南瓜单粒花粉可溶蛋白等电聚焦研究

利用显微操作方法对南瓜单个花粉可溶蛋白成功地进行了等电聚焦,获得了清晰的电泳谱带。分析其谱带表明,同一植株同一朵花上的花粉之间存在着蛋白谱带的差异,统计结果显示其按１：１的孟德尔规律分离。单花粉蛋白等电聚焦结合显微镜操作技术对于遗传育种和发衣生物学研究具有重要的应用前景。     

Assessing the lifetime consequences of plant-animal interactions for the perennial herb Lathyrus vernus (Fabaceae)

Interactions with animals are potentially important in shaping the life histories of plants. However, we still largely lack the quantitative information that is necessary to compare plant-animal interactions and plant life histories. This is because most studies have focused on only a single interaction and a single component of fitness. This review suggests a protocol for how plant-animal interactions, as well as other, interactions can be quantitatively investigated.I review results from the forest herb Lathyrus vernus to examine how plant performance is influenced by mollusc damage of shoot buds, vertebrate grazing, leaf damage, pre-dispersal seed predation, flower herbivory and pollinator visitation. More specifically I ask: (1) What are the effects of these interactions on components of plant fitness? (2) How do such effects translate into total fitness? (3) Do trade-offs among components of plant fitness influence the net effect of animals? (4) Are antagonistic and mutualistic interactions influenced by the same plant traits?The results illustrate why it is often necessary to monitor plants over several seasons and over all life cycle phases to assess the total effects of environmental factors. In L. vernus many components of fitness were affected by multiple interactions with animals. A large proportion of these effects was carried over to subsequent seasons and could only be detected after one or two seasons. Assessing the effects on overall performance in perennial plants is particularly difficult because fitness components have very different influence on total fitness. The matrix model approach used to estimate the effect of herbivores, seed predators and pollinators on L. vernus provides one possible way to make such assessments for organisms with complex life cycles. The results show that the cryptic damage of emerging shoots has the largest negative effects on total fitness. Correlations between different components are an essential feature of many life histories and must be incorporated into demographic models if we want to assess the net effect of environmental factors. In L. vernus costs of reproduction were present and demographic modelling showed that the positive effects of an increased seed production after additional hand-pollination on total fitness was completely offset by poorer performance in the following year. Lastly, this study provides an example of how optimal trait values can be assessed when traits influence several fitness components and several interactions. In L. vernus a higher number of flowers was correlated to both an increased fruit set and an increased risk of grazing damage and these effects were, in turn, carried over to the next season. The results clearly illustrate the limitations of inferences about phenotypic selection pressures that are based on single fitness components or single interactions.Taken together the results for L. vernus show that the selective pressure constituted by a given amount of animal interference is highly dependent on the context, in terms of both plant life history and other interactions. A life cycle approach like the one outlined in this study may avoid several problems and provide the basis for assessments of the total effects of animals on plants. Such an approach must be based on in-depth studies of plants.     

应用SRAP标记绘制88份南瓜属种质资源DNA指纹图谱

为了给南瓜属种质资源鉴定和分类提供分子生物学依据,本研究采用SRAP分子标记技术与DNAMAN指纹图谱绘制软件对88份南瓜属种质资源(包含美洲南瓜、中国南瓜、印度南瓜)进行分子指纹图谱绘制。结果表明:35对SRAP多态性引物共扩增出499条清晰条带,其中多态性条带438条,多态性条带比率高达87.8%。根据扩增出的条带成功绘制出88份南瓜属种质资源的DNA指纹图谱,每一份种质都具有其独特的分子身份证,使得每份种质均可被区别开来。其中,多态性最好的引物是E5EM8,可以同时绘制72份南瓜属种质资源的指纹图谱。所有供试材料用5对多态性SRAP引物即可全部区别开来。研究表明,SRAP分子标记技术可成功地绘制南瓜属种质资源DNA指纹图谱。本研究对南瓜属种质资源鉴别、分子数据库构建及品种权保护具有较重要的意义。     

Pollinators as mediators of top-down effects on plants

This paper explores the idea that predators may disrupt plant–pollinator relationships and consequently inhibit reproduction in flowering plants. Amidst growing evidence that predators influence plant–pollinator interactions, I suggest that such pollinator‐mediated indirect effects may be a common feature of terrestrial communities, with implications for research into top‐down effects and pollination ecology. Experimental evidence of such an effect from a riparian system in northern California is provided, where crab spiders decreased seed production in inflorescences of the invasive plant Leucanthemum vulgare by reducing the frequency and duration of floral visits by pollinating insects.     

Testing for mycorrhizal fungi-plant-ant indirect effects

Abstract

Recent work has demonstrated indirect effects between mycorrhizal fungi and insect herbivores and pollinators. The existence of indirect effects between mycorrhizal fungi and protection-for-food mutualists, such as extrafloral nectar-foraging ‘bodyguard ants’, is unknown. In this study, we examined the potential for indirect effects of arbuscular mycorrhizal fungi on aggressive ant bodyguards, mediated by changes in the expression of extrafloral nectaries of a shared host plant. We found that mycorrhizal plants grew larger and produced more extrafloral nectaries compared to their non-mycorrhizal counterparts. The difference in the number of nectaries between mycorrhizal and non-mycorrhizal plants, however, was too small to elicit differences in ant attendance. In spite of the lack of a significant indirect effect of mycorrhizal fungi on ant attendance, mycorrhizal plants suffered damage to a significantly greater proportion of their leaves compared to non-mycorrhizal plants. This result likely stems from other (non-ant-mediated) indirect effects of mycorrhizal fungi on herbivores.     

