不同欧洲型黄瓜苗期耐热性综合评价

为研究欧洲型黄瓜幼苗对高温的适应性,准确鉴定和筛选耐热种质,加快欧洲型黄瓜耐热性育种进程。以20份欧洲型黄瓜的高代自交系为材料,在人工高温(42℃)胁迫处理下,研究欧洲型黄瓜芽期和幼苗在高温胁迫过程中的形态、生理及生化指标的变化,应用隶属函数、主成分分析等方法进行系统的综合评价。结果表明:高温胁迫下,不同欧洲型黄瓜幼苗形态指标和生理指标对高温胁迫反应差异显著;通过主成分分析结果,将9个单项指标转成4个相互独立的综合指标,并结合聚类分析法将供试20份种质划分为3类;通过逐步回归建立欧洲型黄瓜苗期的耐热性评价数学模型D=0.517 49-0.001 13 RL-0.000 53 MDA+0.000 19 POD,估算精度大于92.11%,可用于对不同欧洲型黄瓜幼苗的耐热性评价和预测,从而避免单一指标的片面性和不稳定性。

Comprehensive Evaluation on Heat Tolerance of Different Europe-type Cucumber Germplasm at Seeding Stage

To study the adaptability difference under high temperature of different Europe-type cucumber at seeding stage, which could supply the qualification and screening of tolerance germplasm, and accelerate the progress of heat-tolerance of breeding. The heat tolerance of 20 Europe-type cucumber germplasm was investigated. The change of morphologic indicators, physiological and biochemical indexes were researched on heat stress. Principal component analysis, subordinate function analysis, clustering analysis were used to evaluate the heat tolerance of germplasm. The results showed that, there were significantly different responses of morphological and physiological indices among genotypes under heat stress. Principal component analysis reduced the 9 single indices to 4 independent comprehensive components, and the cluster analysis was used to divide 20 genotypes into three kinds of heat tolerance types. The mathematical model for Europe type cucumber heat tolerance in seeding stage was established, D=0.517 49-0.001 13 RL-0.000 53 MDA+0.000 19 POD, and the evaluation accuracy of the equation was higher than 92.11%. It is a reliable way to evaluate and forecast the heat tolerance of europe-type cucumber, and could avoid the bias and the instability of single index analysis.