Arbuscular Mycorrhizal and Dark Septate Endophyte Fungal Associations in Two Dominant Ginger Species of Northeast India

Abstract

Studies on the prevalence of arbuscular mycorrhizal fungi (AMF) and dark septate endophytic fungi (DSEF) are limited for rhizomatous crops in subtropical ecosystems compared to other terrestrial habitats. Hence, the authors assessed the incidence of AMF and DSEF in roots and diversity of AMF in the rhizosphere of Zingiber montanum and Z. officinale collected from shifting cultivation fields of Manipur, Northeast (NE) India. Both the gingers had dual colonization of AMF and DSEF structures in different cortical cells of the same examined root segments and revealed the Intermediate type of AM morphology. Such endomycorrhizal symbiotic association is being reported for the first time in Z. montanum. Distribution of different AMF and DSEF structures varied significantly across the two ginger species. The total root length colonization with AMF and DSEF was highest in Z. montanum. The maximum spore population of AMF was recorded in Z. officinale soil, whereas the AMF species richness was highest in Z. montanum rhizosphere. Altogether, 13 spore morphotypes of AMF corresponding to eight genera, i.e., Acaulospora, Claroideoglomus, Funneliformis, Glomus, Rhizophagus, Sclerocystis, Scutellospora and Septoglomus were isolated from the field and trap culture soils of both ginger species. Significant positive correlations were recorded between some soil properties and root-colonizing variables of AMF and DSEF. Thus, the occurrence of native AMF and DSEF associations in two important indigenous gingers cultivated in the Jhum fields of hilly terrains reveals the possibility of utilizing them in the future for sustainable agriculture.