首页 | 本学科首页   官方微博 | 高级检索  
   检索      

不同海拔藜芦种群繁殖特征的初步研究
引用本文:廖万金,张全国,张大勇.不同海拔藜芦种群繁殖特征的初步研究[J].植物生态学报,2003,27(2):240-248.
作者姓名:廖万金  张全国  张大勇
作者单位:北京师范大学生态学研究所,生物多样性与生态工程教育部重点实验室,北京,100875
基金项目:国家自然科学基金项目 ( 30 12 50 0 8,30 0 70 135),教育部重点项目
摘    要: 在北京东灵山地区,沿一定海拔梯度,对藜芦(Veratrum nigrum)这一雄花两性花同株的多年生草本植物的繁殖特征进行了初步研究。结果表明:藜芦开花植株的生物量显著大于未开花植株的生物量。藜芦开花植株大小存在最小临界值,总种群的最小临界值为2.61 g,不同种群的繁殖临界值存在一定的差异。根据花粉/胚珠比(Pollen / ovule ratio,P/O比)推测,藜芦应属于以异交为主的混合交配系统。雄花的大小与生物量都比两性花小,而且其开放时间也晚于两性花,但二者的花粉生产量却没有显著差异。这种现象与人们针对雄花两性花同株植物的雄花功能所提出的最优资源分配假说(Optimal resource allocation hypothesis)是一致的。

关 键 词:雄花两性花同株  繁殖特征  资源分配  藜芦
修稿时间:2002年4月27日

A PRELIMINARY STUDY ON THE REPRODUCTIVE FEATURES OF VERATRUM NIGRUM ALONG AN ALTITUDINAL GRADIENT
LIAO Wan-Jin,ZHANG Quan-Guo and ZHANG Da-Yong.A PRELIMINARY STUDY ON THE REPRODUCTIVE FEATURES OF VERATRUM NIGRUM ALONG AN ALTITUDINAL GRADIENT[J].Acta Phytoecologica Sinica,2003,27(2):240-248.
Authors:LIAO Wan-Jin  ZHANG Quan-Guo and ZHANG Da-Yong
Abstract:A preliminary study was conducted on the reproductive features of different populations of Veratrum nigrum along an altitudinal gradient in Dongling Mountains, Beijing. V. nigrum is a perennial, andromonoecious herb. We use P/O ratio (Pollen/ovule ratio) as an estimate of the level of outcrossing. Resource allocation was measured by means of dry weights.We found that the flowering individuals within a population were larger than the non-flowering individuals. The resource allocated to reproduction was strongly correlated with that allocated to vegetative growth. Individuals of V. nigrum would not produce flowers and fruits until a threshold size was reached, which ranged from 1.11 g to 3.98 g in different populations. The minimum size showed no trend along the altitudinal gradient, indicating that an invariable minimum vegetative biomass for the species might exist. Pooled together, a minimum size of 2.61 g for reproduction followed from the regression line. Above the threshold there existed a relatively simple linear relationship between vegetative and reproductive biomass. Population density decreased firstly and then increased along altitudinal gradient, but it seemed that density is not related, in a straightforward way, to the reproductive features of V. nigrum in the study region.Many workers had shown that the flowers of self-incompatible and other xenogamous taxa produced more pollen grains than closely related self-compatible and/or autogamous taxa, while the number of ovules per ovary was rather conservative, in contrast to other floral characteristics. In this article, we estimated P/O ratios both at the level of a hermaphrodite flower and at the level of an individual (including male flowers). We found that the difference in mean hermaphrodite flower P/O ratios among populations was not significant. Hermaphrodite flowers had P/O ratios from 799 to 1 090. However, the difference in mean individual P/O ratios among populations was strongly significant. The lowest individual P/O ratio was 1 601 and the highest was 4 146. According to the correlation between P/O ratios and mating systems established by Cruden, V. nigrum in Dongling Mountains was facultatively xenogamous. There was a positive correlation between the P/O ratios of hermaphrodite flower and the ratios of reproductive to vegetative biomass.Hermaphrodite flowers are mainly distributed at the tip raceme of the panicle, while males are at the lateral racemes. Sometimes, flowers near the base of the lateral racemes are hermaphrodite. Hermaphrodite flowers bloom earlier than male flowers, and the two flower types differed in dry weights. Hermaphrodite flowers averaged 5.10×10-3 g while male flowers averaged 4.04×10-3g. Hermaphrodite flo wers were on average 26% more massive than male flowers. Flower diameter was (1. 42±0.01) cm for hermaphrodite flowers and (1.24±0.01) cm for males. Hermaphrodite flowers were on average 15% larger than male flowers. However, the pollen producti on of hermaphrodite and male flowers remained almost the same. The results docum ented here suggest male flowers of V. nigrum provide resource savings to the plant compared to hermaphrodite flowers. Since male flowers have lower resource use for equal pollen production in comparison to hermaphrodite flowers, they are more efficient at male function than hermaphrodite flowers. These results lend support to the optimal resource allocation hypothesis for the function of male flowers within an andromonoecious sexual system.
Keywords:Andromonoecy  Reproductive features  Resource allocat ion  Veratrum nigrum  
本文献已被 CNKI 维普 万方数据 等数据库收录!
点击此处可从《植物生态学报》浏览原始摘要信息
点击此处可从《植物生态学报》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号