【作者】 罗长维；

【导师】 陈晓鸣；

【作者基本信息】 中国林业科学研究院 ， 森林保护学， 2012， 博士

【摘要】 麻疯树是我国西南地区重要能源植物，其种仁富含脂肪酸油，是生物柴油的优质原料。在我国西南、华南热区，特别是我国西南干热河谷地区，麻疯树已经大面积种植。目前麻疯树的传粉生态学研究还局限于对访花昆虫种类组成与昆虫的简单访花行为的观察等研究。为了进一步明确麻疯树传粉昆虫特征及主要传粉昆虫的传粉行为生态学，本研究通过在四个试验点对麻疯树传粉昆虫种类及其传粉能力进行调查，对麻疯树花部特征与花部挥发物对主要传粉者的影响进行研究，通过隔离试验对不同传粉类群对麻疯树的繁殖贡献进行检测，分析麻疯树的传粉适应性。研究结果如下：1.云南省麻疯树传粉昆虫的地理分布特征对四个试验点的麻疯树传粉昆虫组成进行调查，对传粉昆虫的地理分布特征进行分析。研究结果表明在不同试验点的麻疯树传粉者种类分别为34~45种，四个试验点传粉者种类总数多达113种，分属于蜜蜂类、独蜂类、蚁类、双翅目类、鞘翅目类、鳞翅目类与半翅目类共七种传粉功能群。蜜蜂类、双翅目类与鞘翅目类为主要传粉昆虫。不同试验点之间的传粉昆虫组成在传粉功能群水平上完全相似，但在科级、属级与种级水平上则极不相似。传粉昆虫种类在世界范围内的动物陆地地理分布与中国地理分布大都为广泛分布类型。因此，麻疯树的传粉系统包含多种传粉类群，为典型的泛化传粉类型，传粉者种类组成明显受植物生境影响，且传粉者多为分布广泛的泛化传粉者。2.主要传粉昆虫及其传粉行为对访花者种群数量、捕食者、访花酬物、携粉情况、传粉部位、单次传粉效率与访花性别偏向进行观察检测，对传粉者的访花行为对麻疯树繁殖成功的影响进行了分析。研究结果表明，麻疯树的主要传粉功能群为蜜蜂类、蚁类、双翅目与鞘翅目。访花者的捕食者有蜘蛛、螳螂与猎蝽等多种昆虫。访花者的主要酬物为花蜜。主要传粉功能群体表均携带花粉，体表不同部位携粉量不同。尽管蜜蜂类与双翅目昆虫能访问多种植物，由于它们的访花行为与花粉清理行为，其访问麻疯树时转移的花粉均为同质的麻疯树花粉，未携带其它植物花粉，因此不会因携带异质花粉堵塞麻疯树柱头。蜜蜂类与双翅目类的主要传粉部位为喙基部，鞘翅目的传粉部位为腹部。中华蜜蜂与大头金蝇单次落置在同一雌花不同柱头上的花粉数量差异显著，需要多次访问方能使雌花所有柱头充足授粉。中华蜜蜂与小蜜蜂对麻疯树的雌雄花具有偏雄选择倾向，大头金蝇对雌雄花的访问没有偏向，因而蜜蜂类的偏雄访问可能会降低麻疯树雌花的授粉率。因此蜜蜂类与蝇类的一些传粉行为，如携带较大量的花粉，通过头触式传粉、携带同质的麻疯树花粉有助于提高其传粉效率，而另一些传粉行为，如落置在柱头上的花粉数量不均衡性及蜜蜂类的偏雄访花会降低其传粉效率。3.花部特征对传粉昆虫的视觉影响对花粉与柱头微观特征及雌雄花的形态特征进行观察，通过改变花部组成、花冠大小与花部颜色对花部特征对传粉者的视觉影响进行检测，对干旱胁迫下花序开放式样进行观察。研究结果表明，麻疯树柱头干性，花粉粒直径大，含水丰富，具有瘤状突起，利于麻疯树花粉的粘附与快速萌发。雌花花冠直径大于雄花，雄蕊直径显著大于雌蕊直径，雌花与雄花的花冠与花蕊高度一致，利于花粉的移出与落置。去除花冠与花蕊均显著降低花序对蜜蜂与双翅目类的吸引作用，花萼对传粉者没有吸引作用。随着花冠变小，花朵对蜜蜂与双翅目类传粉者的吸引力显著降低。花部颜色的改变显著降低花朵对蜜蜂的吸引作用，但对双翅目类的影响不大。受干旱胁迫的花序开放式样为雌性后熟，雌花开放式样较小，不利于雌花的授粉。因此，麻疯树花部特征通过花部组成、花瓣大小与花蕊颜色影响蜜蜂类与双翅目类昆虫的访花行为。4.花部挥发物对传粉者的嗅觉吸引对麻疯树花序、叶片挥发物经过顶空吸附与离体吸附采集、检测、分析与鉴定，利用触角电位测定仪对中华蜜蜂对麻疯树花部挥发物及其浓度的敏感性进行检测，利用嗅觉生物测定对中华蜜蜂与大头金蝇对挥发物浓度与组成的敏感性进行检测。结果表明，麻疯树花部与叶部最常见的大量成分为罗勒烯与芳樟醇，其次为脂肪烷类。花序与叶片挥发物的释放的昼夜节律明显，二者均在上午释放大量芳樟醇，而下午与晚上均释放少量或不释放芳樟醇；麻疯树花序开放盛期释放的芳樟醇也远高于未开放花序与开败花序。在触角电位生理测定中，中华蜜蜂对麻疯树的花部挥发物均能作出反应，对芳樟醇与所有脂肪醛的反应尤其高。芳樟醇等6种化合物能激起中华蜜蜂反应的起始剂量在0.4～4μg之间，EAG反应强度与化合物的剂量呈正相关。具有EAG活性的6种化合物在最高测试剂量(4000μg)时诱发的反应均未达到饱和。在嗅觉生物测定中，麻疯树开放花序挥发物对中华蜜蜂有显著的吸引作用，但对大头金蝇无吸引作用。因此，麻疯树的花部挥发物对中华蜜蜂有较强的吸引作用，并能产生触角电位生理反应，而对大头金蝇没有吸引力。5.昼夜昆虫的传粉贡献在双柏试验点对麻疯树花朵泌蜜昼夜节律、麻疯树传粉者活动节律的观测，以及套袋分别隔离昼夜传粉类群对昼夜昆虫对麻疯树的传粉贡献进行检测。结果表明，麻疯树的雄花、授粉雌花与未授粉雌花的泌蜜高峰均为上午，下午降低，晚上最少。麻疯树的白昼访花昆虫数量显著高于夜间访花昆虫，白昼访花昆虫主要为蜂类，上午为活动高峰，夜间访花者种类主要为夜蛾,种类与数量均很少。套袋试验表明，白昼昆虫传粉的麻疯树的结果率与开放授粉接近，夜间昆虫传粉后麻疯树的结果率明显低于白昼传粉昆虫，但显著高于没有昆虫传粉。因此，白昼传粉昆虫为麻疯树最重要的传粉昆虫，夜间传粉者对麻疯树繁殖也做出一定的贡献。6.蚁类昆虫的传粉贡献在元谋、双柏两个试验点对蚁类访花频率进行观察，对蚁类携粉量与蚁类授粉后的柱头花粉落置量进行观测，通过隔离昆虫套袋试验对蚁类与有翅昆虫对麻疯树的繁殖贡献进行检测。结果表明，蚁类为麻疯树的最丰富的访花昆虫，在双柏与元谋分别占访花昆虫的71.03%与78.17%。在所有的蚂蚁中，黑头酸臭蚁是两个试验点唯一相同的蚂蚁种类，同时也是数量最丰富的蚂蚁，可能是对麻疯树的传粉贡献最大的蚂蚁。在两个试验点，不同种类蚂蚁携粉量差异显著，携粉量随着体型的增加而增加。开放式授粉、有翅昆虫授粉、蚂蚁授粉I、蚂蚁授粉II与蚂蚁授粉III五个处理的柱头花粉落置量差异显著。尽管蚂蚁授粉后的结果率与单果种子数量低于有翅类昆虫授粉，但结果率达60%，显著高于无昆虫授粉。由于有翅类昆虫在干热地区的生长与繁殖受限，可以充分利用数量丰富的蚂蚁为麻疯树提供授粉。更多还原

