腐烂茎线虫对当归细胞结构和生理特性的影响

为了明确当归受到腐烂茎线虫(Ditylenchus destructor)侵染后其根部细胞结构和叶部生理特性的变化,本试验以'岷归1号'和腐烂茎线虫为材料,采用田间自然发病条件测定了腐烂茎线虫侵染后当归根部细胞结构,以及叶部生理特性的变化规律.徒手切片光学显微镜观察结果表明,腐烂茎线虫侵染后,根部发病部位细胞受到严重破...     

青海省青稞根腐病调查及病原菌鉴定

为明确青海省青稞根腐病发生情况及其病原菌,于2016年6—9月对青海省海北藏族自治州海晏县、刚察县,海东市互助土族自治县苗期及成株期青稞上根腐病发生情况进行调查,采集19份根腐病样品,采用常规组织分离法对样品进行分离,并对分离菌株进行致病性测定,通过形态学特征及分子生物学方法对其进行鉴定。结果显示,青海省青稞根腐病分布广泛,发病率较高,为10%～20%;发病植株长势弱、发黄,茎基部缢缩腐烂,穗白粒瘪,茎秆发褐或黑红;19份样品中共分离纯化得到93株病原菌菌株,其中73株为燕麦镰孢Fusarium avenaceum,9株为木贼镰孢F. equiseti,11株为锐顶镰孢F. acuminatum;木贼镰孢的绝对病情指数最强,为79.43,燕麦镰孢次之,为50.90,锐顶镰孢最弱,为23.70,各病原种间及种内致病性差异显著。根据分离率及各病原菌致病性综合确定燕麦镰孢为青海省青稞根腐病的优势病原菌。     

Identification and biological characterization of the pathogens responsible for sclerotinia rot in Codonopsis pilosula北大核心CSCD

The aim of this study was to isolate and characterize the causal pathogen and study the biological characteristics of sclerotinia rot of Codonopsis pilosula. Pathogen material was obtained by tissue isolation. The isolated fungal species were comprehensively evaluated in terms of their morphology，rDNA-ITS sequence，RPB2 gene of RNA polymerase Ⅱ，and biological characteristics. The pathogens were identified as Sclerotinia nivalis and Sclerotinia sclerotiorum，and of the two，S. nivalis was the dominant species. The optimum temperatures for mycelium growth and sclerotia formation of S. nivalis were 20 and 15 ℃，respectively，while corresponding values for S. sclerotiorum were 25 and 25 ℃ . The optimum pH for mycelium growth was 6 for both species，while optimum pH for sclerotia formation was 6 for S. nivalis and 7 for S. sclerotiorum. The optimum culture medium was 100% potato dextrose agar（PDA）. The mycelial growth rate approach was applied to test the toxicity of adiacylamine， which exhibited inhibitory activity with EC50 on S. nivalis at 0. 2625 mg·L-1 and on and S. sclerotiorum at 0. 4165 mg·L-1. In summary，this is the first report of S. nivalis and S. sclerotiorum causing sclerotinia rot on C. pilosula in China，and the data presented provide a reliable scientific proof of the pathogen diagnosis and a theoretical basis for the development of prevention measures. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

甘肃省黄芩白粉病病原鉴定及对黄芩叶片生理特性的影响

为探讨黄芩白粉病的发病症状、病原种类及对黄芩叶片生理特性的影响，从甘肃省定西市陇西县黄芩主产区采集黄芩白粉病病叶，通过病原菌无性和有性形态特征观察并结合rDNA-ITS序列分析对其进行种类鉴定。结果表明：引起甘肃省黄芩白粉病的病原菌为琉璃草高氏白粉菌(Golovinomyces cynoglossi)，该病菌能引起室内黄芩白粉病，发病黄芩叶片电解质渗漏电导率升高，叶绿素含量降低；发病黄芩植株叶片总灰分、Zn、Mn、Cu、Fe、Ca、Mg、全P和全B的含量升高，而蛋白质、总糖、可溶性糖、全N、全K的含量降低。在国内首次报道了琉璃草高氏白粉菌(G.cynoglossi)引起黄芩白粉病，明确了白粉病对黄芩叶片生理特性的影响。     

不同药剂对青稞根腐病的田间防效评价

为筛选安全高效、经济适用的青稞根腐病防治药剂，选取12种常用低毒药剂，对青稞品种藏青2000采用拌种或浸种处理进行田间防治试验，结合不同处理物候期、倒伏率、发病率、农艺性状及产量等指标，并基于千粒重、产量及根腐病发生率进行Topsis综合评价。结果表明，不同药剂处理均能有效降低根腐病发生率，其中用50%克菌丹可湿性粉剂2.40 kg/hm²拌种处理综合评价最优，施用后青稞未发生倒伏，根腐病发生率为5.00%，适宜于根腐病发病严重区域推广使用。1亿活芽孢/g的枯草芽孢杆菌微囊粒剂和50%吲唑磺菌胺水分散粒剂拌种处理的青稞根腐病发病率均为6.67%，折合产量分别5 900、5 190 kg/hm²。其中枯草芽孢杆菌微囊粒剂拌种处理的增产率最高，为8.19%，更适宜于大面积推广。