防治杨树溃疡病内生菌的分离筛选及鉴定

为筛选到对杨树溃疡病有良好生防效果的拮抗菌,采用平板对峙法初筛、发酵液“三明治”法和改良琼脂扩散法复筛,以及离体组织试验对杨树不同部位组织的内生菌进行了分离筛选,并对目的菌株进行了防治效果测定;采用形态学观察和ITS序列及其系统发育树分析对其进行初步鉴定。结果表明从115株杨树内生菌中筛选出有拮抗效果的菌株24株,并复筛出拮抗效果良好的菌株5株,最终从杨树内生菌中筛选出1株杨树溃疡病拮抗真菌,编号为YGF9,其对杨树离体组织溃疡病防治效果可达76.47%,初步鉴定该菌株为黄绿木霉Trichoderma aureoviride。表明菌株YGF9可有效抑制杨树溃疡病病原菌的生长,是防治杨树溃疡病的潜在生防菌株。     

Assessment of Non-chemical Alternatives for Controlling the Burrowing Nematode on Banana in Costa Rica

The objective of this study was to technically and economically assess the effect of biopesticides on the serious plant parasitic nematode Radopholus similis on banana in Costa Rica. The following treatments were evaluated： a mixture of nematode trapping fungi-Arthrobotrys oligospora, A. botryospora, Dactylella brochophaga and Drechmeria coniospora; DiTera DF which consist of a ＂dead＂ fungus Myrothecium spp. and its fermentation substrate; Savitan produced from desert plant extracts; QL Agri which contain Quillaja saponaria extracts; Japanese-style compost called Bokashi; two application of a chemical nematicide; and an absolute control. Results of root sampling on a six month basis showed that the biopesticides had lower nematode population densities than the control with the nematode trapping-fungi having statistically significant differences over the other treatments. Chemical control was highly effective and produced the lowest nematode density. However, there were no significant differences between the chemical treatment and the trapping-fungi treatment. The functional root weight and bunch weight showed no significant differences between treatments. Conversely, economic analyses indicated that using nematode trapping-fungi, chemical nematieide, or the QL Agri treatments gave a detectable profit. The land expectation value （LEV） of the banana plantation was higher than the price of banana land which indicated that under normal conditions in the banana sector, production is economically sustainable / profitable. Other results confirm that profit in banana production is affected by the price of a banana box, production and discount rate. The optimal production cycle was obtained in year ten after farm establishment, which refers to the year with the highest profit following plantation renewal. Finally, economical results highlighted the importance of nematodes control, since profitability indexes were sensitive to the efficiency and cost of nematode management technology adopted by the banana company.     

梨小食心虫的天敌资源

对文献资料中的梨小食心虫天敌和山西太谷县主要果品产区的天敌资源进行了调查,查明梨小食心虫天敌共255种,其中,寄生性252种(中国48种),捕食性3种,分属昆虫纲(膜翅目、双翅目、缨翅目、鞘翅目)和蛛形纲(蜱螨目),共5个目20个科,具有应用潜力的天敌昆虫7种,已经成功应用于生产中的天敌昆虫5种;山西省分布共10种,均为膜翅目寄生性天敌,在太谷县分布有3种,其中,齿腿姬蜂属(Pris-tomerus sp.)和瘤姬蜂属(Pimplini sp.)可以与梨小食心虫同时羽化。     

根结线虫的生物防治研究进展

根结线虫分布广泛且危害严重,已成为近年来植物病虫害防治的重点。详细阐述了根结线虫的致病机理,综述了几种防治根结线虫的途径,并对其生物防治前景进行了展望。     

花角蚜小蜂对松突圆蚧的防治

根据近年来泉州市应用花角蚜小蜂防治松突圆蚧的工作实践,总结了应用花角蚜小蜂防治松突圆蚧的主要技术措施,包括林间放蜂点的选择和管护、室内收蜂、补充营养与配对、林间放蜂、效果检查与巩固等,为推广应用花角蚜小蜂生物防治提供参考。     

