荒漠珍稀灌木半日花种群数量动态的谱分析

依据不同坡位的半日花（Helianthemum ordosicum）种群的野外样方调查数据,运用谱分析数学方法,对其种群数量动态变化进行了分析研究。结果表明：在以地径级差划分龄级的基础上,半日花种群天然更新过程的动态是通过半日花不同龄级的株数分布波动而表现的。不同坡位半日花种群的数量动态过程受基波影响最明显,并且波动还表现出明显的中、小周期。不同坡位种群均存在基本周期1／2的12～15mm地径增量的中等长度的周期波动,以及2．00～6．25mm地径增量的小周期波动。这种中、小周期波动与环境压力、种间竞争及自身生理特性等有关。由于不同坡位的生境条件不同,表现为从坡下部到坡上部,半日花种群数量变动的波动小周期（地径增量表型）逐渐缩短。人为干扰对不同坡位半日花种群动态的波动产生影响。半日花种群数量动态变化的这种周期性的波动可使半日花种群的自我稳定性得以维持与延续。     

Effect of drought stress on growth and water relations of the mycorrhizal association Helianthemum almeriense-Terfezia claveryi

 Plants of Helianthemum almeriense were micropropagated on MS medium and inoculated in vitro with Terfezia claveryi mycelium on MH medium and vermiculite. Mycorrhizal (M) and non-mycorrhizal (NM) plants were subjected to a drought stress period of 3 weeks in greenhouse conditions with the soil matric potential maintained at –0.5 MPa. Drought stress did not affect the amount of mycorrhizal colonization. The survival rate of M plants at the end of the drought stress period was higher than that of NM plants. The water potential was higher in M plants than in NM plants by 14% in well-watered and 26% in drought-stressed plants. Transpiration, stomatal conductance and net photosynthesis were higher in M plants than in NM plants. Transpiration was 92% higher in M plants than in NM plants under drought-stress conditions and 40% when irrigated. Stomatal conductance was 45% and 14% higher and net photosynthesis 88% and 54% higher, respectively, in M than in NM plants. Drought-stressed M plants accumulated more N, P and K than drought-stressed NM plants. Reduced negative effects of drought stress on H. almeriense by the desert truffle T. claveryi could be ascribed to specific physiological and nutritional mechanisms, suggesting that this mycorrhizal symbiosis aids adaptation to arid climates. Accepted: 7 July 2000     

荒漠珍稀灌木半日花种群的年龄结构与生命表分析

根据对不同坡位的半日花种群的调查资料,分析了其年龄结构,编制了静态生命表,分析了存活曲线和死亡率曲线、损失度曲线,并利用生存分析理论进行了函数分析。结果表明：不同坡位的半日花种群存在下降趋势。幼龄级和老龄级个体少,中龄级个体多。不同坡位的半日花种群密度存在差异,坡上部种群密度最大,坡下部最小,坡中部居中。不同坡位半日花种群在Ⅰ龄级时期望寿命达到最大,并在Ⅶ、Ⅷ龄级时期望寿命出现波动;不同坡位的半日花种群的存活曲线整体上趋于Deevy Ⅱ～Ⅲ型之间;在第Ⅵ~Ⅷ龄级半日花种群死亡率较高,且坡中部和坡下部种群死亡率峰值比坡上部种群滞后一个龄级。生存分析引入生命表中的4个函数能较好地说明不同坡位半日花种群的结构和动态变化。     

昆虫资源利用及其产业化进展

主要从食用昆虫、饲用昆虫、药用昆虫、工业原料昆虫、传粉昆虫、观赏娱乐昆虫、天敌昆虫、环保昆虫以及昆虫生物反应器和昆虫在仿生学上的应用等方面全面综述了昆虫资源的利用及其产业化进展.     

宁夏珍稀濒危植物半日花种群结构和点格局分析

半日花是国家二级珍稀濒危植物,其种群数量日益减少,分布区破碎化。以宁夏新记录物种半日花为研究对象,分析在沙地和砾石质两种生境下半日花种群结构、各龄级的空间分布格局及关联性。结果表明: 宁夏青铜峡地区半日花个体主要集中在龄级Ⅲ,种群年龄结构呈倒三角形,种群正在衰退。种群空间分布格局与不同龄级间空间关联性受生境条件的影响较大,并且对空间尺度表现出很强的依赖性,与沙地生境相比,砾石质生境中半日花种群更趋向于聚集分布,各个龄级之间的正相关性也更明显,这种差别与两种生境的环境条件和群落结构有关。半日花种群中幼龄个体(龄级Ⅰ和龄级Ⅱ)具有相互依赖的生态关系。     

