锦绣含笑耐寒性研究

Study of the cold-tolerance of new varieties Michlia maudiae 'Jinxiu'

低温是含笑属植物引种栽培的主要限制因子之一,探明含笑属新品种‘锦绣含笑’的耐寒性,了解其与台湾含笑、深山含笑和乐昌含笑在耐寒适应性上的差异,对该新品种的推广应用有重要意义。该文对4种含笑的叶片在自然低温条件下受冻后的形态特征进行观测,利用相对电导率配合logistic回归方程计算低温半致死温度(LT50),并运用聚类分析和隶属函数法对叶片解剖结构进行耐寒指标的筛选和综合评价。结果表明:4种含笑受冻后的叶片形态特征有较大差异,低温半致死温度的变化范围为-11.599—-15.263℃;通过聚类分析将叶片9个结构指标分成3组,分别筛选出栅栏组织厚度、叶片厚度和细胞结构紧密度等3个指标进行隶属函数综合评价,锦绣含笑的耐寒性介于台湾含笑和深山含笑之间,4种含笑的耐寒性由强到弱依次为台湾含笑>锦绣含笑>深山含笑>乐昌含笑。

Low temperature is one of the major limiting factors for the introduction and cultivation of Michelia plant. In this paper,to evaluate the cold tolerance of M. maudiae ‘Jinxiu＇,the morphological characteristics of M. maudiae ‘Jinxiu＇,M. compressa（ Maxim.） Sarg.,M. maudiae Dunn. and M. chapensis Dandy leaves were observed under natural low temperature. And their low semi-lethal temperatures（ LT50） were obtained on the basis of leaf relative conductivities combined with Logistic Equation. The cold-tolerance indexes of leaf anatomical structure were also screened and comprehensively assessed by hierarchical cluster analysis and Membership Function Method. The results showed that the morphological characteristics of the leaves were different between 4 Michelia varieties. The range of LT50 of all tested Michelia plants was-11. 599—-15. 263 ℃.Nine morphological characteristics were clustered into 3 categories. Indices such as palisade tissue thickness,blade thickness and blade tightness were found to be suitable for using a comprehensive evaluation by membership function. The cold tolerance of M. maudiae ‘Jinxiu＇was between M. compressa（ Maxim.） Sarg. and M. maudiae Dunn. The cold-tolerance of 4 Michelia varieties were in such a decreasing order as M. compressa（ Maxim.） Sarg. M.maudiae ‘Jinxiu＇M. maudiae Dunn M. chapensis Dandy.