Comparison of heat tolerance of ray florets of different chrysanthemum cultivars at different flowering stages | 不同菊花品种不同开花阶段舌状花耐热性比较

Chinese. 摘　　要：对‘早黄’、‘长紫’、‘丰韵里’和‘南农玉碟’4个夏菊品种不同开花阶段的花枝进行45℃高温处理,测定其舌状花的抗氧化系统酶活性和非酶物质、可溶性糖、可溶性蛋白、丙二醛、脯氨酸含量等主要生理指标,并结合露地高温下田间栽培的菊花花序开放能力,用主成分分析结合隶属函数值法,对不同菊花品种不同开花阶段的耐热性进行综合评价和比较。结果表明：高温胁迫下菊花舌状花过氧化物酶（POD）活性先升高后降低,超氧化物酶（SOD）活性及抗坏血酸（AsA）、还原型谷胱甘肽（GSH）和可溶性蛋白含量变化趋势存在品种间差异,可溶性糖含量下降而丙二醛（MDA）及脯氨酸含量增加;菊花在露色期耐热能力明显低于初花期和盛花期,其中‘早黄’耐热性最强,‘南农玉碟’最弱,‘丰韵里’和‘长紫’介于两者之间。基于SOD活性及GSH、可溶性蛋白和脯氨酸含量建立的耐热性预测回归方程可用于菊花品种花器官耐热性评价。

English. Physiological and biochemical indexes,such as activities of antioxidant enzyme,and non-enzyme substances,contents of soluble sugar,soluble protein,malondialdehyde and proline were investigated in ray florets of four summer-flowering chrysanthemum cultivars（＇Zaohuang＇,＇Changzi＇,＇Fengyunli＇and＇Nannongyudie＇）at three flowering stages（pigmented stage,initial flowering stage and full flowering stage）under 45 ℃ condition.The heat resistance of different cultivars at different stages was evaluated synthetically by principal component analysis and subordinate function,and compared by inflorescence abilities in natural high temperature condition.The results showed that the POD activity of ray florets increased first and decreased then,the SOD activity,AsA,GSH and soluble protein contents changed differently among cultivars,and the soluble sugar content decreased,while MDA and proline contents increased.The ray florets at pigmented stage were more susceptible to high temperature than initial and full flowering stages.Among the four cultivars,＇Zaohuang＇is the highest heat tolerance one,＇Nannongyudie＇is the lowest one,and＇Fengyunli＇and＇Changzi＇showed moderate tolerance.The heat tolerance predicting regression equation established by activity of SOD,contents of GSH,MDA and proline could be used to evaluate inflorescence heat tolerance of other chrysanthemum cultivars.