1回의 循環選拔을 거친 배추 集團에 殘存하는 遺傳變異

Residual Genetic Variances on Two Chinese Cabbage Population after One Cycle of Recurrent Selection

Estimates of various components of genetic variance and heritability were obtained using North Carolina Design I for total plant weight, head weight and days to maturity on two Chinese cabbage populations, 189C₁ and 129C₁, that had each undergone one cycle of recurrent selection. Correlations between mean of selfed progenies (S₁) and half-sibs were also investigated. Average degrees of dominance for head weight and days to maturity were in the range of no or partial dominance in population 129C₁ while they were within complete or over-dominance range in 189C₁. Average degree of dominance for total weight showed the opposite trend to the two above-mentioned characters in both populations. Although the genetic systems are implied to be in. the additive range, estimates of heritability were lower in 129C₁ compared to 189C₁ for both total weight and head weight. These were attributed to the greater environmental susceptibility of the former population. Correlations between mean performance of S₁ and half-sibs were highly significant for all three characters in population 129C₁ but not for any one character in population 189C₁. The implications of the above results in future improvement programs involving these populations were also discussed.