Abstract:

Genetic analysis of eight traits associated with stem soluble carbohydrate content under rainfed and well-watered conditions were undertaken using 150 doubled haploid population lines (DHLs) derived from two Chinese common wheat cultivars, Hanxuan 10 and Lumai 14. Mean values of all traits of DHLs were intermediate between two parents with the variation coefficients ranging from 6.96% to 65.72% under two irrigation regimes. All traits of DHLs showed substantial transgressive segregation. And, phenotypic means of all traits of DHLs and their parents under rainfed condition were higher than those under the well-watered. Poor correlations were observed among stem soluble carbohydrate contents at three stages. But significant or very significant positive correlations were observed between stem soluble carbohydrate content at 14 d after flowering (SSC_f14) and other traits. The heritability and the number of genes for all traits showed great differences between two irrigation regimes. Under rainfed condition, the heritability of SSC_f14 was the highest, up to 0.49, that of grain-filling efficiency (GFE) was the lowest (0.11), and that of other traits intermediated between them. Under well-watered condition, on the contrary, the heritability of GFE was the highest (0.65), while that of SSC_f14 was the lowest (0.51). Under rainfed condition, the number of genes controlling GFE, AESSC (accumulation efficiency of stem soluble carbohydrate), SSC_f14, and SSCm (stem soluble carbohydrate content at the maturity stage) was the most with 27, 26, 22, and 20, respectively; but that of RESSC (remobilization efficiency of stem soluble carbohydrates) was only nine. Under well-watered condition, the number of genes was 19 for SSC_f14, and 4 for RESSC. The complementary interactions were observed for SSCm under two irrigation regimes and SSC_f14 under well-watered condition, and the overlapping interactions were detected for RESSC and GFE under two irrigation regimes and AESSC under well-watered condition, while no gene interaction was found for other traits. It indicated that the inheritance of these traits is complex, and there are different expression patterns of these genes according to different developmental stages or water regimes in wheat.

Key words: Wheat, Doubled haploid population, Soluble carbohydrate, Genetic analysis