Early detection of Neophysopella tropicalis in grapevine leaves and on spore traps by qPCR

Neophysopella tropicalis, one of the causal agents of Asian grapevine leaf rust (AGLR), can cause severe epidemics in Brazil that lead to yield losses in commercial vineyards. An early detection of the pathogen by air sampling of urediniospores on spore traps or in symptomless leaves would be valuable to multiple studies, such as epidemics modelling, risk forecasting, monitoring of pathogen introductions in rust-free areas, and predicting the beginning of epidemics. This study developed a quantitative PCR (qPCR) protocol to quantify N. tropicalis urediniospores attached to adhesive tapes and in grapevine leaves before symptom appearance. A specific primer pair was designed based on the internal transcribed spacer (ITS) sequence region of the AGLR pathogen. Standard amplification curves using genomic DNA from urediniospores of N. tropicalis and from urediniospores attached to adhesive tapes were established. Grapevine leaves inoculated with N. tropicalis were collected at 2, 5, and 7 days postinoculation (dpi). One primer pair (580F/720R) amplified a 140 bp product in all AGLR isolates but did not amplify products of other rust genera, such as Phakopsora, Puccinia, Hemileia, Tranzschelia, Cerotelium, and Coleosporium. As little as 0.1 pg DNA and 10 urediniospores of N. tropicalis attached to adhesive tapes could be detected. qPCR enabled the detection of the pathogen as early as 2 dpi, before symptom appearance. This method can be used to monitor N. tropicalis inoculum in grapevine-growing areas and to quantify symptomless infections of the AGLR pathogen.     

Evaluation of the combination of 1,3-dichloropropene and dazomet as an efficient alternative to methyl bromide for cucumber production in China

BACKGROUND: The combination of 1,3‐dichloropropene (1,3‐D) and dazomet (DZ) offers a potential alternative to methyl bromide (MB) for soil disinfection. MB is scheduled to be withdrawn from routine use by 2015 in developing countries. Combination treatments of 1,3‐D + DZ were evaluated in a laboratory study and in two commercial cucumber fields. RESULTS: Laboratory studies found that nearly all of the tested combinations of 1,3‐D and DZ displayed positive synergistic activity on root‐knot nematodes (Meloidogyne spp.), two major soilborne fungi (Fusarium spp. and Phytophthora spp.) and the seeds of two major weed species (Digitaria sanguinalis and Abutilon theophrasti). Field trials revealed that the combination of 1,3‐D and DZ (at 10 + 25 g m^?2) successfully suppressed Meloidogyne spp. root galling, sharply reduced Fusarium spp. and Phytophthora spp. and maintained high cucumber yields. The combination treatment of 1,3‐D + DZ was more effective than 1,3‐D or DZ alone and provided results similar to methyl bromide with respect to pest control, plant mortality, plant height, yield and income. All of the treatments were significantly better than the non‐treated control. CONCLUSION: The results indicate that the tested combination of 1,3‐D and DZ offers an efficient alternative to methyl bromide for cucumber production. Copyright © 2012 Society of Chemical Industry     

东省不同地区玉米内生真菌的群落组成和多样性分析

为探究山东省玉米内生真菌的资源分布、群落组成及多样性,采用叶片组织分离法对山东省52个市县的玉米内生真菌进行分离纯化,通过内转录间隔区（internal transcribed spacer,ITS）序列分析技术进行内生真菌的种属鉴定,并分析内生真菌的群落组成和多样性。结果表明,共分离到857株内生真菌,隶属25个属,其中链格孢属Alternaria的菌株数量最多,为583株,占总菌株数的68.03%,其次为镰刀菌属Fusarium有71株,占总菌株数的8.28%;大部分地区的优势属为链格孢属,少数地区的优势属为镰刀菌属、炭疽菌属Colletotrichum和弯孢属Curvularia。不同地区的内生真菌定殖率变化很大,在12.50%~100.00%之间,平均定殖率为76.15%;陵城的多样性指数和均匀度指数最高,分别为1.74和0.97;莱芜的丰富度指数最高为2.22。山东省玉米内生真菌可以分为5个类群,其中黄河流域地区内生真菌定殖率相对较高。表明山东省玉米内生真菌种类丰富,不同地区间多样性水平存在差异。     

八种杀虫剂对黑粪蚊的防治效果及残留分析

选择8种杀虫剂,分别在实验室和菇房条件下研究其对黑粪蚊的防治效果和对平菇菌丝生长的影响,并分析施药后不同时间平菇中的农药残留.结果表明,40%辛硫磷EC、40%氧乐果EC、48%毒死蜱EC对黑粪蚊具有很好的防治效果,但对平菇菌丝的抑制率明显高于其它药剂;10%吡虫啉WP、4.5%高效氯氰菊酯EC不仅对黑粪蚊成、幼虫具有良好的防治效果,而且使用后对平菇菌丝生长的影响较小;2.5%高效氯氟氰菊酯EW、4.5%高效氯氰菊酯EC、1.8%阿维菌素EC等使用5天后均未检测到农药残留,5%氟虫腈SC和10%吡虫啉WP药后15天仍能检测到残留.     