【Abstract】 Jatropha curcas L. is an important biodisel shrub in Southwestern China. The kernel of itsfruit is rich in fatty oil, an excellent raw material for biodisel. At present, J. curcas has beenplanted in a large scale in Southwestern, Southern China, especially in Southwestern China.Previous studies reported a few of its pollination biology, such as floral visitors, visitingbehavior and breeding system. In order to understand the intrinsic connection between floralcharacteristics of J. curcas and pollinators and pollinators, this paper observed the pollinatorsand their pollinating behavior at four sites, studied the visual and olfactory attractiveness offloral attractiveness to main pollinators, and tested the contribution of different pollinatorgroups to the female reproductive success of J. curcas. The results are summarized asfollows:1. Geographic distribution of pollinatorsThe study was investigated at four sites. The results showed that J. curcas wasgeneralized pollinated plant, with a range between34species and45species at each sites, and113species at four sites in total. Pollinators were divided into seven functional pollinationgroups including honeybees, solitary bees, ants, Diptera, Coleoptera, Lepidoptera andHemioptera. Pollinator composition is completely similar at function pollinator group, buthighly dissimilar at family, genus and species level among four sites. Pollinators distributedwidely in zoogeographical regions in the world, as well as in China. Thus, J. curcas couldattract diversified functional groups of pollinators and were generalized pollination plant.Pollinator composition was influenced by the inhabitation of J. curcas, while pollinators oftendistrubitued broadly both in the zoogeographical regions of world and that of China.2. Main pollinators and their foraging behaviorThe paper studied the abundance of visitors, predators, the floral reward, pollen grainscarried by pollinators, body part carrying pollen grains, pollination efficiency and preferencefor flower sex, then analyzed their effect on reproductive success of J. curcas. The resultsshowed that main functional pollination groups were honeybees, ants, Diptera and Coleoptera.Predators for visitors were spiders, mantis etc.. The most important reward for floral visitorswas nectar. All major functional groups carried pollen grains with them, and quantity ofpollen grains adhered to different body parts were different. Honeybees and Diptera only carried pollen grains of J. curcas, due to their flower constancy or cleaning off of body partfrequently, which played an important role on the homoscedasticity of all pollen grainsdeposited on its stigma from that of J. curcas. Major body part of pollination was basalproboscis for honeybees and Diptera, was abdominal for beetles. The quantities deposited ondifferent stigmas of female flower after single visit of A. cerena and C. megacephala weresignificantly different. Thus, more than one visit of A. cerena and C. megacephala wouldhelp enough pollination of female flower. A. cerena and A. florea preferred to male