黄瓜苗期耐低温性及相关形态学性状的遗传分析

Genetic Analysis of Chilling Tolerance and Correlation Morphological Characters of Cucumber Seedling

以4个耐低温性不同的自交系9504,9507,9506和9517为材料,按Griffing方法Ⅱ配制完全双列杂交组合,对亲本与F1进行低温处理,每天光照处理7.5h,强度为30μmol.m-2·s-1,白天12℃,夜间8℃,共处理14d,调查黄瓜耐寒指数、叶面积、株高、节数、茎粗、干物质重等性状,经方差分析和逐步回归分析,结果表明,黄瓜耐寒指数与株高、节数、茎粗、干物质重等形态学性状关系密切,上述5个性状的遗传符合加性—显性模型。耐寒指数广义遗传力高,适合于早代选择。显性度0.953,由6对基因控制。株高和节数的广义遗传力、狭义遗传力均较高,环境影响较小,适合于早代选择。茎粗这个性状可在早代选择,注意优良基因的聚合。对于干物质重来说受环境影响较大,可晚代选择。配合力分析表明,亲本9507的一般配合力最高,组合9506×9507的特殊配合力最高,遗传相关分析表明耐寒指数与这4个性状均呈显著正相关关系。通径分析表明干物质重对黄瓜耐寒指数最重要的性状,其他性状影响较小。

According to the Griffing method II,4 materials（9504,9507,9506 and 9517）which were in different tolerance of low temperature to configure completely diall hybrid combination were selected.The parents and F1 were carried on low-temperature treatment of given 12/8℃ in day/night,with 7.5 hours everyday by the light intensity of 30μmol·m^-2·s^-1 for 14 days.Several characters were investigated such as the chilling tolerance index,leaf area,plant height,pitch number,stalk diameter and plant dry weight.Through the variance and gradually regression analysis,the results showed that the relationship of chilling tolerance index,plant height,pitch number,stalk diameter,plant dry weight were osculation and accorded to additive-dominant model.The broad heredity ability of the chilling tolerance index and stem diameter was strong and suited for early generation-choice.The chilling tolerance index,controlled by 6 allele genes,had a dominant degree with 0.953.The higher broad/narrow heredity ability and smaller environmental effect in the plant height and pitch number also suited for early generation-choice.Regarding bigger environmental effect of the plant dry weight,it was suitable for late generation-choice.Genetic correlation analysis indicated that the chilling tolerance index reached remarkable level with other 4 characters（plant height,pitch number,stalk diameter,plant dry weight）.Combining ability analysis indicated that the generally combining ability of parent 9507 was the highest,the specially combining ability of combination 9506×9507 was the highest.Path analysis indicated that plant dry weight was the most important character of the chilling tolerance index of cucumber,and other characters＇ effects were smaller.