First report of leaf spot caused by <Emphasis Type="Italic">Alternaria alternata</Emphasis> on <Emphasis Type="Italic">Drimia maritima</Emphasis>

Drimia maritima (squill) is a historically important medicinal plant. During the spring of 2016, small, yellow leaf spots, which became brown and finally necrotic, were observed on squill plants in Kohgiluyeh and Boyer-Ahmad Provinces in Iran. A fungus was consistently isolated from infected leaves and identified as Alternaria alternata based on morphological and phylogenetic analyses. Pathogenicity tests confirmed A. alternata to be the causal agent of the newly observed leaf spot disease. This is the first report of leaf spot on D. maritima caused by A. alternata in the world.     

我国动物疫病风险评估研究热点和趋势——基于CiteSpace的可视化分析

为探究我国动物疫病传播风险评估的研究热点及趋势,以2000—2019年“中国知网”（CNKI）数据库收录的348篇动物疫病风险评估相关文献为研究对象,利用CiteSpace软件对文献进行时空分析和内容分析。时空分析显示,这20年间动物疫病风险评估文献数量呈现从少到多再减少的动态过程,各大研究机构合作较少。内容分析显示,研究热点主要涉及“风险评估”“风险分析”和“动物疫病防控”等方面。提示研究机构应加大动物疫病风险评估研究力度,加强各大研究机构间的合作,推进动物疫病风险评估的研究、分析、监管,完善预警机制,进一步提升我国动物疫病防控水平。本研究可为深化动物疫病风险评估研究、实践和预警提供参考。     

高毒有机磷农药慢性危害评估方法研究

为探索高毒有机磷农药残留对人群慢性危害的评估方法,本文以江苏省甲胺磷、甲拌磷、对硫磷、甲基对硫磷以及氧乐果在蔬菜中残留的实测数据和文献中相关参数为基础资料,采用饮食暴露模型(DEEM)估算江苏省人群对蔬菜中这5种有机磷农药残留的暴露水平,分别采用参考剂量百分比、暴露边缘以及日允许摄入量百分比3种评估方法从不同角度对其慢性危害进行分析。危害分析结果表明:江苏省人群对蔬菜中这5种有机磷农药的暴露水平目前仍属于安全范围。3种评估方法同时对慢性危害进行评估,可以避免遗漏高风险农药,同时量化农药的慢性危害。     

爵床提取物对辣椒炭疽病菌的抑制作用及其苗期防效

爵床(J usticia procumbens L.)是一种传统的中药材.为探明爵床提取物对辣椒炭疽病菌的抑制作用,采用生长速率法和孢子萌发法分别测定了爵床提取物对辣椒炭疽病菌菌丝生长、孢子产生和孢子萌发的抑制作用,采用苗期盆栽试验观察爵床提取物对辣椒炭疽病的防治效果.结果表明,爵床甲醇提取物可抑制辣椒炭疽病菌菌丝生长、孢子产生和孢子萌发,其活性随着浓度的提高而增强,抑制中浓度分别为4.23、2.16和2.98 mg/mL.通过对爵床提取物处理后病菌孢子萌发形态显微观察,发现病菌孢子芽管长度受到明显抑制甚至不能萌发.当提取物浓度为16mg/mL时对苗期辣椒炭疽病的防效达73.08％.     

Consequences of a large-scale fragmentation experiment for Neotropical bats: disentangling the relative importance of local and landscape-scale effects

Context

Habitat loss, fragmentation and degradation are widespread drivers of biodiversity decline. Understanding how habitat quality interacts with landscape context, and how they jointly affect species in human-modified landscapes, is of great importance for informing conservation and management.

Objectives

We used a whole-ecosystem manipulation experiment in the Brazilian Amazon to investigate the relative roles of local and landscape attributes in affecting bat assemblages at an interior-edge-matrix disturbance gradient.

Methods

We surveyed bats in 39 sites, comprising continuous forest (CF), fragments, forest edges and intervening secondary regrowth. For each site, we assessed vegetation structure (local-scale variable) and, for five focal scales, quantified habitat amount and four landscape configuration metrics.