Insects on the brink of a major discontinuity

Population surges and local extinctions are not uncommon among insects. In response to climatic changes in the past, insects have often shifted their ranges. This long-term range shifting and the vagaries of short-term weather makes reserve selection unrealistically rigid for many species. Although some insect species are surviving in reserves, others have disappeared from such small areas because of adverse weather. In contrast, many other insects depend on localized disturbance for survival. In response to anthropogenic disturbance, some native insects have become more abundant and widespread, such as Orthoptera in response to grazing and burning, and some Odonata in response to aquatic weeds and water impoundment. The effect of some exotic invasive insects on some native ecosystems is of major concern. Human-induced insect population crashes and species extinctions are becoming more common and widespread, and exacerbated by the synergistic effect of the various local impacts with global changes. A major insect population and species extinction discontinuity is beginning to take place. Yet, there is also an increase in range and abundance of some other insects. The world is becoming increasingly species-poorer and more homogenous in its insect fauna.     

四川王朗国家级自然保护区昆虫生物多样性初步研究

根据植被类型与海拔的变化,在王朗自然保护区选择了5个不同生境作为监测点.分别于2007年7、8、10月,2008年4月,对选定的监测对象进行采集,共采集标本24 876头,1000余种,隶属于3目7科,其中优势种群为尺蛾科、夜蛾科、姬蜂科、步甲科,其个体总数分别占69.51%、23.23%、5.03%、1.9%;鳃金龟科、叩头甲科以及瓢甲科仅占了0.33%.利用物种丰富度指数(S)、多样性指数(H′)、均匀度指数(J)对不同的群落进行统计,发现各监测对象的多样性随着时间与空间的变化呈现出不同的变化趋势.     

河南芝麻授粉昆虫初步调查

为了清楚了解芝麻花授粉昆虫种类、昆虫的授粉规律和授粉时间,2009年对河南省平舆县高杨店乡的13个样点芝麻花授粉昆虫进行调查,采集到授粉昆虫标本65份.经过整理鉴定,芝麻花授粉昆虫共计5目14科25种.其中,蜜蜂占授粉昆虫的92%,是大田芝麻主要的授粉昆虫.蜜蜂授粉出勤高峰出现在8:00～8:50和18:00～18:50.     

Lethal Effects of Helianthemum lippii (L.) on Acanthamoeba castellanii Cysts in Vitro

Acanthamoeba spp. commonly cause Acanthamoeba keratitis which is typically associated with the wear of contact lenses. Therefore, finding an economic, efficient, and safe therapy of natural origin is of outmost importance. This study examined the in vitro lethal potential of ethyl acetate and methanol extracts of Helianthemum lippii (L.) (sun roses) against Acanthamoeba castellanii cysts isolated from patients with amoebic keratitis. Both extracts proved to be potent as regard to their lethal effects on A. castellanii cysts with comparable results to chlorhexidine. The ethyl acetate was more promising with cumulative lethality. It showed a highly significant lethal percentage along the duration of treatment. The analysis of the more potent ethyl acetate extract revealed the presence of 2.96 mg/100 g of total phenolics, 0.289 mg/100 ml of total flavonoids and 37 mg/100 mg of total tannins which highlighted their phytomedicinal role.     

Phytochemical Profile and Biological Activities of Helianthemum canum l. baumg. from Turkey

In the current study, antioxidant, antibacterial activities, and the phenolic compositions of extracts from Helianthemum canum L. Baumg . (Apiaceae) aerial parts were investigated for the first time. The H . canum was extracted with 70% methanol (HCM eOH ) and water (HCW ). Both extracts were determined by total phenolic contents (3 mg/ml), flavonoids (1.5 mg/ml), flavonols (1.5 mg/ml), qualitative–quantitative compositions, iron (II ) chelation activities (0.1 – 5 mg/ml), free radical scavenging activities (DPPH ^?: 0.01 – 0.6 mg/ml and ABTS ^+?: 0.125 – 0.5 mg/ml) and the effect upon inhibition of β ‐carotene/linoleic acid co‐oxidation (1 mg/ml). The peroxidation level was also determined using the thiobarbituric acid method (0.01 – 1.5 mg/ml). The results of the activity tests given as IC ₅₀ values were estimated from non‐linear algorithm and compared with standards. Antibacterial activities of extracts and standards were evaluated against Gram‐ negative and ‐positive ten standard strains using disc diffusion and broth microdilution methods. The MIC results (312.5 – 2500 μg/ml) against tested microorganisms varied from 625 to 2500 μg/ml. In HPLC analysis, 3,5‐dihydroxybenzoic acid was found as the main substance in both extracts. These results showed that HCM eOH was richer in phenolic compounds (284.13 ± 0.30 mg GAE /g extract) from HCW (244.55 ± 0.35 mg GAE /g extract)_. In conclusion, H . canum extracts showed in vitro antibacterial and antioxidant activities.     

