贮运温度对盆栽榕树落叶及抗性生理的影响

以盆栽榕树为试验材料,探讨不同贮运温度对盆栽榕树落叶及抗性生理的变化。结果表明,不同贮运温度对盆栽榕树落叶及抗性生理影响显著。与(16±1)℃及(19±1)℃比较,(10±1)℃及(13±1)℃的贮运温度能显著减缓叶片的细胞质膜透性、降低丙二醛(MDA)含量,提高过氧化物酶(POD)和过氧化氢酶(CAT)活性,增加可溶性糖和可溶性蛋白含量,延缓叶绿素的降解速度,落叶率低。在贮运36 d时,(10±1)℃和(13±1)℃贮运温度的落叶率均在16%以下,达到出口要求,而两者间的落叶率差异不显著。     

福建泉州榕属植物园林应用调查及合理利用对策

通过对福建省泉州市榕属植物在园林绿地中应用情况的调查,总结了该属植物较高的应用价值,并分析了应用中存在的问题和误区,提出合理利用及管养对策。     

Within-Crown Flowering Synchrony in Strangler Figs,and Its Relationship to Allofusion1

We studied flowering phenology at the level of individual branches within strangler fig trees to determine (1) whether branches bloomed asynchronously within trees and (2) whether asynchrony, if observed, could be ascribed to genetically different branches of mosaic trees (i.e., trees formed by spontaneous grafting of genetically different individuals) undergoing individual flowering cycles that were out of phase with each other. Although asynchrony was fairly common, it most often reflected individual branches failing to bloom during one flowering episode, then coming back to bloom in synchrony at the next episode. We detected fewer mosaic trees than expected, and found only a very weak suggestion that mosaic trees may show less within-tree synchrony than simple trees.     

Consequences of protecting flowers in a fig: a one-way trip for pollinators?

Abstract. Fig trees ( Ficus ) have closed inflorescences. Closure is an efficient protection of flowers against non-specialist predators and harsh external environmental conditions. Each Ficus species is pollinated by a single insect species, an agaonid wasp, capable of forcing its way through a bract-covered pore, the ostiole, to gain access to the flowers. Figs also provide oviposition sites for the wasps. The fig/pollinator interaction is a classic example of mutualism. It has been widely assumed that, once pollinators have entered a fig, oviposited and pollinated, they die trapped within the fig. In this paper, we present observations under natural conditions and results of field experiments on three very different fig species ( Ficus aurea Nutt., F. carica L. and F. microcarpa L.) showing that some pollinators do exit or try to exit from the fig after pollination and oviposition. Moreover, experimental results demonstrate that in at least one species ( F. carica ), the pollinator is able to oviposit successively in two different figs.
The frequency of re-emergences from figs after pollination varies among species and this may be related to variations in pollination dynamics depending on environmental constraints such as the abundance of trees and tree phenology. Several factors that may favour pollinators that leave figs after pollination and oviposition are discussed. They include competition between pollinators for oviposition sites, and minimising of the risk of vertical transmission of parasites and pathogens.     

Convergent evolution of agaonine and sycoecine (Agaonidae, Chalcidoidea) head shape in response to the constraints of host fig morphology

Abstract. Similar morphological adaptations have arisen independently across separate lineages within the fig wasps (Agaonidae, Chalcidoidea, Hymenoptera) in response to the extreme selective pressure provided by the morphological constraints of their host fig trees ( Ficus , Moraceae). Evidence is forwarded that supports the convergence of female head shape between two distinct fig wasp lineages, the Agaoninae (pollinators) and Sycoecinae (non-pollinators), utilizing the same host Ficus species (section Gagolychia ). In contrast to the vast majority of the non-pollinating fig wasps, that oviposit from the outside of the fig, the Agaoninae and Sycoecinae must negotiate the fig ostiole for internal oviposition, with the result that these independent lineages are simultaneously exposed to the selective pressure imposed by ostiolar morphology. Selection will favour a head shape that facilitates successful penetration of the fig cavity and this has resulted in the evolution of similar head shapes in the two lineages. Female head shape in both subfamilies was found to correlate with fig size, with elongate heads associated with large fig size. Given that ostiole bract arrangement is uniform within section Galoglychia , it appears that ostiole length may be the main factor contributing to head shape determination. The high degree of co-adaptation of head shape suggests that both the Sycoecinae and Agaoninae have coevolved with their host Ficus species.     

