Effect of Sclerotial Damage of Sclerotinia sclerotiorum on the Mycoparasitic Activity of Trichoderma hamatum

Damaged sclerotia of Sclerotinia sclerotiorum buried in soil infested with Trichoderma hamatum isolate TMCS - 3 were degraded rapidly when the medulla of sclerotia was com pletely exposed by the feeding activity of larvae of the fungus gnat Bradysia coprophila. These heavily damaged sclerotia also enhanced , in vitro, the growth of TMCS - 3 . Growth of TMCS - 3 in liquid culture was studied using different carbon sources as substrates , including sclerotia of S. sclerotiorum. Significantly more biomass of TMCS - 3 was recovered using sclerotia as a substrate compared to other carbon sources tested . Exudates from sclerotia whose melanized rinds had been completely removed by feeding larvae accelerated the germination of conidia of TMCS - 3 . Concentrations of amino acids , carbohydrates and proteins in the sclerotial exudates were not increased as damage to sclerotia was increased . Exudation of electrolytes was higher in undamaged than damaged sclerotia . Glucanase activity of TMCS - 3 was slightly increased when the fungus was exposed to damaged sclerotia . However , chitinase activity was not increased by damaging the sclerotia . Larval damage altered the sclerotia not only physically but also chemically , thereby enhancing the activity of the fungus T. hamatum.     

为害竹荪和木耳的眼蕈蚊二新种（双翅目：眼蕈蚊科）

双翅目眼蕈蚊科为菌蕈的重要害虫,本文描记福建省竹荪和木耳上的二新种,并与近似种进行了比较,附新种的特征图以便于识别。     

韭菜迟眼蕈蚊对新烟碱类杀虫剂的抗药性及抗性机制初探

【目的】为明确韭菜迟眼蕈蚊Bradysia odoriphaga对新烟碱类杀虫剂的抗性水平及其抗性机制。【方法】通过测定不同地区韭菜迟眼蕈蚊对3种新烟碱类杀虫剂吡虫啉、噻虫嗪和噻虫胺的敏感度,及通过增效剂实验和酶活性测定,初步探索抗性产生机制,为韭菜迟眼蕈蚊抗性治理提供依据。【结果与结论】4个不同的韭菜迟眼蕈蚊田间种群对3种新烟碱类杀虫剂均产生了不同水平的抗性。其中,唐山种群对3种新烟碱杀虫剂均产生了较高的抗性。研究发现,唐山种群的7-乙氧基香豆素-O-脱乙基酶(ECOD)比活力为(3.89±0.31)pmol/(mg·pro·min),显著高于敏感品系。增效剂PBO对唐山种群的吡虫啉毒力的增效比为2.64,高于对敏感品系的增效比1.08。因此,P450s酶活性的升高与韭菜迟眼蕈蚊对吡虫啉的抗性有关。     

韭菜迟眼蕈蚊规模化饲养技术

【目的】韭菜迟眼蕈蚊Bradysia odoriphaga Yang et Zhang是为害韭菜等蔬菜的重要害虫,规模化饲养提供大量虫源是其他研究工作得以开展的基础。本研究旨在解决目前韭菜迟眼蕈蚊饲养规模小、材料和劳动力成本高等问题。【方法】本实验室利用土豆、花生、大豆为食物进行了规模化饲养韭菜迟眼蕈蚊的研究,测定了取食上述饲料的韭菜迟眼蕈蚊的成活率、繁殖力、羽化节律和性比。【结果】取食土豆、花生、大豆等食物的韭菜迟眼蕈蚊的成活率和繁殖力与取食人工饲料和韭菜的无显著差异,卵到成虫的发育历期为20~23 d,雌雄性比为0.8︰1~1.2︰1。在规模化饲养过程中,土豆、花生、大豆等饲料有发霉长菌现象,经分子鉴定,主要种类为雅致放射毛霉、巴克斯毛霉、黄曲霉和赭曲霉,均为腐生菌,不影响韭菜迟眼蕈蚊的存活和繁殖。【结论】该技术省工省时,成本低,特别适合实验室种群的维持和大量试虫的饲养。     

龄期、饲养条件及生测方法对韭菜迟眼蕈蚊对药剂敏感性的影响

为建立针对韭蛆的简便、可靠的生测方法，采用胃毒触杀联合毒力法、人工饲料混药法和浸虫法分别测定毒死蜱、噻虫胺对韭蛆不同龄期幼虫的毒力，以明确龄期、温度和饲料等饲养条件及生测方法对韭菜迟眼蕈蚊对药剂敏感性测定结果的影响。三种方法测得2龄幼虫对毒死蜱的敏感性分别为4龄幼虫的11.9倍、7.4倍、3.3倍；4种饲料饲养的试虫，毒死蜱对取食韭菜、人工饲料、大葱的LC50分别为圆葱的1.84倍、1.47倍、2.31倍；在15~30℃范围内，随着试虫的饲养温度的升高，毒死蜱对韭蛆4龄幼虫的LC50不断增大；三种方法测得毒死蜱对4龄幼虫的LC50分别为67.199 mg/L、71.123 mg/L、88.120 mg/L，噻虫胺对4龄幼虫的LC50依次为3.584 mg/L、2.255 mg/L、4.329mg/L，并且胃毒触杀联合毒力法和人工饲料混药法的毒力曲线拟合度要好于浸虫法。试验表明：试虫龄期、饲养温度、饲养饲料等因素对韭菜迟眼蕈蚊对药剂敏感性存在明显影响，采用胃毒触杀联合毒力法和人工饲料混药法测定的结果比浸虫法准确可靠。     

