云南金荞麦叶斑病病原菌的鉴定及其生物学特性

从云南省嵩明县试验基地采集金荞麦叶斑病病叶,采用组织分离法分离培养病原菌,根据柯赫氏法则测定病原菌的致病性,观察病原菌形态学特征,并与ITS、TUB2系统发育分析相结合鉴定病原菌,测定病原菌的生物学特性。结果表明：云南金荞麦叶斑病病原菌代表菌株GY3的孢子形态与拟盘多毛孢属(Pestalotiopsis)真菌相似,菌株GY3的rDNA–ITS及TUB2联合序列与小孢拟盘多毛孢(P. microspora)2个菌株(ZK1–1、ZK5–5)的序列聚在同一分支,鉴定认为金荞麦叶斑病的病原菌为小孢拟盘多毛孢(P. microspora);病原菌生物学特性测定结果表明,GY3菌丝生长最适培养基为PDA,以PDA培养基培养GY3,菌丝生长最适pH为7,最适温度为25 ℃,菌丝的致死温度为50 ℃(水浴10 min),连续光照最有利于菌丝生长,菌丝生长的最适的碳源和氮源分别为葡萄糖和蛋白胨。     

广义盘多毛孢属（Pestalotia deNot．S．1．）分类历史与最新进展

在综合大量文献的基础上，阐述了广义盘多毛孢属的分类历史，评述了以Ｇｕｂａ及Ｓｔｅｙａｅｒｔ为代表的两大分类体系。认为Ｇｕｂａ建立在广义属概念上的分类体系缺乏充分的科学依据。Ｓｔｅｙａｅｒｔ虽然对旧的分类做了具有进步意义的改动，但不尽完善之处依然存在。通过综合有性──无性二态联系，分生孢子壁与隔膜用微结构，分生孢子形态学等各方面的证据，支持将（ＰｅｓｔａｌｏｔｉａｄｅＮｏｔ．ｓ．１．）分裂为３个属的观点，即限制Ｐｅｓｔａｌｏｔｉａ为仅包括模式种的单种属，而把原归该属的其他种分归于Ｐｅｓｔａｌｏｔｉｏｐｓｉｓ与Ｔｒｕｎｃａｔｅｌｌａ。此外，对Ｍｏｎｏｃｈａｅｔｉａ与Ｓｅｉｒｉｄｉｕｍ的分类问题也作了讨论。     

云南葡萄病害研究初报

 本文报道云南22种葡萄真菌性病害,国内未报道的病害有9种,其中5种有描述和附图,即葡萄小褐斑病Anaphysmene sp,叶斑病Discosia sp,黑星病Fusicladium viticis,枝枯病Massamia phomeioides,大叶斑病Pestalotiopsis sp,后3种进行单孢分离接种;另4种为省内未报道的病害,即葡萄灰霉病Botrytis cinerea,黑点病Septoria sp,黑斑病Alternaria viticola,叶枯病Monochaetia uniseta,亦进行描述并附图。     

相对湿度对茶橙瘿螨种群的影响

研究了不同相对湿度下茶橙瘿螨的种群动态，表明相对湿度对茶橙瘿螨种群增长有明显的影响，相对湿度太低（RH＜50％）或太高（RH＞（90％）都不利于茶橙瘿螨种群的增长。在适宜温度下，最有利于茶橙瘿螨种群增长的湿度为75％＜RH＜90％。     

几种杀菌剂对茶轮斑病菌的室内毒力及田间药效

为了筛选防治茶轮斑病的化学药剂,采用菌落直径法测定了茶轮斑病菌对7种杀菌剂的敏感性,并对茶轮斑病菌高度敏感药剂进行田间药效试验。结果表明：轮斑病菌对阿米西达、世高、丙环唑、百菌清和苯菌灵高度敏感,其抑制中浓度（EC50）在0．0947～3．0630μg/mL;甲基托布津和多菌灵的 EC50分别为6．9649μg/mL 和7．0405μg/mL,表现为中度敏感（EC50＝5～20μg/mL）;田间药效以25％阿米西达SC 150 g/hm2的防效最高,达86．96％;其次为10％世高 WG 125 g/hm2、25％丙环唑 EC 112．5 g/hm2和75％百菌清WP 125 g/hm2,防效分别为81．16％、74．79％和72．38％;50％苯菌灵WP 325 g/hm2防效最低,为62．21％。     

Characteristics of Pestalotiopsis Associated with Hardy Ornamental Plants in the UK

