夏菊耐热性指标筛选和综合评价

在夏季高温条件下,不同品种夏花型菊花Dendranthema×grandiflorum开花能力有较大差异。为了比较品种间的耐热性差异和确定筛选有关耐热性的评价指标,对5个品种夏菊的生理特性、解剖结构和花期性状等方面的13个指标进行测定,并采用主成分分析、隶属函数分析以及回归分析法对它们进行耐热性综合评价。结果表明：群体花期、叶片超氧化物歧化酶（SOD）活性、叶片丙二醛（MDA）含量和净光合作用日积累量可作为耐热性评价的指标;根据建立的回归方程计算的综合评价值比较,5个品种夏菊的耐热性依次为‘火炬’〉‘紫荷’〉‘粉荷’〉‘金光’〉‘金星’;5个品种的耐热性预测值与综合评价值呈极显著相关。

Heat tolerance for summer blooming of Chrysanthemum

Summer chrysanthemum varieties in seasonal high temperatures differ in their blossoming characteristics. To evaluate heat-tolerance and to choose heat resistance indicators for Chrysanthemum that bloom in summer, physiological indicators, anatomic structure, and blooming traits were among 13 indicators, studied in five cultivars--‘Huoju＇ , ‘Zihe＇, ‘Fenhe＇, ‘Jinguang＇ , and ‘Jinxing＇ . Principal component and subordinate function analyses were used. Results showed that both superoxide dismutase （SOD） activity and malondialdehyde （MDA） content in leaves as well as the integral of the diurnal net photosynthetic rate （Pn） could he used as heat-tolerance evaluation indexes. A comprehensive evaluation model D = - 1.818 ＋ 0.013x2 ＋ 0.008x6 ＋0.002xs - 0.000 048x13, where x2 is the blooming period, x6 is the SOD activity in leaves, xs is the MDA content in leaves, and x13 is the integral of diurnal Pn, was developed. A significant correlation （P 〈 0.001, R = 0.973） between predictive value （Vp） and D was also found. The decreasing order for heat tolerance of D with the five cultivars was ‘Huoju＇ 〉‘Zihe＇ 〉 ‘Fenhe＇ 〉 ‘Jinguang＇ 〉 ‘Jinxing＇ ECh, 4 tab. 14 ref.]