Detection of airborne inoculum of Leptosphaeria maculans and Pyrenopeziza brassicae in oilseed rape crops by polymerase chain reaction (PCR) assays

The potential use of DNA-based methods for detecting airborne inoculum of Leptosphaeria maculans and Pyrenopeziza brassicae , both damaging pathogens of oilseed rape, was investigated. A method for purifying DNA from spores collected using Hirst-type spore samplers and detecting it using polymerase chain reaction (PCR) assays is described. For both pathogens, the sensitivities of the DNA assays were similar for spore-trap samples and pure spore suspensions. As few as 10 spores of L. maculans or P. brassicae could be detected by PCR and spores of both species could be detected against a background of spores of six other species. The method successfully detected spores of P. brassicae collected using spore traps in oilseed rape crops that were infected with P. brassicae. Leptosphaeria maculans spores were detected using spore traps on open ground close to L. maculans -infected oilseed rape stems. The potential use of PCR detection of airborne inoculum in forecasting the diseases caused by these pathogens is discussed.     

异色瓢虫工厂化繁育技术研究

利用自动化温室大棚,研究了异色瓢虫对不同寄主蚜虫的取食量和不同温度下异色瓢虫产卵情况,结果表明：白菜蚜虫为异色瓢虫最佳饲料,25℃是异色瓢虫最佳产卵温度,利用自动控温大棚可以周年种植白菜,培育白菜蚜虫,实现了异色瓢虫周年工厂化繁育。     

甘蓝夜蛾人工饲料的研究

文章报道了以甘蓝叶、白菜叶、灰菜叶、大豆粉、菜豆粉、玉米粉、麦麸为主要原料配制的5种人工饲料对甘蓝夜蛾的饲养效果。结果表明,以甘蓝叶和大豆粉为主要原料配制的配方—人工饲料对甘蓝夜蛾饲养效果最好,甘蓝夜蛾不仅能正常生长发育,而且在产卵量、蛹重、幼虫存活率方面均优于天然饲料,用该人工饲料连续饲养4代甘蓝夜蛾,未发现饲养后代生命力减退现象,表明该人工饲料可用来室内大量连续饲养甘蓝夜蛾。     

甘蓝型油菜MYB28转录因子对根肿菌和水杨酸的响应特征

MYB转录因子参与植物的生长发育和逆境胁迫过程,在植物防御相关信号反应中起着重要的调控作用。 为了明确MYB28在油菜与根肿菌互作中的作用,对感病甘蓝型油菜中双11中MYB28家族基因在根肿菌接种以及 水杨酸处理后的表达模式进行了分析。不同组织表达模式分析显示,相比于根和叶,BnaMYB28 在茎和种子中的表 达水平更高;BnaMYB28 基因在根肿菌和外源水杨酸处理下均有不同程度的表达响应,外源水杨酸处理下Bna⁃ MYB28-1 和BnaMYB28-3 上调表达,BnaMYB28-2 表达则受抑制。根肿菌侵染后,BnaMYB28-1 在整个侵染期表达 量均显著上调,但在加入水杨酸后表达被显著抑制;BnaMYB28-3 表达量在接菌后7 d和28 d显著上调,在关键皮层 侵染期（接菌后14 d）表达量与对照组相比没有变化,但在施加水杨酸处理后表达量显著上调。综上,外源水杨酸能 正向调控BnaMYB28-1 和BnaMYB28-3 表达,BnaMYB28-3 可能通过水杨酸信号路径参与油菜与根肿菌的互作。     

Quantitative studies on the relationship between plowing into soil of clubbed roots of preceding crops caused by Plasmodiophora brassicae and disease severity in succeeding crops

The effect of the plowing of clubbed roots of cracifers on the population of Plasmodiophora brassicae in soil was quantitatively studied by measuring the number of resting spores produced in the diseased plants. Though the mean number of resting spores per diseased plant increased with the increase of the disease severity, it remained almost identical for the disease severity classified into category 3 among host species and cultivars tested. Mean number of resting spores per diseased plant ranged from 9.3 to 10.9 (log) regardless of the value of the disease index. When the number of resting spores in soil was calculated based on these data and plant cultivation methods, the values were equivalent to 4.8-6.4 resting spores g^-1soil (log)where clubroot disease occurred severely. The value of the disease index of Chinese cabbage plants grown in the pots where clubbed roots of initially grown plants had been plowed into soil (plowing plot) was higher than that in the pots where no plants had been grown (control plot) and where the clubbed roots of initial plants had been removed (removal plot). Though the number of resting spores of P. brassicae in soil decreased by 14% of the inocoKum concentration immediately after the inoculation, the number of spores after the first cultivation in the removal plot was similar to that in the control plot. On the other hand, the number of resting spores in the plowing plot increased significantly compared with that in the control plot. The plowing of clubbed roots into soil resulted in the increase of the population of P. brassicae and disease severity of clubroot in subsequent cultivation in the field. The results corresponded to the values estimated based on the number of resting spores in soil in relation to each value of the disease index.     

