Translocation and Transfer in Rhizoctonia: Mechanisms and Significance

Abstract

Many important aspects of the biology of Rhizoctonia depend on translocation in the hyphae. For example, R. solani can grow considerable distances through soil by translocating nutrients from a food base. The infection process depends on mobilization of resources to infection cushions or other pre-penetration structures (Dodman, 1970). Nutrient translocation enables Rhizoctonia spp. to serve as mycorrhizal symbionts of orchids. Translocation also mediates the remobilization of mycelial components into developing sclerotia, for survival in soil. In addition, the control of nuclear distribution and migration is central to the population genetics of Rhizoctonia (Vilgalys and Cubeta, 1994). And an understanding of the mobilization and transfer of extrachromosomal genetic elements in Rhizoctonia could have major implications for disease management. The control of some of these processes could be within grasp, because the mycoparasite Verticillium biguttatum can suppress sclerotium production by R. solani AG 3, possibly by altering the normal patterns of translocation (Van den Boogert and Deacon, 1994).