flowers,and C. megacephala did not show preference, while the preference of former pollinators mightcause low pollination rate of J. curcas. Thus, honey bees and Diptera were capable of carringover abundant, homogenous pollen grains, transfering pollen grains efficiently throughproboscis-touch pollination. However, pollination efficiency could be decreased by bothunbalanced pollen deposition among three stigmas of honey bees and preferrence of honeybees to male flowers.3. Visual attractiveness of floral characteristics to its pollinatorsThis paper observed the micro-characteristics of pollen and stigma, flower sizes of bothmale and female flowers, tested the effect of floral component, petal size and floral color onpollinators, and observed the floral display of inflorescence under drought stress. The resultsshowed that stigma of J. curcas was dry type, but pollen grain is rich in water and large-sizedin diameter which might help adherence and germination of pollen grain. Corolla diameter offemale flowers was larger than that of males while the diameter of stamen was larger than thatof pistils. There was no significant difference between the corolla tube length of male flowersand that of females, and between the length of stamen and pistil, which might help theconverting of pollen grains. Both male and female flowers could emit fragrance, mainly frompistil and ovary might increase the attractiveness of flowers to pollinators. Removing petalsor stamen could decrease the attractiveness of flower to honey bee and Diptera, whileremoving calyx did play any role on the attractiveness. Decreasing of petal size woulddecrease the attractiveness of honeybees and Diptera. Change of stamen color woulddecrease the floral attractiveness to honey bees, but did not to Diptera. Inflorescences underdrought stress showed protandry which showed small floral display of female flowers withinan inflorescence, and, therefore, might decrease the pollination rate of female flowers. Thus,flower of J. curcas attracted honey bees and Diptera through floral composition, petal sizes andpistil colour.4. Olfactory attractiveness of floral volatile to its pollinators Floral and foliage volatiles of J. curcas were collected by head space and离体, and thendetected, analyzed and identified. EAG responses of A. cerena to floral volatile of J. curcasand to different intensity of volatile were detected. Olfactory behavior responses of A. cerenaand C. megacephala to different odour source were detected. The results showed that themost abundant chemicals from flower and leave of J. curcas were ocimene and linalool,followed by aliphatic compounds. Floral and foliage volatile emitted most linalool in themorning, and emitted a little or did not emit linalool in the afternoon and at night. Similarly,opening inflorescence released most linalool, while unopen and opened inflorescences emittedlittle