西南地区油菜品种根肿病抗性及布局分析

为明确西南地区主栽油菜品种根肿病抗性,以期为合理品种布局提供依据,降低根肿病的危害和损失。结合病圃根肿病菌生理小种鉴定,在四川安县、大邑、广汉三地区,采用病圃自然发病法,对80个油菜品种进行根肿病抗性评价,并对22个品种连续3年进行抗性跟踪。结果表明：三地区病圃根肿菌为存在基因型分化的4号生理小种;供试油菜品种中无免疫根肿病品种,安县、大邑、广汉三地感病品种分别占比88.75%、83.75%、87.50%,其中55个品种在三地区均表现感病,即不适宜在根肿病菌为4号生理小种区域种植;抗性跟踪评价显示不同品种的抗性稳定性存在差异。‘浙油50’、‘油罐罐’适宜安县地区种植,‘黄金荚’、‘金油858’、‘油研9号’、‘种都油998’和‘渝黄4号’适宜大邑地区种植,‘志远油8号’适宜广汉地区种植。‘绵丰油5号’、‘德名油1号’表现抗性丧失趋势;‘丰油精’、‘高油48’抗性不稳定;‘矮架早’抗性完全丧失。     

绿色荧光蛋白标记解淀粉芽孢杆菌Bam22在油菜体内的定殖

研究GFP标记的解淀粉芽孢杆菌Bam22在油菜植株上的定殖规律,为其开发利用提供科学依据.采用自然转化法将携带绿色荧光蛋白基因的质粒pGFP4412导入Bam22细胞中,构建GFP荧光标记菌株;对比野生型菌株Bam22与标记菌株Bam22-GFP的生长曲线和抑菌能力;通过灌根法,观察标记菌株在油菜体内不同组织部位的定殖...     

十字花科蔬菜根肿病菌的PCR检测

 利用设计合成的1对根肿病菌（Plasmodiophora brassicae）特异性寡聚核苷酸引物（前引物:5’GAA GAT GCC CAC GCC GTC GT3’和后引物:5’ATC TGT TCA GCA AAG CGT CGA3’）,对分离自十字花科作物（白菜、青菜、甘蓝、芥蓝、花椰菜等）及土壤中的根肿病菌全基因组DNA进行PCR（Polymerase Chain Reaction）特异性扩增试验。试验结果表明,试验设计合成的引物能从十字花科根肿病菌全基因组DNA中扩增到629 bp长度的分子片段,该对引物可用于十字花科蔬菜根肿病的分子鉴定和分子监测,为十字花科根肿病的早期准确诊断和病菌检测提供了快速、简便的方法。     

十字花科根肿病菌在不同温度、pH值条件下致病性差异研究（英文）

[目的]探讨十字花科白菜根肿病菌在不同温度、pH值条件下致病性。[方法]采用根肿病菌和土壤混合法,在休眠孢子浓度1×108(个/g土)条件下,设置7个温度及6个土壤pH值梯度,进行根肿病菌对白菜致病性测定,90 d后拔根调查根肿病菌侵染发病情况。[结果]在pH值6时,不同温度梯度间白菜根肿病发病株率存在较大差异,其发病株率从高到低的温度为30℃25℃20℃35℃15℃10℃5℃。5℃和10℃条件下,其根肿病菌侵染力弱,不发病或发病株率较低;15~30℃条件下随温度升高发病率增加,但在35℃条件下,发病株率降低。温度25℃条件下,pH值为4、5、6、7、8、9的白菜发病株率分别为80.36%、100%、65%、10.77%、3.23%、0.0%。pH值4发病率虽高,但白菜生长受抑制,生长弱,存活率低。pH值7和8时,发病率较低,pH值9时没有发病,在pH值5和6时,植株生长良好,发病率也较高。[结论]该研究结果表明根肿病菌侵染发病与温度、土壤pH值关系密切。     

复合型甘蓝夜蛾核型多角体病毒对三种夜蛾的室内毒杀试验

复合型甘蓝夜蛾核型多角体病毒是由甘蓝夜蛾核型多角体病毒(MbNPV)与苜蓿银纹夜蛾核型多角体病毒(ACNPV)按0.5∶1复合而成的。为了掌握其对甘蓝夜蛾的毒杀效果,用蒸馏水将其稀释成2.0×10~3、2.0×10~4、2.0×10~5、2.0×10~6、2.0×10~7PIB·mL~(-1)五个所需的浓度进行测试,并用方差分析和新复极差法测验。结果表明:复合型甘蓝夜蛾核型多角体病毒对斜纹夜蛾、甜菜夜蛾、甘蓝夜蛾毒杀效果差异显著。饲毒后第2天,甘蓝夜蛾对复合剂较敏感;饲毒后第3天对复合剂敏感性均增强;饲毒后第4天,甘蓝夜蛾、甜菜夜蛾死亡率均在80%以上,斜纹夜蛾死亡率在60%以上。