煙草(nicotiana tabacum L.)의 韓國 在來種과 orient種에 대한 量的形質의 遺傳分析 Ⅰ. 雜種强勢와 組合能力

Genetic analysis of quantitative characters in diallel crosses among Korean local and oriental(nicotiana tabacum L.) Ⅰ. Heterosis and combining ability

This experiment was conducted to evaluate the potential genetic variability present in intra-and inter-type hybrids, and to obtain estimates of heterosis and combining ability in crosses among Korean local and Oriental tobacco varieties. On the average, significant heterosis was observed in yield, leaf length and width,stem height ranged from 6.2% to 10.4%, and -6.9% for days to flowering in F₁ hybrids. Whereas in F₂ population, there was no significant heterosis for all characters studied except days to flowering which showed -3.6%. Estimates of variance for general combining ability (GCA) were significant for all characters studied in F₁, hybrids and F₂ populations. Specific combining ability (SCA) variances were significant for all characters studied in F₁ hybrids and for all characters in F₂ populations except yield and nicotine content. The variances of GCA were predominant, and no significant maternal effect due to the reciprocal cross was found in all characters investigated in F₁ hybrids and F₂ populations. There were significant correlations between generations in variances and ranks of parental GCA effects estimated from GCA analysis of F₁ and F₂ generations for all characters studied. The inter-type combinations exhibited positively larger SCA effects of combination, estimated from SCA analysis, than the intra-type combinations.