【作者】 赵睿；

【导师】 陈小勇；

【作者基本信息】 华东师范大学 ， 生态学， 2010， 硕士

【摘要】 植物的繁殖物候不仅可以反映植物长叶、开花、结果这一完整的繁殖生长发育过程及周期,也响应着气候环境变化给植物带来的选择效应,且对与植物共生的动物也会产生重要的影响。榕及其榕小蜂为目前所知专一性最强的共生体系之一。“一对一”的原则体现为每一种榕专门由其专一的榕小蜂授粉,榕小蜂的后代又由这种特有的隐头花序(榕果)所供养。不同地点榕属植物的繁殖物候因气候环境等影响而存在差异；与榕属共生的榕小蜂也会在其生活史周期中,突出表现为进入接受期和出飞期时可能出现时间和地域差异。榕-榕小蜂的共生体系为研究是否由于植物繁殖物候的选择压力,导致榕属植物不同个体间生长情况差异及其榕小蜂的生活史周期特征与宿主的高度配合提供了良好的研究对象。薜荔及其薜荔小蜂主要广泛分布于我国的东南沿海地区。1980s起我国相关研究者陆续在浙江、台湾和福建对两者的特性和共生关系进行了研究,但对薜荔的繁殖物候一年内存在几次花期仍有一定的争议,有关薜荔小蜂的完整生活史周期也存在不同的结论。为探究薜荔繁殖物候、共生的薜荔榕小蜂生活史的特征,及薜荔与薜荔小蜂共生关系的配合,我们选取浙江地区2个大陆种群——宁波市天童地区的28株、台州临海市地区的23株和2个岛屿种群——舟山市桃花岛的22株、东极岛的15株薜荔,进行为期1年半连续的物候观察,以期解决浙江地区薜荔不同种群繁殖物候特征及其差异；阐明薜荔小蜂生活史与薜荔花期的配合；从物候角度上为支持薜荔小蜂物种分化及区域尺度薜荔物种基因流受限的原因提供参考。论文主要结论为：1)我国浙江地区不同薜荔与薜荔小蜂在生活史上始终是紧密配合的。薜荔雄株在一年中有三次花期,春、夏、秋季各一次,而多数雌株仅一次花期。薜荔春季以萌生雌果为主、夏秋两季萌生雄果,且产生的花粉数量第二次花期>第一次花期>第三次花期。其结果是春季让多数薜荔小蜂为薜荔传粉、结实,少量小蜂哺育后代为第二次花期做准备；夏秋两季小蜂进入雄果哺育更多的小蜂后代。且此规律年复一年,周而复始。2)薜荔小蜂繁殖能力较强,性比偏雌。薜荔小蜂生产二或三代小蜂,其中小蜂数量第二次花期>第一次花期>第三次花期。其中,薜荔小蜂能产生较多的雌性后代,4个薜荔小蜂种群性比均明显偏雌,有利于保障小蜂后代的数量和小蜂种群的延续。薜荔小蜂的进入接受期和出飞期时可能受到薜荔气候环境的长期影响调节,也有可能是小蜂的生活史周期特性驱动了薜荔当前物候特征的形成。3)薜荔雌雄花序直径、长度和质量均随时间推移而逐渐增大。薜荔雄花序进入D期时,4个种群间花序直径和长度均有极显著的差异。表明榕果发育时,易受到气候、环境等因素的影响,而小蜂发育成熟出飞与薜荔榕果大小无关。雌性榕果发育至B期时,临海和东极种群内、种群间大小均呈极显著的差异。当小蜂出飞寻找新生榕果进入时,靠榕果散发出的气味而非榕果的大小。薜荔榕果进入B期后其大小和质量均迅速增长,且呈幂函数增长趋势,且雌果的增长趋势略大于雄果,这与雌性榕果生长繁殖代价有关。此时小蜂产卵促使虫瘿花发育迅速膨胀或小蜂传粉导致子房发育膨大,随后榕果大小缓慢增长,质量继续增加。雌花序发育较雄花序迅速,雌花序发育周期较长,约为第一代雄花序发育周期的两倍；雌花序成熟时的千粒重与其直径、鲜重显著相关,花托厚度可能是除榕果直径影响外,导致各种群间种子总粒数有较大差异的主要原因之一4)薜荔不同种群受纬度梯度、生境偏好、地形地貌、岛屿与大陆的地理隔离、气候条件影响,进入各生长周期的时间先后不同,大致表现为临海种群>天童种群>桃花种群>东极种群。5)薜荔三个姊妹种小蜂的不同分布格局的形成原因之一是受薜荔物候差异的影响。体现为临海薜荔种群——Sp.A、Sp. B小蜂、天童薜荔种群——Sp.A小蜂、东极薜荔种群——Sp.C小蜂、桃花薜荔种群——Sp.A、Sp. C小蜂相配合,形成了不同的“小蜂巢”特点。且Sp.B小蜂的出飞期早于Sp.A小蜂、Sp.C小蜂,而Sp.A小蜂的出飞期又比Sp.C小蜂早10天左右。更多还原

