The first report of tomato foot rot caused by Rhizoctonia solani AG-3 PT and AG-2-Nt and its host range and molecular characterization

Abstract

Foot rot of mature tomato plants was found in four cities of Hokkaido, Japan, from 2004 to 2007. Six of eight isolates obtained from damaged tissues were identified as Rhizoctonia solani anastomosis group (AG)-3, and the remaining two isolates belonged to AG-2-1. We compared these isolates with nine reference isolates including the different subgroups in AG-3 (PT, TB and TM) and AG-2-Nt (pathogen of tobacco leaf spot) within AG-2-1 in terms of pathogenicity to tomato, tobacco and potato. All eight isolates caused foot rot on tomato. The six AG-3 isolates caused stem rot on young potato plants. While, all reference isolates of AG-3 PT causing stem rot of young potato plants incited foot rot on tomato. The two AG-2-1 isolates and an AG-2-Nt reference isolate caused severe leaf spot on tobacco leaves. The sequences of rDNA-ITS region and rDNA-IGS1 region of the AG-3 isolates showed high similarity to that of AG-3 PT isolates. Phylogenetic tree based on ITS and IGS1 regions of rDNA indicated that the AG-2-1 isolates from tomato formed a single clade with AG-2-Nt isolates and that they were separate from Japanese AG-2-1 isolates (culture type II). Pathogenicity tests and DNA sequence evaluation of the causal fungi revealed that the present isolates of AG-3 and AG-2-1 belonged to AG-3 PT and AG-2-Nt, respectively. This is the first report of tomato foot rot caused by R. solani in Japan.

Characterization and pathogenicity of Rhizoctonia SPP. isolated from vegetable crops grown in greenhouses in Samsun province, Turkey

“…However, in Turkey, isolates of AG-1, AG-2 type 1, AG-3, AG-4, AG-5, AG-6, AG-9, AG-10 and AG-11 of R. solani and AG-A, AG-E, AG-F, AG-G, AG-I and AG-K of BN Rhizoctonia were previously detected on bean and pepper plants in different regions of Turkey (DEMIRCI;DOKEN, 1995;DEMIRCI, 2004;TUNCER;EKEN, 2013). In addition, Misawa and Kuninaga (2010) identified foot rot caused by R. solani AG-2-1 and AG-3 on mature tomato plants in Hokkaido, Japan. Similarly, other researchers reported that Rhizoctonia group fungi were detected on 264 Characterization and pathogenicity… YILDIRIM,E. ;Ismail ERPER,I. cucumber, eggplant, lettuce, tomato and pepper grown in greenhouses worldwide (MITIDIERI;MITIDIERI, 1994;LEWIS;LUMSDEN, 2001;ERPER et al, 2002).…”

“…were detected on different vegetable crops, including bean, cucumber, eggplant, melon, onion, pepper, pumpkin, tomato, watermelon and winter squash worldwide (SNEH et al, 1991;ERPER et al, 2002;2011;MIRMAJLESSI et al, 2012;MISAWA;KUNINAGA, 2010). Karaca et al (2002) isolated 229 isolates belonging to R. solani AG-2-2, AG-4 and AG-5 from roots and rhizosphere soils of the bean plants in Samsun province.…”

“…R. solani is found on bean, cucumber, eggplant, pepper and tomato, which are important vegetable crops. In addition, R. solani can cause several types of damage, including dampingoff, root rot and web blight on bean (MUYOLO et al, 1993;KARACA et al, 2002;DEMIRCI, 2004;ERPER et al, 2011), damping-off and root rot on cucumber HARATIANA et al, 2013;JAISWAL et al, 2014), brown spot on eggplant (SNEH et al, 1991), damping-off, hypocotyl rot and root rot on pepper (KARACA et al, 2002, VELÁSQUEZ;VICTORIANO, 2007;LOPEZ et al, 2009;TUNCER;EKEN, 2013) and damping-off, foot and root rot on tomato MISAWA;KUNINAGA, 2010;SOLANKI et al, 2012).…”

A Comprehensive Overview on Black Scurf of Potato

“…AG-3 was originally designated as a homogeneous population, causing disease only on potato. Members of this group have since been shown to infect tomato and tobacco (Kodama et al, 1982;Meyer et al, 1990;Misawa & Kuninaga, 2010). Stevens Johnk et al, (1993) differentiated AG-3 isolates from potato and tobacco on the basis of culture appearance, fatty acid profile and pathogenicity.…”

“…Subsequently, AG-3 was divided into three subgroups: AG-3PT (potato type), AG-3TB (tobacco type) and AG-3TM (tomato type), according to the variation in nuclear ribosomal rDNA internal transcribed spacer (ITS) sequences (Kuninaga et al, 2000a;Misawa & Kuninaga, 2010).…”