昆虫的化学感觉机理

昆虫是通过化学感觉器与其周围环境中的大量化学信息发生联系的。通过特定的化学感觉机制 ,昆虫可感知来自种内和种间 ,以及无机环境中的各种化学信息 ,并由此而作出相应的行为反应 ,从而为其自身寻找适宜的食物、配偶以及生存与繁殖场所 (如躲避天敌、避免或减少竞争等等 ) ,达到最大的繁殖成功。阐明昆虫的化学感觉机理 ,不仅可在理论上进一步加深对昆虫与植物、昆虫与昆虫相互关系的了解 ,而且可在实践上为开发害虫治理的新途径提供理论指导。本文将根据目前的最新研究成果 ,主要就昆虫的化学感觉机理 ,包括嗅觉和味觉机理作一综述 ,以期…     

Strong conservatism of floral morphology during the rapid diversification of the genus Helianthemum

Premise

Divergence of floral morphology and breeding systems are often expected to be linked to angiosperm diversification and environmental niche divergence. However, available evidence for such relationships is not generalizable due to different taxonomic, geographical and time scales. The Palearctic genus Helianthemum shows the highest diversity of the family Cistaceae in terms of breeding systems, floral traits, and environmental conditions as a result of three recent evolutionary radiations since the Late Miocene. Here, we investigated the tempo and mode of evolution of floral morphology in the genus and its link with species diversification and environmental niche divergence.

Methods

We quantified 18 floral traits from 83 taxa and applied phylogenetic comparative methods using a robust phylogenetic framework based on genotyping-by-sequencing data.

Results

We found three different floral morphologies, putatively related to three different breeding systems: type I, characterized by small flowers without herkogamy and low pollen to ovule ratio; type II, represented by large flowers with approach herkogamy and intermediate pollen to ovule ratio; and type III, featured by small flowers with reverse herkogamy and the highest pollen to ovule ratio. Each morphology has been highly conserved across each radiation and has evolved independently of species diversification and ecological niche divergence.

Conclusions

The combined results of trait, niche, and species diversification ultimately recovered a pattern of potentially non-adaptive radiations in Helianthemum and highlight the idea that evolutionary radiations can be decoupled from floral morphology evolution even in lineages that diversified in heterogeneous environments as the Mediterranean Basin.     

昆虫的NF-kB信号通路

昆虫NF-kB信号通路由toll和imd两条通路组成,通过转录因子NF-kB作用于靶标基因kB位点,而调节抗菌活性物质的表达。大量实验表明它能够被细菌、真菌和病毒的侵染所激活,在昆虫体液免疫中发挥着主要作用。现就昆虫的NF-kB信号通路的主要信号元件等进行综述。     

Breeding system, flower visitors and seedling survival of two endangered species of Helianthemum (Cistaceae)

BACKGROUND AND AIMS: Helianthemum marifolium and H. caput-felis are two endangered plant species of the western Mediterranean. Several aspects of the reproduction of both species were examined to determine whether their rarity could be related to factors causing reproductive limitation. METHODS: The flowering and fruiting phenology of both species in two non-sympatric island populations (Mallorca, Balearic Islands, western Mediterranean) were compared. Hand-pollination experiments were conducted to determine their fruit and seed production under different pollen sources. The composition of the pollinator assemblage and the effect of temporal variation and sun exposure on reproductive output and seedling survival were also investigated. KEY RESULTS: Flowering periods were longer for H. marifolium than for H. caput-felis in the populations studied. Helianthemum marifolium is mostly an outbreeder, i.e. fruit and seed set was three-fold higher when pollen came from other plants. In H. caput-felis, neither fruit nor seed set was affected by pollination treatments. Flower visitors were more diverse for H. caput-felis than for H. marifolium. In both species, most floral visits were made by hymenopterans. The total number of pollinator visits varied significantly between years, decreasing more than two-fold from 2001 to 2002, in both species. In agreement with its outbreeder character, variation in reproductive output between years was also observed in H. marifolium. It showed a 50 % decrease in fruit set in 2002, a pollinator-poor year. Finally, seedling survival increased three- to six-fold from 2001 to 2002. A correlation between seedling size and survival had also been detected. CONCLUSIONS: Reproductive limitations were detected for neither species (i.e. fruit and seed set, pollination service and seedling survival on natural populations). Hence, the increasing rarity of these two species is probably a direct result of the destruction of their habitat.     