Effects of lindane and deltamethrin on zooplankton communities of experimental ponds

Two insecticides, lindane (321 µg l^–1) and deltamethrin (13 µg l^–1) were employed in a four mesocosm experiment (two ponds of 10 m³ and two of 16 m³) to asses the impact of water pollution by pesticides. Resistance of the different zooplankton species was variable and depended upon both the group and the insecticide concentration. No effect of lindane was observed on macrozooplancton such as Cladocera and Copepoda. In the deltamethrin-treated pond, all species of zooplankton were found dead a day after the treatment. The microzooplankton (Rotifera and copepod nauplii) were highly susceptible to both insecticides. Although the larvae of Chaoborus were present in the ponds after the treatments, their density decreased (less than 1 individual l^–1). The elimination of filter-feeding zooplankton by deltamethrin was followed by an increase of the concentration of chlorophyll a in the post-treatment period. Two months later the original zooplankton population recovered, with the addition of a new and dominant species: Ceriodaphnia reticulata.     

Correspondence between rates of host plant consumption and responses to the Acalymma vittatum male-produced aggregation pheromone

Abstract In field studies, wind-directed traps were used to investigate the resource-based properties of the male-produced aggregation pheromone of Acalymma vittatum (F.) (Coleoptera: Chrysomelidae). Responses to early season overwintered field-collected male A. vittatum without food were compared with those feeding on pollen, and in turn these were compared with those feeding on cucurbit seedlings. These comparisons were modelled after transitions as they would occur at the initiation of A. vittatum host plant colonization.
In another experiment, colony-reared male A. vittatum that had been fed only near isogenic lines of potted cucumber ( Cucumis sativus ) seedlings that either lacked or contained cucurbitacin were placed as bait in the traps. Using the inverse relationship, which is understood for A. vittatum , between previous exposure and the phagostimulant response to cucurbitacin, rates of foliage consumption could be manipulated. The interaction between relative rates of host plant consumption of the males used as lures and responses to the pheromone could thus be tested. The use of A. vittatum reared entirely without dietary cucurbitacin as bait also enabled evaluation of the potential role of cucurbitacin in pheromone biosynthesis. Trap responses were closely correlated with the rates of feeding of the beetles in the trap lures, but cucurbitacin was neither a precursor nor a prerequisite for the pheromone. Implications for early season field colonization and the adaptive significance of this pheromone are discussed.     

大量元素胁迫下南瓜化感作用研究

研究采用水培实验、生物测试及室内分析相结合的方法,研究在不同大量元素(N、P、K、Ca、S、Mg)营养胁迫下幼苗期南瓜根系分泌物及其提取物对南瓜幼苗生长的化感作用。结果表明：南瓜具有自毒作用,不同大量营养元素胁迫对其胚根和胚芽生长均产生了抑制作用。不同的营养条件对其根系分泌物的影响不同,营养元素的合理搭配可以减轻自身的自毒作用。南瓜根系分泌物经乙酸乙酯提取的活性有机物埘南瓜胚根牛长亦表现出抑制作用,且抑制作用程度较大。南瓜幼苗期根系十物质水浸液巾存在着抑制南瓜幼苗生长的化感物质：筛选出南瓜根系分泌物对自身幼苗生长产生抑制作用最弱的大量元素水平优化组合,为南瓜的营养胁迫机理提供依据。     

Mechanisms of plant defense against insect herbivores

Plants respond to herbivory through various morphological, biochemicals, and molecular mechanisms to counter/offset the effects of herbivore attack. The biochemical mechanisms of defense against the herbivores are wide-ranging, highly dynamic, and are mediated both by direct and indirect defenses. The defensive compounds are either produced constitutively or in response to plant damage, and affect feeding, growth, and survival of herbivores. In addition, plants also release volatile organic compounds that attract the natural enemies of the herbivores. These strategies either act independently or in conjunction with each other. However, our understanding of these defensive mechanisms is still limited. Induced resistance could be exploited as an important tool for the pest management to minimize the amounts of insecticides used for pest control. Host plant resistance to insects, particularly, induced resistance, can also be manipulated with the use of chemical elicitors of secondary metabolites, which confer resistance to insects. By understanding the mechanisms of induced resistance, we can predict the herbivores that are likely to be affected by induced responses. The elicitors of induced responses can be sprayed on crop plants to build up the natural defense system against damage caused by herbivores. The induced responses can also be engineered genetically, so that the defensive compounds are constitutively produced in plants against are challenged by the herbivory. Induced resistance can be exploited for developing crop cultivars, which readily produce the inducible response upon mild infestation, and can act as one of components of integrated pest management for sustainable crop production.     

应用SRAP标记分析金丝瓜（Cucubitapepo L.）种质资源遗传多样性与亲缘关系

本研究应用SRAP分子标记技术对56份金丝瓜和32份南瓜属（包括西葫芦美洲南瓜、中国南瓜、印度南瓜）种质资源遗传多样性与亲缘关系进行分析。结果表明：（1）从285对SRAP引物中共筛选出50对多态性引物对供试品种基因组DNA进行PCR扩增,获得713条清晰可辨的标记,其中多态性条带634条,多态性比率达88.92%,说明出南瓜属种间遗传多样性较丰富;（2）在56份金丝瓜品种中,共扩增出586条清晰可辨条带,多态性条带350条,多态性比率为59.73%,说明金丝瓜品种间的遗传相似性较高;（3）通过分子聚类分析可将供试金丝瓜品种划分为5个亚类群。金丝瓜与西葫芦美洲南瓜的亲缘关系较近,与中国南瓜的亲缘关系较远,而与印度南瓜的亲缘关系最远;根据分子聚类分析结果证实初步鉴定应可以明确将金丝瓜划归为南瓜属中西葫芦美洲南瓜的一个变亚种。