粉红粘帚霉化学成分的研究

粉红粘帚霉对名贵药用植物金线莲有明显的促进作用,为了从物质角度探讨其可能的促生机理,对该菌的化学成分进行了初步研究,从该菌的菌丝体中共分离到5个化合物,通过结构解析,确定它们是：化合物1,6,22－二烯－3－羟基－5,8－过氧麦角甾,2,麦角甾醇;3,阿拉伯糖醇;4,甘露醇,另外一个化俣物的结构正在鉴定中。     

Habitat-dependent song divergence in the little greenbul: an analysis of environmental selection pressures on acoustic signals

Abstract.— Bird song is a sexual trait important in mate choice and known to be shaped by environmental selection. Here we investigate the ecological factors shaping song variation across a rainforest gradient in central Africa. We show that the little greenbul ( Andropadus virens ), previously shown to vary morphologically across the gradient in fitness-related characters, also varies with respect to song characteristics. Acoustic features, including minimum and maximum frequency, and delivery rate of song notes showed significant differences between habitats. In contrast, we found dialectal variation independent of habitat in population-typical songtype sequences. This pattern is consistent with ongoing gene flow across habitats and in line with the view that song variation in the order in which songtypes are produced is not dependent on habitat characteristics in the same way physical song characteristics are. Sound transmission characteristics of the two habitats did not vary significantly, but analyses of ambient noise spectra revealed dramatic and consistent habitat-dependent differences. Matching between low ambient noise levels for low frequencies in the rainforest and lower minimal frequencies in greenbul songs in this habitat suggests that part of the song divergence may be driven by habitat-dependent ambient noise patterns. These results suggest that habitat-dependent selection may act simultaneously on traits of ecological importance and those important in prezygotic isolation, leading to an association between morphological and acoustic divergence. Such an association may promote assortative mating and may be a mechanism driving reproductive divergence across ecological gradients.     

A Redescription of Climacostomum virens (Ehrenberg) Stein and Proposal of a New Heterotrich Ciliate Family, Climacostomidae fam. n.

SYNOPSIS. Structure of the vegetative and asexually dividing forms of the large ciliate Climacostomum virens is redescribed with emphasis on stomatogenesis. These findings are discussed in relation to the taxonomic and possible evolutionary position of Climacostomum among heterotrichous ciliates. Comparative considerations of the buccal and somatic structures as well as of the stomatogenic patterns in this and other closely related ciliate genera indicate the need for placing Climacostomum and Fabrea in a new family, CLIMACOSTOMIDAE . The morphologic evidence suggests that Climacostomum may represent a line linking Fabrea and Stentor.     

Termite pathogens: Effects of ingested Metarhizium,beauveria, and Gliocladium conidia on worker termites (Reticulitermes sp.)

Separate groups of subterranean termites (Reticulitermes sp.) were exposed to whole cultures of Beauveria bassiana, Gliocladium virens, or Metarhizium anisopliae. Individuals were removed after varying time intervals and hindgut contents were plated onto potato dextrose agar. Viable spores first appeared in the hindguts within 8 hr of exposure. Fungi reisolated from the hindguts of diseased termites were pathogenic of healthy termites. Histological examination showed that invasion of the hemocoel by M. anisopliae occurred exclusively through direct invasion of the integument ca. 24 hr after death. B. bassiana invaded, primarily through the alimentary tract, ca. 12 hr prior to termite death.     

Evidence of suboscine song plasticity in response to traffic noise fluctuations and temporary road closures

This study investigates how noise reduction (road closure) mitigates the effect of traffic noise on the acoustic communication of the Eastern wood pewee (Contopus virens) (EAWP), a suboscine passerine. Songs were passively recorded at sites where the traffic pattern of the nearest road was either relatively constant or reduced on a weekly basis during a 36 h road closure. Five song attributes, low frequency traffic noise amplitude (LAeq) measured within 20 s of each song, and full-spectrum background noise levels (LAeq) characteristic of each territory were measured and analysed in order to better understand how EAWP respond to variation in traffic noise levels. EAWP adjusted its spectral song attributes by increasing song tonality to improve transmission in immediate response to fluctuations in traffic noise. The results suggest that song adjustments are responses to traffic noise levels at the time of their song, instead of the average background noise level measured per territory. This study provides a better understanding of how suboscine communication is affected by traffic noise, as well as the potential mitigating effect of noise reduction for animal acoustic communication.     

