Effects of three glomus species as biocontrol agents against verticillium-induced wilt in cotton

Abstract

The objective of this investigation was to study the effects of three Glomus species: G. etunicatum, G. intraradices and G. versiforme on the development of verticillium wilt in cotton plants. Results indicated that the influence of arbuscular mycorrhizal fungi as a biocontrol agents were different among three Glomus species. In diseased cotton plants colonized by G. etunicatum, the disease index was lower than others and also, higher colonization percentage was relevant to these plants. On the other hand, the establishment of mycorrhizal symbiosis and development of structure of AMF were reduced when both symbiotic and pathogenic fungi infected the same root. In addition, the symptoms of veticillium wilt were diminished too. These results revealed that the beneficial effects of mycorrhiza could alleviate the pathogenic effects of V. dahliae and also a competitive interaction existed between these pathogenic and symbiont fungi.