Genetic and pathogenic characterization of Rhizoctonia solani AG-4 isolates obtained from common bean


Palacıoğlu G., Cankara B., BAYRAKTAR H., Özer G.

Physiological and Molecular Plant Pathology, vol.131, 2024 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 131
  • Publication Date: 2024
  • Doi Number: 10.1016/j.pmpp.2024.102277
  • Journal Name: Physiological and Molecular Plant Pathology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, BIOSIS, CAB Abstracts, Veterinary Science Database
  • Keywords: Anastomosis groups, Disease reaction, Genetic variation, iPBS retrotransposons, Rhizoctonia solani
  • Ankara University Affiliated: Yes

Abstract

Common bean (Phaseolus vulgaris L.) is the most important grain legume. Crop production of common bean is affected by a number of diseases, such as Rhizoctonia root rot, being detected worldwide. Herein, we aimed to genetically and pathologically characterize Rhizoctonia solani isolates obtained from different provinces in Turkey. Anastomosis groups (AG) and subgroups of isolates were identified based on the sequence analysis of the rDNA-ITS region. The most prevalent subgroup was AG-4 HGIII, according to BLAST analysis and the phylogeny of resultant sequences, followed by AG-4 HGI and AG-4 HGII, respectively. iPBS retrotransposons highly supported the phylogenetic tree and provided a high level of genetic variability among isolates to discriminate AG subgroups. The results indicated that the iPBS DNA marker system based on retrotransposons could be used to discriminate Rhizoctonia isolates relying on AG grouping. The virulence of the pathogen isolates changed from 3.67 to 5 based on the agar-plate assay on the susceptible cv. Gina. The reactions of thirty common bean cultivars were also evaluated against the most aggressive isolate in each subgroup. The reaction assay showed significant differences among both isolates and cultivars; the highest disease severity among cultivars was observed to AG-4 HGI, followed by AG-4 HGIII and AG-4 HGII, respectively. None of the cultivars showed resistance to all AG subgroups. Screening of AGs among the isolates and selecting cultivars are critical to managing Rhizoctonia disease due to the range of host suitability according to AG subgroups.