湿地松粉蚧夏季数量凋落的原因分析

利用生命表技术及其相应的控制指数分析方法,对新侵入害虫湿地松粉蚧Ｏｒａｏｅｌｌａａ－ｃｕｔａ（Ｌｏｂｄｅｌｌ）夏季数量凋落的某些因子进行了量化分析。结果表明：在广东南部的新侵入区,夏季高温引起的松梢迅速老化,上代为害以后引起的营养质量的变化、拥挤以及煤污病的严重发生等,均对湿地松粉蚧夏季种群数量的凋落有着明显的影响,其总的排除作用控制指数ＥＩＰＣ为４６．８９,如果排除这几个因子的作用,下代种群的数量将为当代的４６．８９倍。     

How do developmental and parental exposures to predation affect personality and immediate behavioural plasticity in the snail Physa acuta?

Individuals differ in personality and immediate behavioural plasticity. While developmental environment may explain this group diversity, the effect of parental environment is still unexplored—a surprising observation since parental environment influences mean behaviour. We tested whether developmental and parental environments impacted personality and immediate plasticity. We raised two generations of Physa acuta snails in the laboratory with or without developmental exposure to predator cues. Escape behaviour was repeatedly assessed on adult snails with or without predator cues in the immediate environment. On average, snails were slower to escape if they or their parents had been exposed to predator cues during development. Snails were also less plastic in response to immediate predation risk on average if they or their parents had been exposed to predator cues. Group diversity in personality was greater in predator-exposed snails than unexposed snails, while parental environment did not influence it. Group diversity in immediate plasticity was not significant. Our results suggest that only developmental environment plays a key role in the emergence of group diversity in personality, but that parental environment influences mean behavioural responses to the environmental change. Consequently, although different, both developmental and parental cues may have evolutionary implications on behavioural responses.     

Ecdysteroid glycosides from Sida rhombifolia L

Seven ecdysteroids, including the three new compounds 1-3, were isolated from Sida rhombifolia L. Their structures and configurations were determined by extensive spectroscopic techniques in combination with chemical derivatization. The four known compounds--ecdysone (4), 20-hydroxyecdysone (5), 2-deoxy-20-hydroxyecdysone-3-O-beta-D-glucopyranoside (6), and 20-hydroxyecdysone-3-O-beta-D-glucopyranoside (7)--are reported for the first time from this plant.     

拔毒散的化学成分及其抗炎活性研究

拔毒散(Sida szechuensis)为一种傣族传统的药用植物,常用于治疗诸疮肿毒、皮肤瘙痒、跌打损伤、刀枪伤等疾病。为研究拔毒散的化学成分及其体外抗炎活性,该研究采用硅胶柱色谱、Sephadex LH-20柱色谱、半制备HPLC等方法对其地上部分的化学成分进行分离纯化,通过理化性质和NMR等波谱数据鉴定化合物的结构,并用脂多糖(LPS)诱导的巨噬细胞(RAW 264.7)作为炎症模型,评价所分离化合物的抗炎活性。结果表明:从拔毒散乙醇提取物中共分离得到16个化合物,分别鉴定为kaempferol-3-O-β-D-glucopyranoside(1)、 kaempferol-3-O-rutinoside(2)、槲皮素(3)、20-hydroxyecdysone(4)、α-ecdysone(5)、22-deoxyecdysterone(6)、abutasterone(7)、pterosterone(8)、icariside E₅(9)、icariside E₃(10)、(+)-syringaresinol(11)、pinoresinol(12)、balanophonin B(13)、N-trans-feruloyl tyramine(14)、(-)-loliolide(15)、棕榈酸(16),其中化合物1-3、9-13、16首次从该植物中分离得到。抗炎活性测试结果表明,在50 μmol·L^-1的浓度下,化合物1、4、5无明显抑制NO生成作用,而化合物2、3、6-16均能在不同程度上抑制NO生成,其中化合物2、3、11-14具有较强的抗炎活性,其IC₅₀值分别为18.63、40.76、21.46、14.32、16.82、42.31 μmol·L^-1。该研究结果丰富了拔毒散的化学成分,明确了其具有抗炎效果的物质基础,验证了其传统用途的科学性,为其进一步在医药领域的开发利用提供了新思路及科学依据。     

Classical biological control program for the mealybug Oracella acuta in Guangdong Province,China

Abstract The mealybug Oracella acuta, native to the southeastern US, was accidentally introduced into slash pine plantations in Guangdong Province in China in 1988. A classical biological control program was initiated in 1995, and the parasitoids Allotropa oracellae, Acerophaus coccois, and Zarhopalus debarri were imported from the US. A total of 19 972 parasitized mealybugs were shipped to China from 1996–2004, from which 15 430 wasps emerged, 12 933 of which were the three target species. Efforts to establish a mass-rearing program for the parasitoids in China failed. Five field release sites were established, and 6 020 parasitoids were released. Only 118 individuals of the three imported species were collected during establishment checks, although several wasps were collected 1–2 years after the last parasitoid release. Over 2 000 Anagyrus dactylopii, a cosmopolitan parasitoid, emerged from the parasitized mealybugs collected, a majority from the Taishan area near the site of the original introduction of O. acuta. To date the imported parasitoids have failed to establish, and natural enemies have not noticeably reduced mealybug populations.     

