根癌农杆菌介导的木霉插入转化及其应用

根癌农杆菌介导的遗传转化法(ATMT)已广泛地应用于真菌的转化研究,该方法具有操作简单、转化效率高和转化子遗传稳定等特点。木霉作为土传植物病原菌的重要生防真菌,对其生防分子作用机制方面的研究也越来越受到关注,目前所面临的问题是如何基因突变和基因替换。ATMT法为木霉(Trichodermaspp.)的分子生物学研究提供了一个强有力的工具,在木霉的插入突变、遗传转化以及基因标记和克隆方面起着重要的作用。本文综述了根癌农杆菌介导木霉遗传转化的原理、特点、转化方法和应用,并且对有关发展趋势进行了展望。     

酸法提取红雪茶渣水不溶性膳食纤维的工艺优化

利用红雪茶渣作为提取工艺的原料,运用简便的酸液提取法制备红雪茶渣水不溶性膳食纤维,为红雪茶渣水不溶性膳食纤维副产物的综合开发利用开辟新途径,为生产水不溶性膳食纤维提供新料源思路.在酸液浓度、料液比、处理温度、处理时间4个单因素试验的基础上设计四因素三水平的正交试验,研究红雪茶渣水不溶性膳食纤维的最佳工艺条件.结果表明,影响红雪茶渣水不溶性膳食纤维产率的因素由大到小次序为:料液比处理温度酸液浓度处理时间.通过正交试验结果获得的最佳工艺条件为:酸液浓度0.10 mol/L,酸处理时间3.0 h,酸处理料液比1∶50 g/m L,酸处理温度50℃.该提取条件下,红雪茶渣水不溶性膳食纤维的得率为(34.61±0.19)%.     

菟丝子属植物的生物学特性及其对薇甘菊的防除

菟丝子属CuscutaL 为旋花科的寄生草本 ,该属的一些种的种子是中药药材。种子有休眠特性 ,在土中寿命很长 ,温度、湿度和种子在土壤中的深度影响种子的萌发出苗。田野菟丝子C .campestris千粒质量为0 5 6 8g ,种子所贮藏的养分只能维持幼苗短期的自养生长。种子繁殖和断枝繁殖是菟丝子属植物繁殖的重要途径。在暖温带地区 ,菟丝子属植物在冬天下雪后枯死 ,靠成熟种子越冬 ,翌年春天萌发 ,并侵染寄主。广东沿海的田野菟丝子的枝条可安全越冬。菟丝子属植物的寄主广泛。田野菟丝子在广东有分布 ,但未成灾。田野菟丝子在外来恶性杂草薇甘菊MikaniamicranthaH B K 上易寄生 ,导致薇甘菊死亡 ,这一特性有可能应用于大面积控制薇甘菊危害。实验表明 ,用田野菟丝子断枝直接寄侵野外生长的薇甘菊不易成功 ,而用种植于营养袋的大豆作为田野菟丝子过渡寄主 ,然后用已在大豆上寄生的田野菟丝子作为寄侵源来控制薇甘菊的生长是可行的。     

几种不同楸树花粉萌发率的测定及花粉超低温保存方法

对5种不同楸树(楸树、滇楸、梓树、灰楸和黄金树)花粉萌发率的研究表明:花粉在恒温25℃培养6 h时萌发率较好,培养基为:10%蔗糖 0.01%硼酸 1%琼脂。在室温水培条件下,花粉在3 d内都保持较好的萌发率,第4天至第7天萌发率快速下降。花粉在液氮和-70℃条件下贮藏生活力较好,随贮藏时间延长生活力下降幅度也较小;常温贮藏时花粉萌发率最低,且生活力丧失快;而0℃和-20℃贮藏花粉生活力居中。超低温保存后花粉的解冻方式对花粉的萌发率影响较大,楸树各树种均以温水浴(35~38℃)下解冻5 min效果最好。     

2株重寄生木霉菌丝生长的生物学特性

对2株茶藨生柱锈菌(Cronartium ribicola J.C.Fischer)重寄生木霉(Trichoderma spp.)TR1、TR2菌株菌丝生长及产孢条件进行单因素筛选及正交实验。结果表明：TR1菌丝生长速度快,且极易产生分生孢子;TR2菌丝生长速度相对较慢,产孢受一定条件限制。光照和VB2能明显刺激TR2分生孢子的产生。2株菌在以大麦粉、黄豆粉、KH2PO4、复合VB为培养基,5%接种量、120r／min、pH为 6的条件下菌丝生长最佳。TR1和TR2菌丝生长的最适温度范围及水势分别为25～30℃、-232MPa和20～25℃、-454MPa.     

