The cultural and morphological variability among Rhizoctonia solani isolates causing banded leaf and sheath blight of maize in Indonesia

Abstract

Banded leaf and sheath blight caused by Rhizoctonia solani Kuhn has become a constraint on maize production in Indonesia. Forty-one isolates from 11 provinces in Indonesia were characterized based on cultural and morphological characteristics. Most isolates were characterized with sparse fluffy hyphae and pale yellow mycelium. They were categorized into two, three and four groups based on hyphal width, their growth rate and sclerotia production, respectively. The number of sclerotia was highly variable across different isolates. They were arranged in subcentral-peripheral, irregular, scattered, and peripheral manner on the Petri dish. The UPGMA analysis showed four major clusters, designated as cluster I, II, III, and IV at 0.75 similarity coefficient according to cultural and morphological characters. Cluster III was the largest cluster comprising 34 isolates; while cluster I, II, and IV comprised of four, one, and two isolate, respectively. Our results indicated that the cultural and morphological variability among R. solani isolates in Indonesia was not related to geographic origins.