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题名	毒药树生殖生物学及种群生态学的初步研究
作者	陈国科
学位类别	硕士
答辩日期	2005
授予单位	中国科学院昆明植物研究所
授予地点	中国科学院昆明植物研究所
导师	彭华
关键词	毒药树 植物生殖生态学 花部特征 结实特性 传粉生物学 种群生态学 人为干扰 保护
其他题名	A preliminary study of reproductive biology and population ecology of Sladenia celastrifolia Kurz
学位专业	植物学
中文摘要	本文围绕毒药树的生殖生物学和种群生态学进行了初步研究，主要是从生殖构件（花、果实和种子）和人为干扰对种群的数量特征影响这两方面进行探讨。植物的生殖构件的研究是个体水平上的生殖生态学研究，植物的开花、结实都是与此紧密相关的，围绕毒药树的生殖构件，我们对其传粉生物学、结实特性以及与此相关的生殖对策进行了探讨。另外，在全球变化的大背景下，人类活动对地球环境的破坏日益加剧，野生生物所依赖的生境在逐渐地散失，本文以毒药树种群为研究单位，从种群数量特征的角度探讨了人类活动所造成的生境破坏对毒药树的影响。1．毒药树的传粉生物学毒药树的花序为二歧聚伞花序，花序的大小有很大的差别，每个花序平均含10朵花。花为两性花，花开时花瓣基部有明显的分泌物。毒药树的P／。比约为720．0，依据相关标准，繁育系统为兼性异交。在子房基部存在膨大的蜜腺，其细胞相对周围组织的细胞要小，属于非结构蜜腺。综上所述，毒药树的花部特征表现出虫媒性质。野外的观察表明中华蜂（APis cerana）为了取食花瓣基部的分泌物而达到为毒药树传粉的目的。阴天及雨天对访花者的访花频率有显著影响。在一天中中华蜂的活动也有明显的规律，随着气温的升高，中华蜂的访问频率随之升高。毒药树的花尊形态在整个花期和果期表现出明显的变化，幼果期时毒药树宿存的花尊紧包幼果，果实成熟时其花警又完全展开，这种变化是一种适应机制，它有利于对幼果的保护和对成熟果实和种子的传播。2．毒药树的结实特性同一种群内不同植株的果实重量之间并没有明显的差异，果实重量在同一种群内分布是均匀的。毒药树的果序内不同轮次果实之间的重量存在明显的差异，从第一轮到第三轮果的重量依次递减。毒药树的结籽率极低，平均每1000个果中含13颗成熟种子。毒药树成熟种子和败育种子在外形上存在很大的差异。败育的种子中未发现胚的结构，成熟的种子饱满，外形如米粒，胚乳丰富，胚的结构十分明显，这一发现纠正了100多年来分类学家对该物种种子的错误描述。3．毒药树种群动态及人为干扰的影响在全球变化的大背景下，人类活动对生命系统的各个等级都有明显的影响，日益严重的人为干扰不可避免地影响毒药树种群的数量特征。我们采用了基于树轮年代学（Dendrochronology）的交叉定年（cross Dating）技术，确定了毒药树年龄与胸径之间的关系，分析了受人为干扰程度不同的两个种群的年龄结构、静态生命表和存活曲线，并对这两个种群进行了比较分析。从年龄结构来看，严重受干扰种群的幼苗库相对不足，I龄级个体数比例为12．7％，II III、IV龄级个体数所占比例为80．3％，种群衰退趋势明显；未受干扰的种群幼苗库相对充足，年龄结构呈现稳定种群的特征。从生命表来看，这两个种群的生命表也存在差异，其中最明显的就是严重受干扰的种群的工龄级和11龄级的死亡率为负，这是其幼苗库不足的一个直接反映，该种群的持续发展受到很大的限制。严重受干扰种群的期望寿命随着龄级的增长总体上呈现降低的趋势，而受干扰很少的种群的I龄级个体期望寿命最高，说明其幼龄个体的生存能力处于最佳状态，种群的持续发展具有稳定的后续资源。 两个种群的存活曲线都表现出低龄级个体死亡率高的特征，但未受干扰的种群各龄级个体的死亡率的变化幅度较小。毒药树种群的各项特征与鹅掌揪（Liriodendron chinense（Hemsl.）Sarg.）及其他几种濒危植物的相关特征相似，对毒药树的保护已十分必要，除了在野外建立相应的毒药树保护点之外，在植物园中培植人工种群也是必须的。
英文摘要	This article deals with the reproductive ecology of Sladenia celastrifolia, mainly from aspects of the reproductive module and the impacts of human disturbance on the populations of this species. Both pollination biology and fruiting characteristics are related to the reproductive module. On the basis of the research of these two aspects, this article made a preliminary discussion of the reproductive strategy of this species. On the ground of global changing, mankind is making more and more serious damage to the earth. The wild habitat, which is necessary to the survival of the wild livings, is under great threat. In this paper, we analyses the age structure and quantitative characteristics of two populations. On the basis of these researches, we discussed the conservation of the populations of this species. 1. Pollination Biology There are about 10 flowers in the dichasium of Sladenia celastrifolia. The floral diameter is 11 ?,and there is obvious nectar on the basic part of the petals. The pollen-ovule (P/O) is 720. Based on Cruden's criterion, the breeding system would be termed xenogamy. There is obvious floral nectary on the basis of the ovary. The cells of the floral nectary are smaller than those of the petals and ovary. We haven't found vascular bundle in the floral nectary, and no stomas have been found on the surface of it. The honeybees were found to be responsible for the pollination of Sladenia celastrifolia. And the honeybees prove to be more active when the temperature becomes higher in a single day. The floral syndrome indicates that there would be little chance for the flowers to be pollinated by wind. The flowers do not lose their sepals during the fruiting period, and the sepals play a great role in protecting the developing fruits and dispersing of the ripe fruits. 