Reconstruction of the spatio-temporal diversification and ecological niche evolution of Helianthemum (Cistaceae) in the Canary Islands using genotyping-by-sequencing data

Background and AimsSeveral biogeographical models have been proposed to explain the colonization and diversification patterns of Macaronesian lineages. In this study, we calculated the diversification rates and explored what model best explains the current distribution of the 15 species endemic to the Canary Islands belonging to Helianthemum sect. Helianthemum (Cistaceae).MethodsWe performed robust phylogenetic reconstructions based on genotyping-by-sequencing data and analysed the timing, biogeographical history and ecological niche conservatism of this endemic Canarian clade.Key ResultsOur phylogenetic analyses provided strong support for the monophyly of this clade, and retrieved five lineages not currently restricted to a single island. The pristine colonization event took place in the Pleistocene (~1.82 Ma) via dispersal to Tenerife by a Mediterranean ancestor.ConclusionsThe rapid and abundant diversification (0.75–1.85 species per million years) undergone by this Canarian clade seems the result of complex inter-island dispersal events followed by allopatric speciation driven mostly by niche conservatism, i.e. inter-island dispersal towards niches featuring similar environmental conditions. Nevertheless, significant instances of ecological niche shifts have also been observed in some lineages, making an important contribution to the overall diversification history of this clade.     

Tropical fruitflies (Diptera: Tephritidae) of the Krakatau Archipelago in 1990 and comments on faunistic changes since 1982

Three of the Krakatau islands, in Sunda Strait, some 40 km from both Java and Sumatra, are believed to have been totally devastated by the famous cataclysmic eruption of 1883. The fourth, Anak Krakatau, is an emergent volcanic island which rose from Krakatau's submerged 1883 caldera in 1930, suffered a self-devastating eruption in 1952/3 and several severely damaging ones since then. In 1990 the tephritid fauna was monitored on all the islands with Steiner traps. Nine species were found, five of which appeared to have been found by Yukawa in 1982 (Yukawa 1984) using similar methods and lures, when he noted a total of six species. As in 1982, the fauna in 1990 was characterized by the numerical dominance ofBactrocera albistrigata (de Meijere) although this appeared to be less marked than in 1982 andBactrocera papayae Drew & Hancock appeared to have increased in relative numbers. The distribution of three species over the islands of the archipelago had increased and four species not found in 1982 were present. Rakata, Krakatau's remnant and by far the largest and highest island, carried seven species (six in 1982), Sertung three (two in 1982), Panjang four (one in 1982) and Anak Krakatau four (one in 1982). Capture rates were lower than in 1982 but still higher than those obtained on the Javan mainland in 1982. There was a marked difference between the tephritid faunas of Anak Krakatau's two forelands, which were at different stages of biotic succession.     

Kinetics of Aggregate Formation in Social Insects

A model for the kinetics of aggregation in social insects which accounts for stochastic effects arising from individual variability and covers both the early and the mature stages of the process is developed. Different aggregation scenarios are studied, depending on the degree of cooperativity and the mean population density. It is shown that under certain conditions, the system evolves slowly to a single cluster incorporating all individuals, or to two coexisting clusters of similar sizes. Present address: Department of Zoology, University of Oxford, OX1 3PS Oxford, UK.     

Diversity of butterflies on British islands: ecological influences underlying the roles of area, isolation and the size of the faunal source

To distinguish between the influences of area and isolation on the butterfly faunas of British islands two approaches are adopted. First, species richness is related to island area, isolation and the size of the faunal source. Neither area nor isolation account for much variance in species richness, though area is more important than isolation. In contrast, species richness corresponds closely to the size of the faunal source on nearby islands and to that at proximate locations on adjacent mainlands. The second approach relates the incidence of species on islands to their ecological attributes. A very close relationship is found between species incidence on islands and those ecological variables that measure potential for migration and colonization and that resist extinction. The implications are that the majority of British islands in this survey are insufficiently isolated to prevent intermittent migrations of butterflies to them or so small as to generate frequent extinctions. Independent data indicate the capacity of many resident species to migrate distances in excess of the isolation of most of the islands. Some evidence also exists for the long-term survival of species on islands; important considerations in this respect are that most islands in the survey are large compared to habitat patches sustaining species on mainland Britain and that substantial portions of islands are retained in early seral stages or comprise long-lived stable habitats (e.g. peat mosses) that are particularly suitable for many British species.