Resistance Potential to Powdery Mildew (Microsphaera Diffusa Cooke and Peck) of Several Yellow and Black Soybean (Glycine Max (L.) Merr) Genotypes

Powdery mildew caused by Microsphaera diffusa has recently received more attention because of yield losses caused by the disease and has even been reported as a limiting factor on soybean production in a certain soybean plantation areas. The aim of the research was to examine resistance potential of several yellow and black soybean genotypes in order to develop powdery mildew-resistant soybean varieties. The experiment was conducted in rainy season of 2013 at the Ciparanje Experimental Station, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, West Java, using a Randomized Block Design with 61 soybean genotypes as treatments that replicated two times. Each genotype was planted in plot (5 m long) consisted of 25 plants from which 6 plants per plot were sampled randomly. The disease intensity and soybean yield were assessed. The result showed that 15 genotypes were not infected by the disease, namely UP-104, UP-106, UP-108, UP-111, UP-112, UP-113, UP-114, UP-125, UP-127, UP-130, UP-136, UP-137, Argomulyo, Arjasari and Mintani, whereas other 46 genotypes were infected with the highest disease intensity of around 40%. Genotypes showing resistance potential are considered as a potential source of resistance genes that valuable in the disease-resistant soybean breeding