Population Genetics and Anastomosis Group’s Geographical Distribution of Rhizoctonia solani Associated with Soybean

Abstract

Rhizoctonia solani is a species complex composed of many genetically diverse anastomosis groups (AG) and their subgroups. It causes economically important diseases of soybean worldwide. However, the global genetic diversity and distribution of R. solani AG associated with soybean are unknown to date. In this study, the global genetic diversity and distribution of AG associated with soybean were investigated based on rDNA-ITS sequences deposited in GenBank and published literature. The most prevalent AG, was AG-1 (40%), followed by AG-2 (19.13%), AG-4 (11.30%), AG-7 (10.43%), AG-11 (8.70%), AG-3 (5.22%) and AG-5 (3.48%). Most of the AG were reported from the USA and Brazil. Sequence analysis of internal transcribed spacers of ribosomal DNA separated AG associated with soybean into two distinct clades. Clade I corresponded to distinct subclades containing AG-2, AG-3, AG-5, AG-7 and AG-11. Clade II corresponded to subclades of AG-1 subgroups. Furthermore, AG and/or AG subgroups were in close proximity without corresponding to their geographical origin. Moreover, AG or AG subgroups within clade or subclades shared higher percentages of sequence similarities. The principal coordinate analysis also supported the phylogenetic and genetic diversity analyses. In conclusion, AG-1, AG-2, and AG-4 were the most prevalent AG in soybean. The clade or subclades corresponded to AG or AG subgroups and did not correspond to the AG’s geographical origin. The information on global genetic diversity and distribution will be helpful if novel management measures are to be developed against soybean diseases caused by R. solani.

Unveiling the Genetic Tapestry: Exploring Rhizoctonia solani AG-3 Anastomosis Groups in Potato Crops across Borders

“…R. solani isolates were gathered from various potato-growing zones in Pakistan, revealing that the occurrence percentages of AG3, AG5, and AG4 were 81.89%, 8.66%, and 5.51%, respectively. These findings underscored the predominance of AG3 compared to other groups [42]. Initially, AG-3 was classified as a single disease population exclusively affecting potatoes, yet AG-3 has now been shown to infect aubergines, tomatoes, and tobacco as well [54].…”

“…As a result, AG diversity, frequency, and distribution may be influenced by host–pathogen association conditions, genetic versatility, and level of adaptation [ 32 ]. Host–pathogen associations, genetic versatility, and level of adaptation may influence the diversity, frequency, and distribution of anastomosis groups (AGs), whereas root-associated microbial populations have been shown to regulate the dispersion of AGs [ 42 ].…”

Leguminous Seedborne Pathogens: Seed Health and Sustainable Crop Management

“…The disease cycle terminates when the sclerotia, stored in the infected seeds or in plant wastes, return to the soil, where they survive for a long time [ 77 ]. Interestingly, R. solani has been described as a complex, and as a result, it has been divided into 15 somatic-incompatible groups, also known as anastomosis groups (AGs), taking into account hyphal fusion, morphological diversity, differences in biochemical and molecular markers, and diverse pathogenicity and aggressiveness [ 72 , 76 , 78 , 79 ]. Therefore, AGs are differentially represented on the global scale: indeed, AG1, AG2, AG3, and AG4 are the most widespread, while others are specific to certain regions (AG-5 has been found in Canada, Germany, Israel, and Japan; AG-7 has been found in Japan; AG-8 has been found in Australia; AG-9 has been found in America and Canada; and AG-BI has been found in Japan).…”