加拿大一枝黄花有性生殖特征研究

加拿大一枝黄花Solidago canadensis L.是分布于我国的危害性最为严重的入侵种之一,它既可以通过有性生殖又可以通过无性生殖进行繁殖.对加拿大一枝黄花有性生殖的相关特征,如花序和小花的生物学特性、结实率和传粉方式等进行了研究.结果表明,加拿大一枝黄花的性系统为雌全性系统,每花序总花数为(15.16±1.67)个,缘花/盘花值为3.07±0.64.对成熟果实透明后进行的结实率统计表明,其结实率较低.套纱布网袋后的结实率极显著低于开放性授粉的,表明其花序是需要昆虫传粉的类型.加拿大一枝黄花的花序结构特征和开放式样显示出有利于增加异交的特点.尽管其结实率相对较低,但整个植株结实量大,仍需要防止其通过有性生殖产生的种子进行远距离的扩散和在新分布地区建立种群. 花有性生殖的相关特征,如花序和小花的生物学特性、结实率和传粉方式等进行了研究.结果表明,加拿大一枝黄花的性系统为雌全性系统,每花序总花数为(15.16±1.67)个,缘花/盘花值为3.07±0.64.对成熟果实透明后进行的结实率统计表明,其结实率较低.套纱布网袋后的结实率极显著低于开放性授粉的,表明其花序是需要昆虫传粉的类型.加拿大一枝黄花的花序结 特征和开放式样显示出有利于增加异交的特点.尽管其结实率相对较低,但整个植株结实量大,仍需要防止其通过有性生殖产生的种子进行远距离的扩散和在新分布地区建立种群. 花有性生殖的相关特征,如花序和小花的生物学

Traits of sexual reproduction in Solidago canadensis L.

Solidago canadensis L., belonging to the Asteraceae family, is a noxious weed in China. It can reproduce both asexually and sexually. In this paper, traits associated with sexual reproduction, such as characteristics of capitulum and florets, percentage of seed set and mode of pollination were studied. The results showed that the sexual system of Solidago canadensis is gynomonoecy in which each individual capitulum has both female and hermaphrodite florets. The numbers of florets per capitulum were 15.16±1.67(mean±SD), and the ratio of the numbers of peripheral florets to disk florets is 3.07±0.64. The percentage of seed set, as assessed from cleared achenes, was relatively low in Solidago canadensis. The percentage of seed set of gauze-bagged capitula was significantly lower than that of open-pollinated capitula. This demonstrates that seed production of Solidago canadensis depends on ento-mophilous pollination. Architectural traits and floral display of capitula of Solidago canadensis are likely to increase the chance of cross-pollination. Although the percentage of seed set was relatively low, the overall seed production per clone was huge. To stop further spread of Solidago canadensis, management efforts are needed to prevent long-distance dispersal, and population establishment in new areas from seeds produced by sexual reproduction.