Pestalotiopsis isolates obtained from the foliage, stem-base and roots of hardy ornamentals grown on commercial nurseries in the UK were identified and characterised according to pathogenicity and colony morphology. All 18 isolates were identified as Pestalotiopsis sydowiana on the basis of conidia morphology, and confirmation of identification was made by experts at CABI Bioscience. Isolates were pathogenic on the host from which originally isolated. Typical symptoms included foliar browning of foliage and stems, and the presence of black or greenish-black acervuli on diseased tissue. Isolates were not host specific and infected other species of hardy ornamentals. Three colony types on potato dextrose agar were distinguished according to colour and production of acervuli by individual isolates.Three selected isolates of P. sydowiana were characterised by examining the effects of growth media, temperature, pH, and water potential on hyphal extension. Isolates grew well on commonly used growth media, including PDA, Sabouraud dextrose agar (SDA), V8 juice agar (V8), malt extract agar (MEA) and Czapek Dox agar (CDA). The optimum temperature for growth on PDA was in the range 20–25°C, with little or no growth occurring below 5°C or above 30°C. Hyphal extension occurred over a pH range between 2.6–8.6, with optimum values occurring at pH 5.5. In general, decreases in osmotic and matric potential caused a reduction in growth. Hyphal extension on media adjusted osmotically as NaCl ceased between –9.9 and –10.5MPa. Isolates were more tolerant of osmotic than matric potential, with no growth occurring at –6.5MPa on media adjusted with polyethylene glycol.     

茶扁叶蝉 Chanohirata theae (Matsumura)的生物学特性

茶扁叶蝉Chanohirata theae(Matsumura)近年来在贵州部分茶园中偶有发生甚或暴发成灾,为了解这一害虫的生物学特性,通过室内饲养和野外调查对其形态特征、生活史、发育历期、生活习性等进行了研究。结果显示:茶扁叶蝉在贵州一年发生2代,第一代发生于4月上旬至9月下旬,第二代发生于7月中旬至翌年5月中旬;若虫共5龄,以5龄若虫在茶树中下部叶片上越冬;发育历期受温度影响明显,温度越高发育速率越快,第一代卵期(23.42d)明显长于第二代(15.73d),相反,第一代若虫历期(56.33d)明显短于第二代(218.28d);成、若虫均喜静伏于叶片正面取食,交配多于白天进行,雌成虫一般由叶片正面将卵产入叶肉组织内;成虫具较强的趋光、趋黄的特性。建议于成虫盛期悬挂黄板或开灯诱杀,于若虫1~2龄盛期施药进行防治。     

茶树品种抗茶橙瘿螨的形态与生化特征

不同抗螨性的茶树品种间存在着形态学和生物化学方面的差异。扫描电镜的观测结果表明,抗性品种在叶面形态上具有茸毛密度高、上表皮角质化程度强和气孔密度低的特点。鲜叶生化分析结果表明,抗性品种的氨基酸总量及组成中的茶氨酸、谷氨酸和天冬氨酸含量比感性品种高;此外,抗性品种还有较高的咖啡碱含量、低的还原糖和水溶性糖含量及较高的谷氨酸脱氢酶和苯丙氨酸解氨酶活性的生化特征。从抗螨机制的角度来说,形态学特征主要构成了螨取食行为的障碍因子,受遗传控制;而化学特征为一抗生性机制,易受环境条件的影响     

茶茎溃疡病的发生与防治技术研究

据陈宗懋报导,茶茎溃疡病（Phomopsis theae）最早是1917年在斯里兰卡发现,印度、肯尼亚、坦桑尼亚、马拉维、乌干达和我国浙江相继报道。2005年,首次在安徽省岳西县和石台县无性系茶园中发生,迄今未见成功防治茶茎溃疡病的报道。我们对该新病害进行了症状观察、病原鉴定、环境条件分析和侵染循环记载,研究了农业防治、生物防治和化学防治技术,及时控制了其传播与蔓延,取得了良好的效果。     

Biological characteristics of Pestalotiopsis versicolor，the agent of bayberry twig blight in Southern China

To study the biological characters of Pestalotiopsis versicolor, one of the agents of bayberry twig blight disease, the effects of media type, carbon （C） and nitrogen （N） sources, temperature, pH, and light on P. versicolor were examined to determine optimal conditions for mycelial growth and sporulation. Three independent isolates showed a similar trend of growth and sporulation with different C and N sources. However, the growth rates varied significantly among seven agar media. Fungal growth rates were the highest on potato dextrose agar （PDA） and potato sucrose agar （PSA）. The fungi grew fast on bayberry fruit extract agar （BFA） but sparsely. Growth rates were moderate on oatmeal agar （OMA） and Czapek\|Dox agar （CDA）, and low on bayberry leaf extract agar （BLA） and bayberry branch extract agar （BBA）. Sucrose, dextrose, maltose, lactose, mannose, levulose, sorbose, and starch were optimal carbon sources, whereas glycerol and ribose were moderate, and xylose was poor for the fungus. Potassium nitrate, ammonium nitrate, urea, and all of the amino acids tested （i.e. cysteine, glycine, tyrosine, histidine, alanine, arginine, glutamate, and proline）, were good sources of nitrogen for the fungus. Growth occurred between 10 and 30℃ and was optimal between 25 and 28℃. Growth was normal and no significant difference between pH 5 to 10 was found. The quantity of conidia from two isolates （XJ27 and XJ42） on PDA after 10 days growth under light was significantly greater （P< 0001） than that under darkness. In contrast, sporulation of the other isolate, RA2\|1, was unaffected by light. P. versicolor has wide adaptivity to media, carbon, nitrogen, temperature and pH, while light influences sporulation of some isolates. These results will be helpful to understand the epidemiology of the disease and to develop a reasonable disease management strategy in reforestation areas.