linalool. All tested floral volatiles elicited EAG response of A. cerena, while linalooland all fatty aldehydes elicited high EAG response. Dose response curves of EAG showedthat A. cerena response to the bottom dose of tested volatiles ranging from0.4μg to4μg.The EAG response of A. cerena increased with increased dose, and did not reach its saturationspot at maximum tested dose. Olfactory behavior response showed that A. cerena respondedstrongly to floral volatile of J. curcas, while C. megacephala showed little response. Thus,floral volatiles of J. curcas attracted A. cerana, and did not attract C. megacephala.5. Contribution of diurnal and nocturnal visitors to the pollinationI examined the contribution of diurnal and nocturnal insects to the pollination ofmonoecious J. curcas, through its floral biology, pollination ecology of J. curcas and foragingbehavior of potential pollinators at Shuangbai. Nectar production of both male and femaleflowers peaked in the morning, declined in the afternoon, and rapidly bottomed during thenight in all of their anthesis days. The diurnal visitors to the flowers of J. curcas are bees andflies, and the nocturnal ones are moths. Flowers received significantly more visits by diurnalinsects than by nocturnal ones. Through bagging flowers during night or day or both orexclusion, we compared fruit and seed production caused by diurnal and nocturnal pollinators.Both nocturnal and diurnal visitors were successful pollinators. However, flowers exposedonly to nocturnal visitors produced less fruits than those exposed only to diurnal visitors.Thus, diurnal pollinators contribute more to seed production by J. curcas at the study site.6. Ants contributed significantly to the pollinationFloral visitor assemblage and foraging behavior of ants were observed, pollen loadscarried by ants and deposited on stigmas were measured, and the contribution of ants to thefemale reproductive success of J. curcas through exclusion experiments were determined atShuangbai and Yuanmou. Ants were the most abundant pollinators, accounting for71.03% and78.17%of total visits at two study sites. Among different ant species, Tapinomamelanocephalum is always the most abundant and the only common ant species at two studysites, which might suggest its important role in the pollination of J. curcas. Pollen loadscarried by ants were significantly different among different species at two study site. Pollenloads carried by ants increased with increased body length. Pollen loads deposited on stigmaswere significantly different in the open group, winged only, ants only I, ants only II, ants onlyIII, respectively. Although the flowers exposed only to ants produced less fruit than thoseexposed only to winged visitors, ants alone resulted in almost60%fruit set. Thus, ants couldplay a major role in the pollination of J. curcas if winged insects are absent.更多还原