西瓜亲本遗传差异与杂种优势的相关性

Correlation between genetic diversity and heterosis of watermelon parents

为了探讨西瓜亲本主要性状的遗传距离与其产量、中心糖度杂种优势的相关性,本试验选用9个西瓜亲本及其配置的18个不完全双列杂交组合为材料,采用形态调查法测量其子叶叶形指数、子叶面积、开花期、叶面积、雌花节位、坐果率、果实发育期、坐果距离、单株产量、中心糖度10个性状,并分析了西瓜亲本10个性状的遗传距离与其单株产量、中心糖度杂种优势的相关性。结果表明:西瓜亲本间10个性状的遗传差异显著,亲本的3个主成分的欧氏距离为0.577～3.874。在亲本遗传距离与产量杂种优势的三次曲线回归方程Y=-6.82x3+44.59x2-81.27x-41.03在0.25水平上显著;和亲本的遗传距离与中心糖度杂种优势的反函数回归方程Y=7.69-6.97/x在0.05水平上显著。表明西瓜亲本10个性状的遗传距离与其单株产量、中心糖度杂种优势间存在显著的相关性。

To research the correlations between genetic diversity and heterrosis of plant yield and center sugar of wa- termelon parents, nine watermelon parents and 18 hybrids derived from 6 female parents and 3 male parents, were selected as materials. Ten morphological traits, including cotyledon ratio, cotyledon area,leaf area, node to the 1 st female flower, days to the 1 st female flower, fruits per plant, days to fruit growth, fruit length, plant yield, center sugar content, were sur- veyed by form investigation method, and the correlation between genetic distances of principal component on the 10 morpho- logical traits of 9 watermelon parents and heterosis of plant yield and center sugar were analysed. The reasuhs showed that the genetic differences of the 10 morphological traits were significant. The Euclidean distances of three principal component values on the 10 morphological traits were in the range of 0. 577-3. 874. The regression relations were significant in the cu- bic equation between heterosis of plant yield and genetic distances Y=-6. 82X3 ＋44. 59x2-81. 27x-41.03 （P= 0. 25 ）and in the inverse equation between heterosis of center sugar content and genetic distances Y= 7.69-6.97/x （ P= O. 05 ）. In conlusion, genetic diversity of watermelon parent on the 10 morphological traits shows significant correlation with heterosis of plant yield and center sugar content.