Arbuscular mycorrhizal fungal status in mangroves of Pichavaram Forest, Tamil Nadu, India

Abstract

The diversity and species distribution of arbuscular mycorrhizal (AM) fungi were analyzed in mangrove patches of the Pichavaram Forest. The AM fungal colonization, spore density, and diversity indices in 18 species of true- and associate-mangrove were investigated. Soil analysis results indicated low levels of available nutrients, especially phosphorus (P), with soil being neutral to slightly alkaline, having high electrical conductivity. Some of the earlier reported non-mycorrhizal plant families also showed AM symbiosis with a high degree of root colonization. All the species at the three sites explored showed significant variation in AM fungal root colonization and spore density. The salt marsh species Salicornia brachiata showed the highest degree of root colonization. Overall 21 AM species belonging to seven genera were recovered from the mangroves of Pichavaram Forest. Statistical analysis showed that relative abundance and isolation frequency of AM fungal species were positively correlated. Among AM fungi, species belonging to the family Glomeraceae were dominant. Our results indicated that AM fungal communities differ with the change in soil conditions within the short distances among the habitats.