Results

Smaller fragments, edges and regrowth sites had fewer species and higher levels of dominance than CF. Regardless of the landscape scale analysed, species richness and evenness were mostly related to the amount of forest cover. Vegetation structure and configurational metrics were important predictors of abundance, whereby the magnitude and direction of response to configurational metrics were scale-dependent. Responses were ensemble-specific with local-scale vegetation structure being more important for frugivorous than for gleaning animalivorous bats.

Conclusions

Our study indicates that scale-sensitive measures of landscape structure are needed for a more comprehensive understanding of the effects of fragmentation on tropical biota. Although forest fragments and regrowth habitats can be of conservation significance for tropical bats our results further emphasize that primary forest is of irreplaceable value, underlining that their conservation can only be achieved by the preservation of large expanses of pristine habitat.

     

Comparison of larval thermal maxima between <Emphasis Type="Italic">Fundulus heteroclitus</Emphasis> and <Emphasis Type="Italic">F. grandis</Emphasis>

Fundulus heteroclitus and F. grandis are resident salt marsh fishes that overlap in distribution over a narrow range in northeastern Florida. The objective of the present study was to examine whether the limits of the species’ ranges could be explained by differences in thermal tolerance. Two populations of each species were collected and then spawned in the laboratory, and 9-day-old larvae were used for critical thermal maxima trials. Mean LOE temperatures of larvae ranged from 43.04 to 43.65°C and showed little difference between species. Therefore, differences in high temperatures experienced cannot account for the differences of the distributions of the two species. Condition-specific competition may play a greater role in determining the observed range of the two species.     

台湾青枣不同品种花粉萌发和生活力测定

以5个台湾青枣品种盛花期花粉为试材，应用正交试验测定不同品种花粉萌发率及适宜的萌发条件，并用4种不同方法测定花粉生活力。结果表明：（1）不同品种的花粉萌发率存在显著差异，其中大世界的花粉萌发率最高。（2）硼酸浓度、培养温度等因素对花粉萌发率有极显著影响。最适培养基为含琼脂1％、蔗糖15％、硼酸0．02％的组合，适宜温度为30—32℃。（3）花粉生活力的测定中，离体萌发法是最佳选择，I—KI染色法、醋酸洋红染色法和TTC染色法不适宜用作台湾青枣花粉生活力的测定。     

In vitro inhibitory effect of trichostatin A on canine grade 3 mast cell tumor

Mast cell tumor (MCT) is one of the most prevalent neoplasms that affect skin and soft tissue in dogs. Because mast cell tumors present a great variety of clinical appearance and behavior, their treatment becomes a challenge. Trichostatin A (TSA), an antifungal antibiotic, has shown inhibitory effects on the proliferation and induction of apoptosis in various types of cancer cells. In order to evaluate the potential of trichostatin A as a therapeutic drug, cells of grade 3 MCT were cultured and treated with concentrations of 1 nM to 400 nM of TSA. MTT assay and trypan blue exclusion assays were performed to estimate cell growth and cell viability, and cell cycle analysis was evaluated. TSA treatment showed a reduction in numbers of viable cells and an increase of cell death by apoptosis. The cell cycle analysis showed an increase of hypodiploid cells and a reduction of G0/G1 and G2/M –phases. According to these results, trichostatin A may be an interesting potential chemotherapeutic agent for the treatment of canine MCT.     

七个鸡种蛋品质比较分析

鸡蛋品质是鸡蛋生产者和消费者都非常关注的性状,为分析蛋品质在鸡种内及鸡种间的差异,本试验测定了5个地方鸡种和2个国外蛋鸡品种各30个蛋共12项常规蛋品质指标。分析结果表明:遗传背景对蛋品质影响较大,2个国外鸡种的蛋重、哈氏单位等指标高于地方鸡种,而地方鸡种在蛋形指数、蛋壳质量、蛋黄颜色以及蛋黄比率上占优,国内蛋用鸡种改良可以选择蛋黄性状为重点选育方向。7个鸡种中,海兰白蛋鸡的蛋壳厚度、蛋壳强度、蛋黄重是最大的,但海兰褐蛋鸡却与之完全相反,两者之间差异显著(P<0.05)。从品种内差异角度来看,商业化鸡种蛋品质变异系数小,国内鸡种整齐度有待进一步提高。