The ecology and evolution of the New World non-pollinating fig wasp communities

Abstract. We present data on several previously undescribed species from six genera of New World non-pollinating fig wasps. We show that many of these species have a negative effect on the reproductive success of both the pollinator wasps and the host figs. Our results suggest that the two most abundant genera of non-pollinating wasps, the Idarnes and the Critogaster , compete for the same pool of female flowers as the pollinating wasps in the Urostigma and Pharmacosycea figs, respectively. Wasps from the genus Aepocerus induce and develop within large galls, in the Urostigma figs. By draining resources from the fruit these wasps may have a detrimental effect on the production of pollinator wasps and viable seeds. Some of the species investigated are parasitoids of other non-pollinating species. We examine the importance of the various forms of spatial heterogeneity in the parasitism rate that can act to stabilise the host-parasitoid interaction. Finally, we discuss the factors underlying the large variation in the abundance and diversity of the non-pollinating wasps both among and within fruit crops.     

The Flight Heights of Chalcid Wasps (Hymenoptera,Chalcidoidea) in a Lowland Bornean Rain Forest: Fig Wasps are the High Fliers1

Tropical rain forests are characterized by their rich plant diversity and highly diverse insect faunas containing mainly rare species. Phytophagous and parasitoid insects utilizing such fragmented resources often must travel considerable distances to find suitable hosts. For small, weak‐flying insects, entry into the fast‐flowing air above the canopy can provide one way by which long‐distance dispersal is achieved. Using sticky traps placed at different heights in a lowland rain forest of Borneo, we compared the diurnal and nocturnal flight heights of chalcids, a group of mainly very small parasitoids and phytophages, to determine if the air above the canopy was used for dispersal. Most families were represented throughout the range of trap heights, including those above the general canopy. A higher proportion of individuals were trapped above the canopy at night than during the day. Fig wasps were exceptional in that they were trapped almost entirely above the canopy. They included species associated with host trees that do not fruit in the canopy, suggesting that these short‐lived, slow‐flying insects actively fly up above the canopy and then use the wind to passively carry them the long distances needed to reach their highly localized and ephemeral hosts. Once the fig wasps detect the species‐specific volatiles released by their host figs, they then may fly down into the canopy, where the lower wind speeds would allow them to fly actively upwind to their hosts.     

Floral constraint resulting from intersexual mimicry in a gynodioecious fig tree

Fig trees (Ficus: Moraceae) are pollinated by female fig wasps (Agaonidae) whose larvae develop inside galled flowers of unusual inflorescences (figs). Most fig trees also support communities of non‐pollinating fig wasps. Figs of different species display great size variation and contain tens to tens of thousands of flowers. Around one‐half the species of fig trees have the gynodioecious breeding system, where female trees have figs that produce seeds and male trees have figs that support development of pollinators. Mutual mimicry between receptive male and female figs ensures that pollinators enter female figs, even though the insects will die without reproducing, but the need to give no sex‐specific cues to the pollinators may constrain differences in size between receptive male and female figs. We compared relationships between inflorescence size and some measures of reproductive success in male and female figs of Ficus montana grown under controlled conditions in the presence of the pollinator Kradibia tentacularis and its main parasitoid Sycoscapter sp. indesc. Female figs that contained more flowers produced more seeds, but male figs did not increase the production of female pollinator K. tentacularis fig wasps in proportion of the flower number. Although more flowers were galled by the pollinators in male figs containing more female flowers, the high larval mortality caused by parasitism and nutritional limitation prevented the increase in the production of adult female offspring. Selection may favor the increase in flower numbers within figs in female plants of F. montana, but contrarily constrain this attribute in male plants.     

朱红毛斑蛾嗜食性的研究

通过野外调查和室内选择实验,研究了朱红毛斑蛾的食性。自然条件下,朱红毛斑蛾为害榕属植物中的小叶榕和垂叶榕,为害率分别为67.39%和47.61%。在T50时,朱红毛斑蛾对印度榕、对叶榕、无花果、黄葛树、高山榕、小叶榕和垂叶榕的平均取食量分别为0、0、0、0、0、8.62±1.6 cm2和3.79±1.8 cm2;平均取食选择指数分别为0、0、0、0、0、0.69和0.31,说明朱红毛斑蛾仅为害小叶榕和垂叶榕,且对小叶榕有明显偏好性。研究结果证明朱红毛斑蛾为寡食性害虫,提示在园林绿化过程中应尽可能避免选择易受害的单一树种大面积栽种。     

薜荔榕小蜂(Blastophaga pumilae Hill)与薜荔(Ficus pumila L.)的共生关系

榕属(Ficus)植物皆具隐头花序,我国有120种,分布很广。榕小蜂与榕树有着密切的共生关系。本文首次报道了我国此类动、植物的共生现象;发现了在同一个花序中雄花迟熟达一年的第一例植物;摸清了我国大陆新分布的薜荔榕小蜂的生活史;论述了发育的同步性、结构与功能的统一性。其内容可作为了解榕属植物的隐头花序与榕小蜂特殊的形态结构、生活方式、传粉过程及体现在其中的生钫进化辩证法则的代表。因取材于分布最广的薜荔,敬为相关学科的教学、科研提供了生动易得的倒证。文末提出尚待解决的问题。