General microflora, arbuscular mycorrhizal colonization and occurrence of endophytes in the rhizosphere of two age groups of Ginkgo biloba L.of Indian Central Himalaya

Abstract

The populations of the general microfl ora (bacteria, actinomycetes and fungi) in the rhizosphere and their corresponding non-rhizosphere soil samples of Ginkgo biloba L. of two age groups (Group A, <25 years-young trees; Group B, >60 years-old trees) growing under a temperate location of Indian Himalayan Region (IHR) have been determined. Observations were also made for the diversity, distribution and colonization of arbuscular mycorrhizal (AM) fungi and occurrence of endophytes in roots of G. biloba. The population of general microfl ora was found to be higher in the rhizosphere of Group B trees, more clearly refl ected in terms of rhizosphere: soil (R: S) ratios. Contrary to this, per cent colonization and spore densities of AM fungi were higher in the rhizosphere of Group A trees as compared to the rhizosphere of Group B. AM fungal colonization was observed mostly in form of loose coils. All the spores detected, belonged to the genus Glomus with fi ve different types. Presence of endophytes (both bacteria and fungi) was observed in the cortical cells of G. biloba roots, more profound in case of Group B trees. Data suggest that, while the species of Glomus dominated the rhizosphere of G. biloba, an inverse correlation exist between the colonization of general microfl ora and the colonization of AM fungi including endophytes.

Response of Cold-Tolerant Aspergillus spp. to Solubilization of Fe and Al Phosphate in Presence of Different Nutritional Sources

“…Documentation of microbial diversity, including mycorrhizae, in various ecological niches of the Indian Himalayan Region (IHR) with particular reference to biotechnological applications, such as development of microbial inoculants for colder regions, has received attention in recent times [36][37][38][39]. Cold-tolerant bacterial inoculants, possessing plant growth promoting and biocontrol properties, have already been developed in suitable formulations with particular reference to field applications under mountain ecosystems [40][41][42][43][44][45][46].…”

Trichoderma gamsii (NFCCI 2177): A newly isolated endophytic, psychrotolerant, plant growth promoting, and antagonistic fungal strain

“…Research on microbial diversity, with a view of their colonization and applications under temperate locations of Indian Himalayan Region (IHR), has received attention in last two decades . Colonization by endophytic microorganisms and their applications has also got attention . The present study deals with the isolation and characterization of an endophytic fungus from the lateral roots of lentil, a major legume crop grown in IHR.…”

Arbuscular mycorrhizal fungi associated with the rhizosphere of seedlings and mature trees of Swietenia macrophylla (Magnoliophyta: Meliaceae) in Los Tuxtlas, Veracruz, Mexico

“…Kuntse, these authors observed that when the age of seedlings of tropical trees increases the diversity of AMF declines. Similarly, Kumar et al (2009) found higher colonization percentages and densities of AMF spores in young plants compared with old trees of maidenhair (Ginkgo biloba L.). Our results showed the opposite trend, finding more AMF species in the rhizosphere of mature trees than in seedlings, which can be explained by the fact that when trees have been longer periods of time in natural ecosystems, the possibility to be colonized by a more diverse community of AMF propagules can be increased.…”