藜麦种质资源对霜霉病的抗性鉴定与评价

为探究藜麦(Chenopodium quinoa)种质资源在本土环境条件下对霜霉病的抗性，采用田间自然感病和室内离体叶片接菌鉴定方法对50份国内外藜麦种质资源进行了霜霉病抗性鉴定和评价。结果表明：霜霉菌Preonos variabilis对藜麦的侵染程度存在较大变异(发病率变化13.30%～100.00%；病情指数1.00～100.00)，藜麦种质对霜霉病的抗性存在明显差异；筛选到1份高抗材料'台湾红藜’，占参试材料的2.00% 1份抗病材料'QA064’，占比2.00%，2份中抗材料'陇藜2号’和'HL-Q5’，占比4.00%，3份感病材料'QA045’'QA050-2’和'青海-02’，占比6.00%；其余43份材料均表现高感，占比86.00%。本研究首次发现'台湾红藜’能够被P. variabilis侵染，表现为高抗，还进一步证实田间藜麦霜霉病抗性鉴定采用“三叶法”在藜麦盛花期进行效果较好，相比而言，室内离体叶片接菌鉴定技术更具优势，应作为抗性鉴定的首选。     

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.     

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。