松突圆蚧生防菌的毒力试验

将广西大学林学院提供的菌株喷施于被松突圆蚧侵染的松树树冠上,结果表明:5种生防菌对松突圆蚧的致死率均远远高于松突圆蚧的自然死亡率,防治效果显著。第1次试验进行后的第125天和第2次试验进行后的第85天再次对松突圆蚧的死亡率进行统计,结果表明菌液对松突圆蚧的防治作用可以持续4个月左右。     

白桦木材变色生防菌的筛选研究

木材变色病原菌易引起木材变色,使木材发生降等。笔者采用从白桦原位土壤及自身组织分离纯化的方法,寻找对白桦变色病原菌具有拮抗作用的生防菌。经过改良5点对峙试验,筛选出对白桦木材变色5种病原菌具有拮抗作用的生防菌菌株共42株,其中x18及x26对5种病原菌都具有明显的拟制效果,菌落抑菌圈半径最大达2.1 cm。     

40种植物甲醇提取物的杀螺活性研究

对40种药用或有毒植物甲醇提取物的室内杀螺活性测定结果表明:木荷、黄姜、博落回等3种植物提取物在浓度为100mg/L时,浸杀福寿螺幼螺48h,死亡率为100%;50mg/L时,浸杀72h,死亡率为98.28%以上。其中木荷、博落回对福寿螺有良好的抑制上爬作用,具有进一步研究价值。     

Influence of calcium propionate on the control of post-harvest rots of jujube and the biocontrol activity of an antagonistic yeast

The effect of calcium propionate (CaP) on post-harvest pathogens of winter jujube (Zizyphus jujuba Mill.), and on improving the efficacy of the biocontrol yeast, Metschnikowia pulcherrima, were evaluated. In vitro, CaP at ≥2% (w/v) had significant inhibitory effects on spore germination and germ-tube growth in Penicillium citrinum and Alternaria alternata. However, the application of 2% (w/v) CaP did not affect population growth of M. pulcherrima in nutrient yeast dextrose in vivo. With or without CaP, yeast cell numbers increased after 72 h by approx. 11.1-fold and 13.4-fold, respectively. The concentration of the antagonistic yeast suspension influenced the incidence of both pathogens and lesion development on jujube fruit, and the effect increased with an increase in yeast cell concentration. A combination of the antagonistic yeast plus 2% (w/v) CaP resulted in a lower incidence of disease and smaller lesion diameters compared to treatments with the antagonistic yeast alone. In this case, the incidence of disease was reduced by 16.8–27.3% for P. citrinum and by 25.2–31.4% for A. alternata. Lesion diameters on these fruit were 2.7–6.2 cm and 1.8–2.4 cm for P. citrinum and A. alternata, respectively. Calcium propionate had a consistent ability to enhance the biocontrol activity of M. pulcherrima against blue mould (P. citrinum) and Alternaria rot on jujube fruit. Thus, the application of 2% (w/v) CaP could be a useful approach to improve the efficacy of the antagonistic yeasts used for post-harvest disease control in jujube.     

苏云金杆菌无鞭毛菌株7805的研究

7805菌是从梅白蝶幼虫尸体分离出的一株苏云金杆菌,无鞭毛,其特性与武汉变种有明显的区别,认为是一新变种,暂命名为苏云金杆菌武汉变种甘肃品系(Bacillus thuringiensis var.Wuhanensis gansu7805)。此菌对梅白蝶、菜青虫、沙枣尺蠖,稻苞虫等防效比较显著,应用含活孢子0.125～0.5亿/毫升的菌液,防效达85～100％。     

香蕉枯萎病生防细菌ZJ6-6的盆栽防治效果及其生防基因分析

通过病原菌和生防菌人工接种方法测定生防细菌ZJ6-6对香蕉枯萎病的盆栽防治效果,扩增和序列分析ZJ6-6的生防基因。结果表明：ZJ6-6处理香蕉的萎缩指数和导管褪色指数比对照香蕉分别降低40.5%和43.9%,其对香蕉枯萎病具有显著防治效果;ZJ6-6至少含有6个生防基因ituD、lpa-14、bmyB、fenD、srfAA、srfAB,理论上具有合成脂肽抗生素的能力,这可能是其能防治香蕉枯萎病的原因。本研究结果对ZJ6-6合成分泌的抗菌物质鉴定及其生防机理研究具有重要意义。     