Direct shoot regeneration from nodal explants of <Emphasis Type="Italic">Sida cordifolia</Emphasis> Linn

A method was developed to initiate multiple shoots from mature nodal explants of Sida cordifolia Linn. High frequency of regeneration was achieved on Murashige and Skoog (MS) medium supplemented with 2.0 mg l⁻¹ 6-benzylaminopurine, 0.5 mg l⁻¹ α-naphthalene acidic acid, 1.0 mg l⁻¹ adenine sulfate, and 10% (v/v) coconut milk. Multiple shoots were initiated within 21 d and the above media was capable of inducing the formation of more than 20 shoots from each explant. Regenerated shoots were successfully rooted on half-strength MS medium supplemented with 2.0 mg l⁻¹ indole-3-butyric acid and 3% (w/v) sucrose. Rooted plantlets were established in soil. The regenerated plantlets showed no morphological differences from the parent material. This protocol could be useful for germplasm conservation, cultivation, and genetic improvement of S. cordifolia.     

Marking hard-shelled gastropods: tag loss, impact on life-history traits, and perspectives in biology

Abstract. Individual marking has long been used in many fields of biology. However, capture–mark–recapture (CMR) studies are not evenly distributed among taxonomic groups, with most studies focusing on vertebrates. For example, a limited number of studies have been conducted in gastropods, in sharp contrast to their important role as biological models or exploited natural resources. The lack of standard, validated marking techniques certainly contributes to the limited use of CMR. In this article, we evaluate two fundamental requirements for a marking technique to be suitable, i.e., tag loss (two experiments) and impact on life-history traits (survival, growth, and fecundity, in three experiments). Five marking techniques for hard-shelled gastropods were tested in the freshwater snail Physa acuta (Pulmonata). The tag-loss rate per month was lower for glued plastic marks (0.01) than for paint marks (0.03–0.07), and the tag-loss rate varied among colors (gouache paint). Under laboratory conditions, the life-history traits were not significantly affected by marking. We thus recommend using glued plastic marks for long-term studies, and paint marks for mass marking, with double marking to account for tag-loss rate. Based on an extensive literature survey, we also review current CMR practices in gastropod studies and suggest general improvements that would prove useful in both this group and invertebrates in general.     

Neuroprotective effect of polysaccharide separated from Perilla frutescens Britton var. acuta Kudo against H2O2-induced oxidative stress in HT22 hippocampus cells

This study was carried out to evaluate the neuroprotective activity of polysaccharide extracts isolated from Perilla frutescens (PEPF) in H₂O₂-treated HT22 hippocampus cells. The PEPF treatment was found to increase the anti-oxidant activities of HT22 hippocampus cells. PEPF treatment resulted in a significant protection of HT22 hippocampus cells against H₂O₂-induced neurotoxicity, this protection ultimately occurred through an inhibition of ROS-mediated intracellular Ca²⁺ levels leading to MAPKs and NF-κB, as well as the accumulation of PI3K/AKT and Nrf2-mediated HO-1/NQO1 pathways. Furthermore, PEPF not only decreased the expression of Bax, cytochrome c, and cleaved caspases-3, -8, and -9, but also increased the expression of PARP and Bcl-2 in the H₂O₂-treated HT22 hippocampus cells, which overall contributed to the neuroprotective action. PEPF retains its mitochondrial membrane potential and reduces the elevated levels of sub-G1 phase and apoptotic morphological features induced by H₂O₂. It also reduces the malondialdehyde levels and enhances the intracellular SOD activity.     

The influence of self‐fertilization and grouping on fitness attributes in the freshwater snail Physa acuta: population and individual inbreeding depression

The genetic structure, selfing rate and inbreeding depression of the hermaphroditic freshwater snail Physa acuta were jointly analysed in a population near Montpellier, France. Allozymic markers revealed moderate gene diversity (0.138), and no heterozygote deficiency. The mean outcrossing rate, estimated by using progeny arrays, was 0.9, with substantial variation among families. This also suggests that the number of fathers among outcrossed offspring of a given mother is low. Inbreeding depression was estimated over more than one generation using 83 first‐laboratory‐generation (G₁) families. The main parameters measured were parental (G₁) fecundity, offspring (G₂) survival and fecundity. Size and growth were also monitored. Parental fecundity was analysed under several conditions (isolation, pair and quadruplet outcrossing). The self‐fertilization depression, including parental fecundity, offspring survival and fecundity, was about 0.9 at the population level. The genetic data obtained in the same population indicate a value of about 0.3 using Ritland’s (1990) technique, suggesting that the depression over the whole life‐cyle might be even higher than 0.9. Grouping affected neither fecundity nor self‐fertilization depression. Substantial variation in depression for survival was detected among individuals, from no survival in some selfed families to better survival than that of outbred families in others. The overall result (outbred population structure, high outcrossing rate and high self‐fertilization depression) is consistent with what is expected in large outcrossing populations in which inbreeding depression is maintained by mutation‐selection balance.