基于农艺性状与光合特性的甘薯耐荫性评价

The Evaluation of Shade Tolerance Based onAgronomic Traits and PhotosyntheticCharacteristics in Sweetpotato

为探索更加合理的甘薯耐荫性评价方式,通过人工遮荫,研究弱光下29个不同甘薯品种(系)的农艺性状、光合指标、产量变化等,并采用不同的评价分类方式对其进行耐荫性评价.结果表明:不同品种(系)在同一单项指标下的耐荫系数不同,同一品种(系)的不同单项指标耐荫系数也存在差异,其中以气孔导度、净光合速率、非光化学猝灭系数和蒸腾速率等光合指标的变异系数较大,分别为69.07%,67.55%,61.91%和49.99%;茎干质量、蔓长、叶面积指数及分枝数的变异系数中等,分别为28.70%,24.90%,24.84%及24.13%.以茎干质量、净光合速率或非光化学猝灭系数等单项指标评价分类结果与产量减幅规律不符,而采用主成分分析、隶属函数分析和聚类分析等方法进行耐荫性综合评价结果更加可靠.

In order to explore a reasonable evaluation method of shade tolerance of sweetpotato,29 different sweetpotato cultivars(lines)were monitored under the circumstance of artificial shade to research the changes on their agronomic traits,photosynthetic characteristics and yield,and evaluate their shade tolerance coefficient through different methods.The results indicated that the shade tolerance coefficient of different cultivars(lines)was different with the same index,and the coefficients of different indexes were different with the same variety(line).The variation coefficients of stomatal conductance,net photosynthetic rate(Pn),non-photochemical quenching coefficient(NPQ)and transpiration rate were relatively larger at 69.07%,67.55%,61.91%and 49.99%,respectively.The variation coefficients of stem dry weight,vine length,leaf area index and number of branches were medium at 28.70%,24.90%,24.84%and 24.13%,respectively.The evaluation results of classification using single index such as Pn or NPQ were inconsistent with the reduction ranges of sweetpotato yield,while comprehensive evaluation was more reliable with these methods,such as principal component,subordinate function and clustering analysis.