四川苏铁的生态环境及单性繁衍状况调查分析

Investigation on Ecological Environment and Unisexual Propagation of Cycas szechuanmsis

在福建,四川苏铁产区生态环境优越.北部产于沙溪干流的永安、三明、沙县、南平;南部产于永泰、莆田、仙游;东部为连江、罗源.目前永安贡川和桃源洞、三明瑞云山、永泰葛岭、仙游石苍等地尚有野生残存.古树最集中的是沙县淘金山,系宋元遗物,约800-1000 a历史;莆田新县广宫铁树村的有350 a历史,系清初移植的野生植株.福建所有古树及人工栽培的绝大多数都是附近的野生树,因此猜想福建是四川苏铁的原产地.至今未发现四川苏铁的雄株,所有野生栽培的植株清一色为雌株,它没有种子,历史上它一直是单性繁衍,有可能它属于地质年代遗传至今的自然现象.

In Fujian Province, Cycas szechuanmsis grows in an advantageous environment. It is distributed on Yong＇an, Sanming, Shaxlan and Nanping cities in the north, on Yongtai, Putian and Xianyou counties in the south, and on Lianjiang and Luoyuan counties in the east. At present, there are remnants of the wild C. szechuanrnsis in Gongchuan town and Taoyuandong of Yong＇an, Ruiyun Mountain of Sanming, Geling of Yongtai and Shlcang of Xianyou. The ancient C. szechuanrnsis trees, which have been passed down from Song and Yuan dynasties, are mostly centralized in Taojin Mountain of Shaxian County, and they have a history of 800- 1000 years. In Guanggong Iron-tree village of Xinxian, Putian City. there is such an old tree of 350 years from Qing Dynasty. The ancient and planted C. szechuanmsis trees are both distributed in Fujian Provinces therefore, Fujian is supposed to be its habitat. Today, the male tree of C. szechuanrnsis is not discovered, and in other words, all of the wild C. szechuanrnsis trees are female; furthermore, there is no C. szechuanmsis seed found in the nature. It means this ancient species still enjoys a unisexual propagation, which is probably a natural phenomena passed down from Geological Eras.