水淹对三峡库区两种岸生植物秋华柳(Salix variegata Franch.)和野古草(Arundinella anomala Steud.)水下光合的影响

为了阐明水淹对三峡库区岸生植物秋华柳(Salix variegata Franch.)和野古草(Arundinella anomala Steud.)水下光合作用的影响,模拟三峡库区消落带水淹发生情况,考察了在不同水淹处理下秋华柳和野古草的水下光合.实验设置了对照(不进行水淹,常规供水管理)和2m深度水淹(植株置于水中,植株顶部在水面下2 m)2个不同的水淹深度和5、15、20、40 d和60 d等5个不同的水淹时间处理,采用Chlorolab-2液相氧电极(英国Hansatech公司生产)测定了在不同水淹时间和水淹深度处理下秋华柳和野古草的水下光合作用.实验结果表明: (1) 水淹60d后,秋华柳和野古草的存活率均为100%,而典型的陆生植物香樟和马唐分别在水淹40d和15d后全部死亡.(2) 在相同的水淹时间和水淹深度下,秋华柳和野古草的水下光合速率(放氧速率)显著高于典型的陆生植物(香樟(Cinnamomum camphora(L.) Presl.)和马唐(Digitaria sanguinalis (L.)Scop.)) (3) 在长期水淹的条件下,秋华柳和野古草仍具有水下光合的能力.在水淹60 d后,水淹2 m的秋华柳和野古草植株的水下放氧速率显著低于对照植株的水下放氧速率,但仍具有水下光合的能力,其水下光合速率分别为0.202 μmol · m-2 · s-1和0.139 μmol · m-2 · s-1.同时,研究也表明在水淹40 d和60 d后,秋华柳表现出比野古草强的水下光合能力.研究表明,秋华柳和野古草在存活率和水下光合方面对长期水淹表现出良好的适应性,是可以用于三峡库区消落区植被构建的优良植物物种.     

Isolation of microsatellite loci from spotted gum (Corymbia variegata), and cross‐species amplification in Corymbia and Eucalyptus

Corymbia variegata (spotted gum) is an important commercial hardwood timber species in Australia. Fourteen polymorphic microsatellite loci were isolated from C. variegata, with 3–5 alleles amplified in three individuals examined. Cross‐species amplification in Corymbia was successful for all primer pairs, while 10 loci (71%) were successfully transferred to at least one species in the closely related genus Eucalyptus.     

多异瓢虫食物消耗与利用与其猎物棉蚜的寄主植物种类相关

【目的】猎物质量和类型在捕食者食物选择、消耗及营养转化过程中起着重要作用,植物的营养质量影响植食者的营养质量,进而植食者作为捕食者猎物的营养质量。为进一步了解植物-猎物-捕食者三营养层的相互作用,研究了寄主植物对捕食者食物消耗与利用的影响。【方法】在室内评价了多异瓢虫Hippodamia variegata (Goeze) 4龄幼虫和雌成虫取食和利用 5种不同葫芦科植物上的棉蚜 Aphis gossypii Glover的效率。【结果】多异瓢虫4龄幼虫和成虫均对南瓜Cucurbita moschata var. melonaeformis上的蚜虫取食量最高,而对瓢葫芦Lagenaria siceraria var. gourda上的蚜虫取食量最低。4龄幼虫取食哈密瓜 Cucumis melo var. cantalupensis上的蚜虫时,其相对生长率、食物利用率和食物转化率均达到最大,而雌成虫在取食黄瓜Cucumis sativus和搅瓜Cucurbita pepo var. medullosa上的蚜虫时,其相对生长率不存在显著差异,在取食黄瓜、瓢葫芦和搅瓜上的蚜虫时,其食物利用率和食物转化率也不存在显著差异。因此,哈密瓜上的瓜蚜更适宜作为多异瓢虫4龄幼虫的猎物,而黄瓜、瓢葫芦和搅瓜上的瓜蚜更适宜作为成虫的猎物。【结论】寄主植物种类与多异瓢虫对棉蚜的捕食效率相关,该结论为进一步利用昆虫的食性对害虫进行控制奠定理论基础。     

Body weights of ruffed lemurs (Varecia variegata) in European zoos with reference to the problem of obesity

Qualitative observations in several European zoos revealed a high proportion of obese individuals in different species of lemurs. This phenomenon was examined in both subspecies of the ruffed lemur (Varecia variegata variegata and Varecia variegata rubra). Data on body weight were obtained from 43 animals in 13 European zoos and were compared with body weights of wild ruffed lemurs. The captive individuals’ mean weight was significantly higher than either of two different samples of wild V. variegata variegata. Using a weight‐based definition of obesity, 46.5% of the individuals in our sample were obese. Neither significant differences in body weight between the two subspecies nor between sexes could be found. Body weight did not correlate with age. The findings are discussed with reference to the feeding ecology of ruffed lemurs and their nutrition in captivity and to implications for captive breeding programs for this species. Zoo Biol 20:261–269, 2001. © 2001 Wiley‐Liss, Inc.     