拮抗水稻白叶枯病菌链霉菌的筛选、鉴定和防效研究

 为寻找水稻白叶枯病天然生防药剂,本研究利用共培养和牛津杯法分离筛选植物根际土壤放线菌,共分离纯化获得65株放线菌菌株。在8株能够拮抗水稻白叶枯病菌Xanthomonas oryzae pv. oryzae (Xoo)放线菌菌株中,Sr-63菌株对水稻白叶枯病菌拮抗能力最强,其发酵液抑菌圈直径为46.4 mm ± 2.3 mm。优化发酵条件后,Sr-63菌株发酵液抑菌圈直径可达50.0 mm ± 1.2 mm;依据形态特征、生理生化特征和系统发育分析,鉴定菌株Sr-63为玫瑰轮丝链霉菌(Streptomyces roseoverticillatus)。抗菌谱实验结果表明,Sr-63菌株发酵液对水稻细菌性条斑病菌、大豆细菌性斑疹病菌、番茄细菌性叶斑病菌以及大豆细菌性斑点病菌4种植物病原细菌也有较好的拮抗作用。水稻白叶枯病防效实验结果表明,Sr-63菌株发酵液对水稻白叶枯病具有良好的防治效果,对‘Chai Nat 2'、‘KDML105'、‘Khao luang' 3个水稻品种的病斑抑制率均达到了90 %以上,且Sr-63菌株的发酵液防治效果优于化学农药叶枯唑。     

蠋蝽对荔枝蝽一龄若虫的捕食功能反应

为了筛选在荔枝蝽若虫期对其具有良好防效的天敌昆虫，本试验探究蠋蝽对荔枝蝽1龄若虫的捕食潜力，在室内条件下评价了蠋蝽4龄若虫、5龄若虫、雌成虫和雄成虫对荔枝蝽1龄若虫的捕食能力，结合果园的观察总结了蠋蝽捕食行为特点。结果表明：蠋蝽4龄若虫、5龄若虫、雌成虫和雄成虫对荔枝蝽1龄若虫的捕食功能反应符合Holling Ⅱ模型，对荔枝蝽若虫的日最大捕食量分别为9.066、8.210、8.354和5.903头，瞬时攻击率分别为0.956、1.327、1.100和1.244，处理时间分别为0.10、0.162、0.132和0.149 d。不同龄期蠋蝽对荔枝蝽1龄若虫的搜寻效应均随猎物密度的增大而减小。室内外观察发现，蠋蝽捕食荔枝蝽若虫时的行为和捕食草地夜蛾等其他猎物时相似，经历搜索、跟随、攻击、取食、转移等行为反应。捕食功能试验证实蠋蝽对荔枝蝽1龄若虫具有较高的控害潜能，是实现荔枝蝽绿色防控的一种良好备选天敌产品。     

玫烟色棒束孢FZ-01鉴定及对烟粉虱的防治潜力评估

为了明确从罹病烟粉虱Bemisia tabaci上分离的虫生真菌（菌株FZ-01）的分类归属及其生物防治的潜力，采用形态学特征观察和rDNA-ITS序列分析方法对该菌株进行鉴定，并对其生物防治潜力进行评估。结果发现：菌株FZ-01为玫烟色棒束孢Isaria fumosorosea；该菌株在马铃薯PDA培养基上生长良好；适应温度和酸碱度范围较广，可耐高温（35℃）和酸碱（pH4～10）；孢子萌发速率快（5 h）且萌发率高（>90%）；菌株致病力测定表明分生孢子浓度为1.0×10⁷ cfu/mL时，对烟粉虱（MEAM1）成虫致死中时间（LT₅₀）仅为2.75 d，接菌4 d时致死中浓度（LC₅₀）仅为2.69×10⁴ cfu/mL。综上结果表明，玫烟色棒束孢FZ-01对烟粉虱具有十分优良的生防潜力。     

花角蚜小蜂对松突圆蚧的防治

根据近年来泉州市应用花角蚜小蜂防治松突圆蚧的工作实践,总结了应用花角蚜小蜂防治松突圆蚧的主要技术措施,包括林间放蜂点的选择和管护、室内收蜂、补充营养与配对、林间放蜂、效果检查与巩固等,为推广应用花角蚜小蜂生物防治提供参考。