不同季节土庄绣线菊根围丛枝菌根真菌群落差异性研究

土庄绣线菊(Spiraea pubescens)是内蒙古大青山干旱生态系统重要的护土灌木,研究季节变化对土庄绣线菊根围丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)群落的影响,有助于进一步探讨AMF在土庄绣线菊生长发育过程中发挥的作用。采用传统染色检测与Illumina Mi Seq测序相结合的方法,研究季节变化对内蒙古大青山土庄绣线菊AMF侵染率、孢子密度、丰富度、多样性和群落组成的影响。结果显示:在春季、夏季和秋季,AMF侵染率和丛枝丰度不存在显著差异,而孢子密度却存在显著差异。AMF丰富度和多样性在夏季显著低于春季和秋季,但在春季和秋季间差异并不显著;主成分分析(principal coordinate analysis,PCo A)和PERMANOVA分析表明,春季和秋季AMF群落组成与夏季存在显著差异,而在春季和秋季间差异并不显著。     

应用均匀设计法筛选稗草病原菌产孢最佳配方培养基

 筛选生防菌最佳产孢培养基是高效、大量生产生防菌孢子的基础。应用均匀设计法结合二次多项式回归分析,从众多因素中筛选出稗草病原菌弯孢菌(Curvularia lunata)和互格交链孢菌(Alternaria alternata)最佳产孢培养基组分,建立多元二次回归数学模型。弯孢菌最佳产孢组分为胡萝卜、芹菜、欧芹、水芹、莴苣、蔗糖和Vc;互格交链孢菌最佳产孢组分为胡萝卜、芹菜、水芹、莴苣和蔗糖。根据回归模型计算理论(拟和)产孢值。比较实测产孢量和理论产孢值,结果表明,稗草病原菌的实测产孢量和回归模型拟合产孢值非常接近,拟合误差小。说明采用均匀设计法从众多因素中筛选培养基最佳成分是可行的。     

食用菌生产企业社会责任与财务绩效的互动关系分析

食用菌生产企业的社会责任是决定企业可持续发展的关键因素,同时对企业的财务绩效存在多方面影响。基于已有文献研究结论,通过构建回归模型对食用菌生产企业社会责任与财务绩效的相关性进行分析。结果表明,食用菌生产企业对股东、供应商、消费者、政府和社区所承担的社会责任与财务绩效具有正相关关系;而食用菌生产企业对员工承担的社会责任与财务绩效的相关性不显著。     

金耳有效原种的配方和品种筛选

将生产中用到的两个金耳品种作为研究对象,将不同配方培养基中的菌丝、子实体生长状况进行对比,挑选出更适宜大规模生产的金耳品种,并探究麦麸在金耳有效原种制备中的必要性。研究结果显示,金耳1号菌丝较金耳2号更粗壮,长势更好,菌丝满瓶速度更快,子实体形态更好,更适合作为大规模生产的品种进行推广,且添加麦麸的配方更适合金耳1号原种生长。     

一种改进的尖孢镰刀菌的实时荧光定量PCR检测方法

为实现荧光定量PCR对土壤病原真菌数量更为高效、灵敏的检测,本研究将液体培养的孢子悬浮液和长年耕作的水稻土制作成孢子浓度为4×10~1~4×10~6 spore/g的带菌土,采用MoBio PowerSoil@DNA Isolation Kit提取模拟带菌土壤总DNA,引入常规PCR预扩增包含qPCR目标序列的1 446bp片段,以预PCR产物为模板进行qPCR,构建荧光定量PCR标准曲线。研究结果表明:以试剂盒提取的带菌土壤总DNA为模板绘制的qPCR标准曲线相关系数r为0.985,检测下限为4×10~3 spore/g土;引入预PCR后,qPCR标准曲线相关系数r为0.974,检测下限为4×10~2 spore/g土,较未引入时提高了10倍,结合不同土壤病原真菌的特异性引物,该检测方法可为土壤病原真菌的有效定量检测提供技术支撑。     

施加内生真菌拟茎点霉（Phomopsis sp.）对茅苍术凋落物降解及土壤降解酶活性的影响

通过向盆栽土壤中分别添加茅苍术(Atractylodes lancea (thunb) DC.)凋落物（CK）、内生真菌拟茎点霉（Phomopsis sp. 编号B3）和灭菌凋落物(MB)、内生真菌和凋落物(WB)、内生真菌和凋落物及菌体发酵液(WBF)、凋落物和灭菌发酵液 (WMF) 后,定期检测凋落物纤维素、木质素降解率,测定土壤纤维素酶和木质素酶活性,并利用巢式PCR方法跟踪土壤中活体内生真菌B3动态变化,研究了土壤施加内生真菌对掉落的茅苍术残体的分解及土壤降解酶活性影响。结果表明,植物内生真菌离开宿主进入土壤仍具有生理活性,能适应非宿主环境,存活30d之久。在此期间,内生真菌在富含凋落物的土壤中明显加快纤维素、木质素的降解,在10d、30d、60d取样测定,处理组中WBF和MB的土壤纤维素酶活性显著高于其他处理组,处理组MB和WB的土壤木质素酶活性显著高于其他处理组。