major genes are equal, and the same was 4.56, which has a positive effect. The additive effect value of the second pair of major genes was the same as the additive effect of the first pair of major genes × the second pair of major genes × the third pair of major genes, both of which were -1.44, and are negative effects. The additive and additive × additive epistasis interaction values were equal to the additive and the second pair of major gene additions × the third pair of major gene additive epistatic interactions, both of which were -6.02. Additive and the first pair of major gene additive × the third pair of main gene additive epistatic interaction effect value is 0.18, the multi-gene additive effect value is 0.15, showing a lower positive genetic effect; H-1(4MG-AI) was best-fitting genetic model for the spikelet number traits, which showed that their inheritance was controlled by incorporating four major genes additive-epistasis genetic model. The heritability of the main gene was 81.50%. The additive effect values of the main genes in the first to fourth pairs were 0.22, 0.18, -0.20, and 0.24, respectively, the additive and epistatic interactions of the first pair of major genes × the first pair of major genes were -0.170, the additive effect value of the additive and the first pair of major genes × the third pair of major genes was 0.240. the additive effect value of the additive and the first pair of major genes × the fourth pair of major genes was -0.200, additive and the second pair of major genes × the third pair of major genes × additive effect value and additive and the second pair of major gene additive × fourth pair of major gene additive epistatic interaction value absolute value, the effect in contrast, the former value was 0.030, and the latter value was -0.030. The additive effect value of the additive and the third pair of major genes × the fourth pair of major genes was 0.060. 【Conclusion】The panicle traits of wheat are mainly polygenic genetic effects, which are in line with quantitative genetic characteristics and are susceptible to environmental influences. The number of spikelet grains has the genetic characteristics of the main gene. The main gene has high heritability and is affected by the environment. The number of spikelets can be used as a direct indicator to effectively improve the early selection of panicle traits, achieving single plant directional selection and improving breeding efficiency.

Key words: wheat, panicle traits, major gene + polygene, genetic effect