Effects of short-term heat stress on the growth and development of Bradysia cellarum and Bradysia impatiens

Bradysia cellarum Frey and Bradysia impatiens Johansen are major pests of vegetable crops, as well as edible mushrooms and ornamental plants, and damage to hosts resulting in economic losses. Temperatures above the optimum levels for these pests have been predicted to regulate their population growth during summer. The aim of the present study was to examine the effects of both heat stress and exposure time on the growth and development of eggs, larvae and pupae for two Bradysia species. The egg stage, egg hatching rate, 4th instar larval stage, pupation rate, pupal stage and adult emergence rate were observed after exposing at high temperatures of 34°C, 37°C and 40°C for 1, 2, 4 and 6 hr. The results showed that 34°C, 37°C and 40°C for 1-, 2-, 4- and 6-hr exposure treatments prolonged the developmental stage of egg, 4th instar larva and pupa, while decreasing the egg hatching rate, pupation rate and adult emergence rate. This suggests that increasing temperature or prolonging exposure time to the heat stress could significantly affect insect survival, growth and development. Our study could provide an ecological basis for pests’ management strategy by using short-term heat stress.     

韭菜迟眼蕈蚊的性别分化及其生态与进化意义

性别分化是遗传学、进化生物学和生殖行为生态学研究的重要领域之一,对于研究生物的遗传与进化关系、分析生物种群数量动态具有重要意义。对韭菜迟眼蕈蚊BradysiaodoriphagaYangetZhang的性别分化研究结果表明,韭菜迟眼蕈蚊的生殖对策主要以产单性别方式为主,其次是产优势性别方式,2种方式占92%,且产雌产雄的比例基本呈对称现象。用雌雄试虫都来自单性别的种群,连续繁殖3代,其性别分化如同上述,每一代种群的性比基本保持在1∶1。用双性别后代雌虫所产的雌雄虫进行近亲繁殖,连续繁殖3代,结果表明双性别后代的比例明显增大。鉴于以上实验结果,对韭菜迟眼蕈蚊生殖对策的生态与进化意义进行了分析。     

Molecular characterization of the 5S ribosomal gene of the <Emphasis Type="Italic">Bradysia hygida</Emphasis>(Diptera:Sciaridae)

The rRNA genes are amongst the most extensively studied eukaryotic genes. They contain both highly conserved and rapidly evolving regions. The aim of this work was to clone and to sequence the Bradysia hygida 5S rDNA gene. A positive clone was sequenced and its 346 bp sequence was analyzed against the GenBank database. Sequence analysis revealed that the B. hygida 5S (Bh5S) rDNA gene is 120 bp long and is 87% identical to the aphid Acyrthosiphon magnoliae 5S rDNA gene. The Bh5S rDNA gene presents two unusual features: a GG pair at the 5' end of the gene sequence and the localization of the polyT signal immediately after the 3' end of the gene. In situ5S hybridization experiments revealed that the Bh5S rDNA gene is localized in the autosomal A chromosome     

中国重要农业害虫韭菜迟眼蕈蚊多态性EST-SSR标记的开发

【背景】韭菜迟眼蕈蚊是我国重要的农业害虫,然而它的遗传资源有限。本研究旨在开发韭菜迟眼蕈蚊EST-SSR标记,为研究不同地区的韭菜迟眼蕈蚊种群结构和遗传多样性奠定基础。【方法】从韭菜迟眼蕈蚊的表达序列标签(EST序列)中设计16对简单重复序列(SSR)引物,进一步筛选出9对具有多态性的SSR引物。【结果】从42095条unigene中确定了3383个SSR位点。利用查找到的SSR位点共设计出16对引物,进一步检测筛选发现9对引物具有多态性,引物的每个位点平均有3.33个等位基因。利用9对引物对30头韭菜迟眼蕈蚊进行检测,共获得30个等位基因,观测杂合度和期望杂合度的范围分别为0.0000~0.6875和0.0370~0.6877;其中,9个位点中有5个位点显著偏离Hardy-Weinberg平衡。【结论与意义】本研究成功从迟眼蕈蚊EST序列中筛选出9个具有多态性的微卫星位点,这为进一步分析该害虫种群的遗传结构和遗传多样性奠定了基础。     

五种细菌侵染后韭菜迟眼蕈蚊体内防御反应的研究

为了解韭蛆体内5种细菌对韭菜迟眼蕈蚊Bradysia odoriphaga的影响,本研究将解淀粉芽孢杆菌Bacillus amyloliquefaciens、居泉沙雷氏菌Serratia fonticola、恶臭假单胞杆菌Pseudomonas putida、枯草芽胞杆菌Bacillus subtilis和节杆菌Arthrobacter nitroguajacolicus 5种细菌通过浸泡和针刺两种方式对韭蛆进行侵染,观察韭蛆存活率、蛋白含量以及3种抗氧化酶活性的变化规律。结果显示,与浸泡接种细菌相比,针刺接种细菌后,韭蛆整体的存活率和SOD酶活性下降,而蛋白含量、POD活性和CAT活性上升。其中,居泉沙雷氏菌在针刺侵染后对韭蛆表现出致病性。因此,机械损伤对于细菌的侵染具有重要的作用,韭蛆则可通过改变抗氧化酶的活性来防御细菌的侵染。本研究为探索韭蛆与体内共生微生物之间的关系提供重要的基础,为韭蛆的共生防治提供指导。