采用石蜡切片法对夏蜡梅[Sinocalycanthus chinensis (Cheng et S. Y. Chang) Cheng et S. Y. Chang]和美国蜡梅(Calycanthus floridus L.)及属间杂种‘红运’ (S. chinensis×C. floridus ‘Hong Yun’)叶、茎和根的横切面解剖结构进行了比较观察。 观察结果显示:夏蜡梅、美国蜡梅及杂种‘红运’的叶、茎和根的横切面解剖结构有较高的共性,但仍有明显区别。 杂种‘红运’的叶片厚度、主脉维管束横截面面积和海绵组织厚度与夏蜡梅比较接近,而与美国蜡梅差异较大;杂种‘红运’叶的栅栏组织厚度与海绵组织厚度的比值( P / S)和栅栏组织厚度与叶片厚度的比值(P / L)均介于 2 个亲本之间,P / S 和 P / L 2 个指标均为美国蜡梅最高、夏蜡梅最低。 杂种‘红运’茎的直径、皮层细胞层数、皮层厚度、皮层厚度与茎半径的比值、木质部厚度和维管束面积等指标的数值均大于美国蜡梅和夏蜡梅。美国蜡梅根的髓部不发达,夏蜡梅根则有明显的髓部,而杂种‘红运’根的髓部较发达;美国蜡梅根的木质部和木栓层均最厚,髓部分布的大型导管数量最多;杂种‘红运’根的皮层最发达,木质部最不发达,髓部的大型导管最少。根据营养器官的解剖结构特征与生态特性的关系推测:夏蜡梅具有不喜强光、稍耐阴的生态特性,美国蜡梅的耐热性和光合能力最强,而杂种‘红运’比其母本夏蜡梅有更好的生态适应性。

The transection anatomical structures of leaf, stem and root of Sinocalycanthus chinensis (Cheng et S. Y. Chang) Cheng et S. Y. Chang, Calycanthus floridus L. and intergeneric hybrid S. chinensis×C. floridus ‘ Hong Yun’ were compared and observed by paraffin method. The observation results show that although transection anatomical structures of leaf, stem and root of the three plants are high common, but there still are distinct differences. The leaf thickness, transection area of vascular bundle in main vein and spongy tissue thickness of hybrid ‘ Hong Yun’ are close to S. chinensis, but greatly differ from C. floridus. Thickness ratios of palisade tissue to spongy tissue ( P / S) and palisade tissue to leaf (P / L) of hybrid ‘Hong Yun’ both lie between its two parents, and values of P / S and P / L of C. floridus are the highest and those of S. chinensis the lowest. The values of stem diameter, layer number of cortex cell, cortex thickness, ratio of cortex thickness to stem radius, xylem thickness and vascular bundle area of hybrid ‘Hong Yun’ all are higher than those of S. chinensis and C. floridus. The pith in C. floridus root is underdeveloped but that in S. chinensis root is distinct, while that in hybrid ‘Hong Yun’ root is more developed. The xylem and phellem in C. floridus root both are the thickest and number of big vessel in pith is the most. While in hybrid ‘ Hong Yun’ root, the cortex is the most developed, but xylem is the most underdeveloped and number of big vessel in pith is the least. According to relationship between anatomical structure characteristics of vegetative organs and ecological characteristics, it is conjectured that S. chinensis possesses the ecological characteristics of inadaptability to strong light and slightly shade tolerance, C. floridus has the best heat resistance and photosynthetic capacity, while the ecological adaptation of hybrid ‘Hong Yun’ is better than female parent S. chinensis.