掌叶半夏茎基腐病病原鉴定及其防治药剂筛选

茎基腐病是河北省安国市掌叶半夏（Pinellia pedatisecta）生产中为害较严重的多发性病害,对该病害的病原菌进行了分离、鉴定、致病性测定和防治药剂的筛选。通过形态鉴定和rDNA-ITS序列分析,将安国掌叶半夏茎基腐病的病原菌鉴定为瓜果腐霉（Pythium aphanidermatum）。选用5种常用化学杀菌剂、2种生物杀菌剂和玫瑰黄链霉菌Men-myco-93-63抗生素粗提物对Py. aphanidermatum进行室内毒力测定,结果表明：35%精甲霜灵ES、玫瑰黄链霉菌Men-myco-93-63抗生素粗提物、40%氟硅唑EC、99%恶霉灵TC对瓜果腐霉菌丝的生长具有较明显的抑制作用,EC₅₀分别为12.81、41.74、54.16和56.90μg/mL;而1×10 ¹¹芽孢/g枯草芽孢杆菌WP、1×10 ⁶孢子/g寡雄腐霉菌WP、3%甲霜·恶霉灵AS和50%烯酰吗啉WP对该病菌的抑制效果不明显。

Pathogen Identification and Fungicide Screening of Stem Base Rot Disease on Pinellia pedatisecta

Stem base rot is a serious disease with high incidence rate on the production of Pinellia pedatisecta in Anguo city, Hebei Province. Isolation, identification, pathogenicity and screening of its fungicides were carried out in our study. The pathogen was identified as Pythium aphanidermatum through measuring morphological characteristics and rDNA-ITS sequence analysis. Toxicity of five common chemical fungicides, two biological fungicides and crude antibiotic extracts of Streptomyces roseoflavus Men-myco-93-63 to Py. aphanidermatum was determined in laboratory. The results showed that 35% metalaxyl-M ES, crude antibiotic extracts of S. roseoflavus Men-myco-93-63, 40% flusilazole EC, and 99% hymexazol TC had certain inhibition with EC₅₀ of 12.81, 41.74, 54.16, and 56.90μg/mL respectively. While the inhibitory effects of 1×10 ¹¹ spores per gram Bacillus subtilis WP, 1×10 ⁶spores per gram Py. oligandrum WP, 3% metalaxyl·hymexazol AS and 50% dimethomorph WP were not obvious.