Biological treatments to control bacterial canker of greenhouse tomatoes

Experiments were conducted to determine the effects of treatments on Clavibacter michiganensis subsp. michiganensis in vitro and on young seedlingsinoculated with the pathogen under greenhouseconditions. Lysozyme was bactericidal at 10 g/l concentration in vitro. Tomato plantstreated with lysozyme at 10 g/l and 100 g/lshowed significantly higher plant heightcompared with the inoculated control plants,and plants in these treatments were as tall asthose observed in untreated uninoculatedcontrol plants. Treatments with B. subtilis (Quadra 136) and Trichoderma harzianum (RootShield®), lysozyme,vermicompostea, Rhodosporidium diobovatum(S33), B. subtilis (Quadra 137) appliedas a spray at 0.3 g/l, 0.6 g/l, 10 g/l,concentrated, 1 × 10⁹ CFU/ml, and 0.5 g/l,respectively, have the ability to prevent theincidence of bacterial canker of tomato plantscaused by C. michiganensis subsp.michiganensis under greenhouse conditions.     

The structure and function of a muscle articulation‐type jaw joint of a polychaete worm

The arrangement of the musculature and the fibers of the extracellular matrix (ECM) in the flexible jaw joint of the sandworm Alitta virens (Annelida, Polychaeta) was studied using dissection and histology. The jaws are capable of a wide range of motions principally related to defense and feeding. The left and right jaws are embedded in and moved by a compact pharyngeal bulb of muscle and ECM that also forms the mouth and esophagus. Eight pharyngeal bulbs were removed and dissected to document gross anatomical features or preserved and embedded in plastic for sectioning in multiple planes. The sections were stained with toluidine blue and basic fuchsin to differentiate muscle and ECM. The sections were then digitized and used to develop a three‐dimensional computer illustration. We hypothesize that the muscle and fibers in the ECM are arranged as a muscular hydrostat to support the movement of the jaws. Four specimens were recorded using a digital video camera and a tank with an angled mirror to record lateral and ventral views of jaw movements during locomotion and biting associated with burrow guarding and feeding. Frame by frame kinematic analysis of this video showed that the jaws move symmetrically in a roughly horizontal plane. Although the angle between the jaws increases and then decreases after maximum gape has been reached, the jaws also translate relative to each other such that the axis of rotation is not fixed. Together, these functional morphological and behavioral data identify the jaw mechanism as a flexible joint known as a muscle articulation. As muscle articulations have been previously described only in the beaks of cephalopods and flatworms, this study implies that this type of joint is more common and important than previously recognized. J. Morphol. 276:403–414, 2015. © 2014 Wiley Periodicals, Inc.     

Does seasonal reproduction occur at the optimal time for fertilization in the polychaetes Arenicola marina L. and Nereis virens Sars?

Summary

Many marine invertebrates exhibit highly seasonal and synchronised reproduction, with offspring production often being confined to just two or three days each year. Several models have been proposed to explain the fitness benefits of this reproductive pattern, many of which assume enhanced offspring survival due to temperature constraints placed on fertilization and development at other times of the year. In this investigation the temperature limits and optimum for fertilization were determined for two polychaete species, Arenicola marina and Nereis virens. These two polychaete species are exposed to the same environmental conditions throughout the year, yet breed at very different times. Other seasonal impacts on fertilization, i.e., reduced salinity due to rainfall and the effect of sub-zero temperatures on sperm of A. marina, were also investigated. In both A. marina and N. virens fertilization success was significantly influenced by temperature, with the maximum success recorded at 15–18°C. The ambient seawater temperature at the time of natural spawning for both worms is around 10°C, which means that both species are spawning right at the lower limit for maximum fertilization. Salinity and exposure of A. marina sperm to sub-zero temperatures were also found to influence fertilization success, but only at levels that would not be experienced by these polychaetes under natural conditions at the time of spawning. These results suggest there must be additional selective pressures acting on the fitness of these two polychaetes causing A. marina to breed later than, and N. virens to breed earlier than, the optimum time for fertilization. A. marina apparently waits as late as possible to maximise adult fecundity and survival. N. virens breeds as soon as it can achieve high fertilization to maximise larval and juvenile competitiveness.