2. Fruiting Characteristics The weight of all the trees in a population is unique. However, there is obvious discrepancy among the fruits on different position of the infructescence. The seed set of Sladenia celastrifolia is very low, and there are about 13 ripe seeds in 1000 fruits. There are many differences in anatomic structure between the ripe seeds and the abortive seeds. The embryo and the endosperm are obvious in the ripe seeds, while those of the abortive seeds cannot be found. This discovery has corrected the wrong description of the seed of this species, which has lasted for more than 100 years. 3. Population Dynamics and Human Disturbance Sladenia celastrifolia Kurz has a scattered distribution in Southwest China, especially in Yunnan province. However, the quantitative characteristics of many populations have been largely affected by increasing human activities. Using the relationship between age and diameter at breast height, the authors analyzed the age structure, life table and survival curves of two populations of this species, which have been affected by human disturbance to different degrees. In the heavily disturbed population, there are much fewer young-aged individuals. The individuals of the age class I only take up 12.7%, whereas those of the age class II, III, and IV together account for 80,3% of the total individuals of the population, indicating an obvious declining of the population. In contrast, the age structure of the unaffected population proves to be stable, with sufficient young-aged individuals. The life tables of the two populations are different: the death rates of the age class I and class II are minus, an indication of the shortage of young-aged individuals. The expectation of life of younger individuals is higher than those of the older individuals in the heavily affected population, while the situation is quite the contra in the unaffected population. The survive curves of both populations are characterized by high death rate of young-aged individuals, while the death rates of all age class of the unaffected population are stable. The age structure and dynamics of the populations of this species are similar to those of some other endangered species in China, such as Liriodendron chinense (Hemsl.)Sarg and Cathaya argyrophylla Chun et Kuang. Although Sladenia celastrifolia Kurz has not been regarded as an endangered species until now, it has the typical attributes of an endangered species according to the standards of IUCN. Therefore, much attention should be paid for the conservation of this species, it is necessary to establish nature reserves in its original habitat and ex-situ conservation zone in botanic garden.
语种	中文
公开日期	2011-10-25
页码	62
内容类型	学位论文
源URL	[http://ir.kib.ac.cn/handle/151853/804]
专题	昆明植物研究所_昆明植物所硕博研究生毕业学位论文
推荐引用方式 GB/T 7714	陈国科. 毒药树生殖生物学及种群生态学的初步研究[D]. 中国科学院昆明植物研究所. 中国科学院昆明植物研究所. 2005.

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