捕食量和温度对麦长管蚜在多异瓢虫体内可测定时间的影响

为了方便准确评价麦田捕食性天敌对麦长管蚜 Sitobion avenae (Fabricius) 的控制作用,应用单克隆抗体及间接 ELISA 方法研究了捕食量和温度对麦长管蚜在多异瓢虫 Adonia variegata（Goeze）体内可测定时间的影响。结果表明：在不同的温度和捕食量下,麦长管蚜在多异瓢虫体内的降解中间产物曲线均为单峰型。温度对猎物的可测定时间有显著的影响,随着温度的上升,猎物的可测定时间不断缩短。特别是当温度达到 30℃时,猎物的降解速率迅速上升,其可测定时间只有 1.18 天。捕食量对猎物的可测定时间也有显著影响,随着捕食量的增加,猎物的可测定时间延长。在 25℃的条件下,当捕食量从 1 头蚜虫增加到 3 头蚜虫,可测定时间从 2.81 天延长到 4.25 天。     

Tracking Bat‐Dispersed Seeds Using Fluorescent Pigment1

Tracking the dispersal of seeds by fruit‐eating animals in tropical rain forests is crucial to further our understanding of plant–frugivore interactions and their impacts upon forest regeneration and plant population dynamics. We tested the feasibility of tracking bat‐dispersed seeds in a Philippine lowland rain forest with the help of fluorescent pigment. The powder was mixed with acetone and sprayed to ripe fruits of fig trees, i.e., Ficus septica and F. variegata. During nightly monitoring using a hand‐held ultraviolet lamp bat deposits (seed‐containing spat outs and feces) could successfully be detected. Distances and directions of deposit sites to the focal trees were recorded and seed shadow areas were analyzed. Bats dispersed most of the seeds less than 50 m away from the parent plants resulting in seed shadow areas < 0.30 ha in size. An in situ fruit preference experiment showed that fluorescent powder is unlikely to deter bats from feeding on ripe figs. In conclusion, the technique is simple, inexpensive, noninvasive, applicable to different fields of research and allows one to follow the fate of seeds from known sources.     

多异瓢虫成虫对枸杞木虱的捕食作用

【目的】为了测定多异瓢虫Hippodamia variegata(Goeze)成虫对枸杞木虱Paratrioza sinica Yang&Li的捕食作用。【方法】在室内测定了多异瓢虫的捕食功能反应、种内干扰、自身密度干扰、捕食偏好性,并通过罩笼试验研究多异瓢虫在田间对枸杞木虱的捕食效果。【结果】结果表明,多异瓢虫对枸杞木虱的捕食功能反应符合HollingⅡ型方程,对卵、1~2龄若虫、3~5龄若虫以及成虫的最大捕食量分别为80.4粒、410.0头、350.8头和102.5头。田间罩笼试验结果证明,在多异瓢虫成虫生长周期30 d内能使枸杞木虱总虫口密度下降85.4%;多异瓢虫对枸杞木虱成虫的搜寻效率a=0.8252为4种木虱虫态最佳,而对枸杞木虱卵处理时间Th=0.002283为4种木虱虫态中最佳;在100头/皿的猎物密度下多异瓢虫均能展现其最大捕食率,益害比参考值为1∶100。多异瓢虫对枸杞木虱的捕食作用受自身密度的影响显著大于种内干扰;在100头/皿混合猎物密度下,多异瓢虫更偏好木虱成虫,在300头/皿下,多异瓢虫更偏向于木虱若虫。【结论】研究表明,多异瓢虫是具有控制潜力的捕食性天敌,人工释放多异瓢虫成虫可有效防治枸杞木虱。     

PKs的生物学功能

PKs是最近发现的多功能分泌蛋白,由PK1和PK2组成.在不同的系统中,它们通过两个高度同源G-蛋白偶联受体发挥各种生物学功能.它们与神经和血管的形成以及免疫应答的调节有关,并且对生殖系统的正常生理和促性腺激素释放激素系统的发育都有很大的影响.     

Early embryogenesis in discoglossoid frogs: a study of heterochrony at different taxonomic levels

We studied the timing of the early development of the cranial neural crest, neural tube differentiation, somite formation and body elongation in the closely related frog species Discoglossus montalenti , Discoglossus galganoi , Discoglossus pictus , Bombina orientalis , Bombina variegata and Bombina maxima . Despite their different egg and embryo sizes, event pairing shows that there are only very few heterochronies among the three Bombina species and the three Discoglossus species in early developmental events. Instead, differences become apparent at the genus level (interpreted as phylogenetic signal). For example, the separation into a mandibular and a hyoid portion of cranial neural crest could be seen earlier in the Discoglossus than in the Bombina species when compared with the development of the neural tube. The development of the cranial neural crest streams also shifts (relatively) forward in time when compared with body elongation and somite formation in the Discoglossus species in contrast to the Bombina species. Comparisons with other species show that attempts to correlate heterochronies in early development with life history changes should take into account the possibility of a rather high evolvability, i.e. a high probability of convergence in the timing of these early events.