高粱枯萎病生防菌株筛选研究

由半裸镰刀菌引起的高粱枯萎病是一种严重的土传病害,为了有效地抑制高粱枯萎病的发生,筛选出对该病害具有较强抑制活性的生防菌株.从黑龙江省大庆市土壤中分离出33种生防菌,采用平板对峙法从33种菌株中筛选出对半裸镰刀菌具有抑制作用的生防菌株,并进行盆栽高粱接菌试验,通过高粱枯萎病的病情指数与发病率调查,筛选出4种拮抗细菌Y+...     

Identification and Pathogenicity of a New Entomopathogenic Fungus,Mucor hiemalis (Mucorales: Mucorales), on the Root Maggot,Bradysia odoriphaga (Diptera: Sciaridae)

Bradysia odoriphaga Yang and Zhang (Diptera: Sciaridae), the Chinese chive root maggot, is a destructive pest of Allium vegetables and flowers that causes severe losses in northern China. Novel biological control technologies are needed for controlling this pest. We identified a new entomopathogenic fungus isolated from infected B. odoriphaga larvae and evaluated the susceptibility of the biological stages of B. odoriphaga and the effects of temperature on fungus growth and pathogenicity. Based on morphological characteristics and molecular phylogeny, the fungus was identified as Mucor hiemalis BO-1 (Mucorales: Mucorales). This fungus had the strongest virulence to B. odoriphaga larvae followed by eggs and pupae, while B. odoriphaga adults were not susceptible. A temperature range of 18–28°C was optimum for the growth and sporulation of M. hiemalis BO-1 and virulence to B. odoriphaga larvae. At 3 and 5 d after inoculation with 10⁵ spores/ml at 23°C, the survival rates were 24.8% and 4.8% (2nd instar larvae), respectively, and 49.6% and 12.8% (4th instar larvae), respectively. The potted plant trials confirmed that M. hiemalis BO-1 exerted excellent control efficiency against B. odoriphaga larvae, and the control exceeded 80% within 5 d when the spore concentration applied exceeded 10⁷ spores/ml. In conclusion, these findings supported the hypotheses that this fungus could serve as an effective control agent against B. odoriphaga larvae and is worth being further tested to determine its full potential as a biocontrol agent.     

双功能木霉突变菌株的筛选和功能分析

研究从木霉菌REMI突变株中筛选到16株对氰化物具有明显降解活性,将其与5种常见病原菌对峙培养,得到7株拮抗性较高的突变株。对这7株转化子进行盆栽试验表明:多数供试转化子对黄瓜幼苗枯萎病具有明显的防效,其中转化子TkA8的防治效果最好,达到了73.5%。同时研究发现TkA8处理黄瓜幼苗可诱导防御反应相关酶系PAL、POD活性明显增加,分别为对照的3.21和4.25倍。因此TkA8是一种具有防病和生物修复氰化物污染的较理想的多功能木霉菌株。     

烟草赤星病拮抗细菌的筛选及其控病作用

从烟草叶片上分离到236株非病原细菌,通过平板对峙培养,筛选出对不同致病力的烟草赤星病菌Alternaria alternata(Fr.)Keissl均有拮抗作用的菌株:Ata28、Ata81、Ata124和Ata160.室内测定其对赤星病菌抑菌带的宽度达6.1～10.5mm;室内离体叶片悬滴法测定,提前喷施拮抗菌其防治效果为53.9%～73.0%;接赤星病菌后喷施的防治效果为44.0%～60.0%;在温室中进行盆栽防病试验,防治效果为52.3%～75.8%.无菌滤液试验表明,拮抗菌Ata28无菌滤液在一定浓度范围内均能有效地抑制菌丝生长,减少孢子萌发,且浓度越高,抑制能力越强.