关键词: 早熟, 矮秆, 高粱, 遗传分析

Abstract:

【Objective】In order to identify the genetic effect of early-maturing and dwarf traits on sorghum male-sterile line P03A, here we, provide a theoretical basis for sorghum early-maturing and dwarf breeding improvement by genetic analysis on growth period and plant height. 【Method】In 2016, sorghum male-sterile line P03A,L025A, L080A, L081 and P02A were used as female parent lines, and restoring line L242, L2381, LNK1, L280, L237, and L298 were used as male parent lines the F₁ hybrid seeds were obtained by NCⅡ crossing method. And in the winter of 2016, F₂ seeds were harvested from F₁ selfing plantlets in Hainan province. During 2017-2018, Combining ability analysis on growth period and plant height traits were performed, together with 4 generation conjoint analysis from hybrid F₁ and F₂ population using mixed major gene plus poly-gene inheritance model. P03A and L237 were selected as female and male parent respectively. 【Result】 Hybrid combination P03A/L237 show the characters of short growth period and short plant height through interaction of the 2 parent lines. P03A contribute to shortening the growth period and plant height in hybrid. Compared with the rest 4 sterile lines, the hybrid combinations with P03A show shorter growth period and plant height, and heritability on the 2 traits was identified. 4-generation analysis of P03A/L237 on growth period and plant height were performed using major gene plus poly-gene inheritance model, which indicate that growth period and plant height traits were both controlled by two major genes with additive-dominate-epistatic effects and poly-genes. Analysis result of growth period suggest that additive effect is higher than epistatic and dominate effects. Heritability of major genes is 81.13%, and heritability of poly-genes is 10.36% respectively. 91.49% phenotypic variation is conducted by major genes plus poly-genes, and 8.51% phenotypic variation is conducted by environmental factors. Analysis of plant height indicate that additive effects and dominant effects of the first major gene are all stronger than the second major gene, and the dominant effect is much more important. Heritability of major genes and poly-genes is 84.80%, and 6.89% respectively. 8.31% phenotypic variation is conducted by environmental factors. 【Conclusion】Genetic effects of growth period and plant height of sorghum sterile line P03A were analyzed in this study. It was identified that the heritability of the two traits mentioned above are relatively high, not easily affected by environmental factors, and with stable hereditary characters. Thus, P03A can be utilized due to its early maturing and dwarf genes in sorghum hybrid breeding, which can meet the requirement of sorghum mechanized production.

Key words: early maturity, dwarf, sorghum, genetic analysis