【Abstract】 Phenology is the study of periodic plants and animals life cycle events and how these are influenced by seasonal and interannual variations climatic factors. Reproductive phenology of plants describes the temporal pattern of flowering, fruiting and seed maturing. Plant reproductive phenology has a close relationship with its pollinating animals.Figs and their pollinating wasps are among the most tightly linked interspecific interactions. Each fig species is pollinated by the unique specialized fig wasps, and fig wasps developed in syconium of fig species. The fig-fig wasp system is a model system for testing co-evolution of reproductive phenology. Reproductive phenology of figs and the life cycle of pollinating wasps may provide important information for the understanding of the reproductive basis of the mutualists which are facing global warming.Ficus pumila and the pollinating wasps are widely distributed in southeastern China. Since 1980s, researchers had revealed some characteristics in symbiotic relationship between F. pumila and its pollinating wasps in Zhejiang, Taiwan and Fujian of China. However, there are some different opinions and conclusions about the flowering phenology of F. pumila and the life cycle of pollinating wasps.In this study, we selected two mainland populations-Tiantong of Ningbo(28 individuals), Linhai of Taizhou (23 individuals), and two island populations-Taohua island of Zhoushan (22 individuals), Dongji island of Zhoushan (15 individuals) to investigate the reproductive phenology of F. pumila, and the life cycle of pollinating wasps, tried to understand their symbiotic relationship.The main conclusions were as follows:1) Reproductive phenology of F. pumila and the life cycle of pollinating wasps are always closely related. Male figs flower three times per year, while most female figs once. In spring, female F. pumila individuals produce abundant syconia, while male F. pumila individuals have a small crop. However, in summer and autumn, male F. pumila individuals have a mass crop. In general, crops of male F. pumila individuals are in the order of second crop> first crop> third crop. In spring, most wasps entered female syconia to pollination, while in summer and autumn, wasps entered male syconia to oviposit. This rule remains the same year after year.2) Reproductive capacity of pollinating wasps of F. pumila was strongly, which can breed three generations per year mostly. The offspring amount are in the order of second generation> first generation> third generation. Most of wasps’offspring were female, and the sex ratio about 0.34-0.42. Moreover, the reproduction of pollinating wasps and the reproductive phenology of F. pumila can influence each other.3) The diameter, length and weight of syconia were all increased with the time. There were significantly difference in diameter and length of male syconia at phase D among four populations, and at phase B there were significantly difference in diameter between LH and DJ F. pumila populations. Totally, at the first generation of syconia, female grew rapidly than male one, and female syconia were about twice of male syconia. When the pollinating wasps became emergence, they will find the receptive syconia by the flavor in spite of the size of syconia.At phase E, in female syconia,1000-seed weight was significantly correlated with diameter and fresh weight. Thickness of receptacle may be the important factor to affect the number of seeds, besides the diameter.4) Three cryptic pollinators were co-existence in Zhejiang province. Sp. A and Sp. B were distributed in LH, Sp. A was distributed in TT, Sp. C was distributed in DJ, and Sp. A and Sp. C were distributed in TH. In spring, Sp. B emerged first, followed by Sp. A and Sp. C. In Taohua island, Sp. A emerged about 10 days earlier than Sp. C.更多还原