黄河三角洲外来人侵物种米草对海涂浮游动物的影响

2005年5、8、10月份对黄河三角洲米草分布区的无棣岔尖、东营市五号桩、小清河口的浮游动物作了调查监测,与1980年同期调查资料相比较,结果表明：米草分布已导致调查区浮游动物群落组成与结构的变化,浮游动物生物量减少,浮游动物多样性指数降低。     

实验犬布鲁杆菌诊断试剂的制备和应用

目的　制备犬布鲁杆菌试管凝集菌液和抗血清。方法　苯酚生理盐水冲洗在肝浸液中培养的布鲁杆菌菌苔 ,参照标准比浊管制成所需浓度菌液。采用人工接种比格犬和家兔的方法 ,试管凝集试验测定所得抗血清效价。结果　家兔抗S型血清效价达 1∶32 0 0以上 ,R型抗血清效价达 1∶2 5 6 0以上。比格犬抗血清效价较低 ,最高为1∶6 4 0。结论　S型布鲁杆菌通过静脉免疫即可获得效价较高的抗血清 ,而犬R型布鲁杆菌需采用加佐剂肌肉注射的方法 ,血清效价才能达到较高水平     

Two new species of the commensal shrimp genus Periclimenaeus Borradaile, 1915, (Decapoda,Palaemonidae) from the Maldive Islands

Two new species of the commensal shrimp genus Periclimenaeus Borradaile, found in the waters of the Maldive Islands, Indian Ocean, are described and illustrated. P. tchesunovi sp. nov. is related to P. rastrifer Bruce. The former may be distinguished by its deeper rostrum, with dentition 6/1, the presence of supraorbital tubercles, and broad, spatulate fingers on the first pereiopods. P. zarenkovi sp. nov. closely resembles P. diplosomatis Bruce in the presence of minute denticulations on the dactylar cutting edge of the major second pereiopod, but differs from it by a deeper rostrum with 5 dorsal teeth, more robust chelae of the second pereiopods, and small dorsal telson spines.     

Natural occurrence of entomopathogenic nematode species (Rhabditida: Steinernematidae and Heterorhabditidae) in cotton fields of Tamil Nadu,India

A total of 200 soil samples collected from the cotton fields of 10 different districts of the state of Tamil Nadu in India were evaluated for the presence of entomopathogenic nematodes (EPN) belonging to Steinernematidae and Heterorhabditidae during 2008–2009. This survey detected the occurrence of EPN in arable lands through the use of a standard insect baiting bioassay technique. EPN were recovered from all 10 cotton growing districts with 27 positive sites (13.5%) ranging from irrigated to rain-fed cotton fields of varied soil types (sandy to clayey), soil pH (4.9–8.4), electrical conductivity (0.11–1.25 dS/m) and organic matter content (0.21–3.8%). Both morphological and molecular tools were used to identify the isolates. Among 27 positive samples, 20 samples yielded steinernematids (74%) and seven samples yielded heterorhabditids (26%). The Heterorhabditis isolates were identified as Heterorhabditis bacteriophora. The Steinernema included Steinernema carpocapsae, Steinernema siamkayai and Steinernema monticolum. Steinernema carpocapsae was the predominant species. The cropping patterns comprising cotton–vegetables had higher EPN prevalence (26%) than cotton–pulses (22%), cotton–banana (3.3%) and cotton–millets (2.8%). Steinernema carpocapsae was recovered from cotton–pulses, cotton–millets and cotton–vegetables cropping patterns, whereas H. bacteriophora was isolated from cotton–pulses, cotton–vegetables and cotton–banana cropping patterns. This study demonstrated that EPN are prevalent in the cotton fields of Tamil Nadu, India and could potentially be incorporated into biological control or integrated pest management programmes.