杀菌化合物对小麦纹枯菌生物测定标准初步研究

STUDIES ON THE BIOASSAY STANDARDIZATION OF ANTIFUNGAL COMPOUNDS TO RHIZOCTONIA CEREALIS

筛选小麦纹枯菌强致病力菌株R46(Rhizoctonia cerealis R46),制成不同的接种体接种中感纹枯病的小麦品种扬麦158,结果表明:用于生物测定的纹枯菌优势接种体为玉米砂与菌碟混合体;玉米砂菌丝混合体接菌量与小麦发芽率呈高度负相关。接种时期试验表明,在小麦第1叶长出前接菌,其病情指数较高;在蛭石基质营养液中总氮为15g·L^(-1)、总钾为1g·L^(-1)时小麦苗病情指数较高。离体测定多菌灵、丙环唑对小麦纹枯菌的活性表明,菌丝线性生长抑制法比菌丝干重抑制法更为敏感;活体生物测定表明,小麦纹枯菌对井冈霉素、多菌灵、丙环唑敏感。

A strong pathogenicity isolate of Rhizoctonia cerealis R46 was screened to inoculate wheat variety Yangmai 158 which was a medium sensitive to R. cerealis. Results showed that the superior inoculum was corn-vermiculite with R46 mycelium. The quantity of inoculator was high negatively correlative to germination rate of Yangmai 158. High disease index of wheat was found when wheat seedling was inoculated before the first leaf growth, and treated with a liquid nutriment of 1. 5 g · L-1 nitrogen and 1 g · L-1potassium in the corn-vermiculite. It was more sensitive for Carbendazim and Propiconazol to inhibition mycelium linear growth than dry weight in vitro. Carbendazim, Propiconazol and Jian-gangmycin showed sensitive to R. cerealis in vivo.