NGHIÊN CỨU NẤM PHẤN TRẮNG (Microphaera diffusa) HẠI ĐẬU TƯƠNG Ở MIỀN BẮC VIỆT NAM

The powdery mildew was collected from 6 provinces in the North of Vietnam including Ha Noi, Ninh Binh, Vinh Phuc, Ha Nam and Ha Giang. The powdery mildew isolates collected from 6 different provinces were conducted to indicate number of fungal species responsible for the cause of powdery mildew. This study of Fungal morphology was conducted basing on method of Yukio Sato (2005). The powdery mildew disease was observed on 250 soybean accessions in the field condition and 200 accessions in artificial infection. The disease was evaluated with cycle from 0 to 5 scale. Results show that: The powdery mildew fungus belongs to the mitosporic genus Oidiumsub-genus Pseudoidium. There are 8 phenotypes of soybean highly resistant to powdery mildew disease at score 0 and 26 phenotypes at score 1. These accessions will be used for breeding of soybean lines/varieties resistant to powdery mildew.