Distribution of Arbuscular Mycorrhizae (AM) in some selected soils of Visakhapatnam: A Case study

Abstract

The soil fertility is mainly due to soil microorganism, those also include Mycorrhizae. Arbuscular Mycorrhizal (AM) fungi are soil microorganisms that establish mutual symbiosis with the majority of higher plants, providing a direct physical link between soil and plant roots. For rapid growth of plants in soil as well as sandy zones, beneficially microbe especially AM fungi play an important role. Visakhapatnam is a port city with an area of 200 sq.km. This is emerging as one of the metropolitan cities due to rapid growth in population and industrialization. The purpose of this study was to investigate the potential and distribution of Arbuscular Mycorrhizae in some polluted soils of Visakhapatnam. Results of physico-chemical analysis of soil samples showed that low nutrients status except control soil samples (collected from NPS-1 and NPS-6). The spore density of Glomus morphotypes (r= 0.9295) was significant and strongly correlated and compared with other Arbuscular Mycorrhizae fungi. Scutellospora (r= 0.474) has moderate co-relation in the non-polluted area, where as in polluted study area Glomus morhpotypes (r= 0.96) was significant highly correlated to others, like Scutellospora (r= 0.536) and Acaulospora (r= 0.076) (very low or negligible correlation). In the polluted soils, spores of Glomus microcarpum were frequently found as dead spores in comparison to others. Indigenous AM isolates existing naturally in polluted soils are more tolerant than isolates from non-polluted soils, and are reported to efficiently colonize plant roots in pollution-stressed environments. Thus, it is important to screen indigenous and pollution-tolerant isolates in order to guarantee the effectiveness of AM symbiosis in restoration of contaminated soils.