Abstract
Studies were conducted to screen saline tolerant arbuscular mycorrhiza (AM) fungi in coastal beaches of Kumta in Karnataka. Twenty five coastal plants were screened. The varied AM percent of colonization was observed. Thirteen plants; members of families Acanthaceae, Asclepiadaceae, Convolvulaceae, Euphorbiaceae, Fabaceae, Graminae, Lamiaceae, Solanaceae and Verbenaceae had highest percent of colonization, 75-100%. Six plants, belonging to families Rubiaceae, Apocynaceae and Malvaceae had 50-74% colonization and two plants belonging to families Rhamnaceae and Fabaceae had 25-49% colonization with AM fungi. Least percent (below 25%) colonization was recorded in family Amaranthaceae, Cyperaceae, Plumbaginaceae and Typhaceae. No correlation between percent of root colonization and spore number among examined plants was observed. Total thirty different VAM spores have been recorded belonging to five Genera Glomus, Gigaspora, Acaulospora, Scutellospora and Sclerocystis. Genus Glomus was most predominated while the genus Sclerocystis was the least. Green house pot experiments were conducted on Solanum nigram. Pots were amended with coastal sand and forest soil in the ratio of 3:1, 2:2 and 1:3. Pots amended with only coastal sand and only forest soil were also maintained. Pots were maintained in triplicate and harvested once in thirty days interval. Plants grown in pots amended with 1:3 (coastal sand : forest soil) exhibited significant increase in plant height, root length, number of leaves, chlorophyll content, biomass production, percent of colonization, spore number-uptake as compared to noninoculated (control) plants. Plants grown in 100% sand with inoculums exhibited moderate growth. The importance of AM fungi in coastal sand dunes (beaches) has been discussed.