Arbuscular Mycorrhizal (AM) fungal diversity of degraded iron ore mine wastelands of Goa

Abstract

Arbuscular mycorrhizal (AM) colonization and spore count was assessed in 50 plants species from Codli iron ore mine site. Most of the plant species assessed had low to high level of colonization and spore density. Mycorrhizal colonization in herbs ranged from 8 percent in Biophytum sensitivum to 99 percent in Cassia tora. Average root colonization in herbs, shrubs and trees was 50.25 percent, 50.25 percent and 47.43 percent respectively. Spore density exhibited great variations among various plant species ranging from 9 spores 100g sup(-1) rhizosphere soil in Canscora diffusa to 396 spores 100g sup(-1) rhizosphere soil in Vernonia cinerea. Average spore density recorded was higher in shrubs (122 spores 100g sup(-1) soil) followed by herbs (102.5 spores 100g sup(-1) soil) and was least in trees (98.87 spores 100g sup(-1) soil). Arbuscular mycorrhizal fungal spore numbers were related to colonization (r=0.534; P less than 0.01). A total of 40 AM fungal species belonging to four genera viz., Acaulospora, Gigaspora, Glomus and Scutellospora were isolated during the study. Glomus was the most dominating genus followed by Scutellospora, Acaulospora, and Gigaspora. In the present investigation, spores of Glomus microaggregatum Koske & Gemma inhabited the spores of Glomus macrocarpum Tul. & Tul. and, spores and sporocarps of Glomus sinuosum with numbers varying from 1 to 10. The inhabited spores were found to be fresh, while the occupied spores were old and devoid of spore contents.