Diversity of Arbuscular Mycorrhizal Fungi in Different Salinity of Mangrove Ecosystem of Odisha, India

Abstract

A study was carried out to assess the species diversity of arbuscular mycorrhizal (AM) fungi in different salinity zones of Bhitarkanika mangroves of Orissa, India. Sixteen sites of Bhitarkanika mangrove areas were surveyed for the collection of roots and soil samples. Seedlings of mangrove species were tested for AM colonization through root clearing and staining technique. Soil samples were treated separately for the mineral analysis through wet oxidation techniques and spore multiplication by pot culture methods. Wet sieving and decantation technique was followed for the isolation of AM spores from soil. AM spores were identified on the basis of morphological characteristics by following the INVAM manual. The physio-chemical analysis of soil indicated its deficiency in phosphorus which decreases (9.47Kg/ha) with increase in salinity. The genus Glomus is most dominant and has presence across all saline zones. A total of 45 AM species belonging to five genera namely, Glomus, Acaulospora, Gigaspora, Scutellospora and Enterophospora were recorded from three salinity zones of Bhitarkanika mangrove ecosystem. The soils of lower salinity contained maximum number of AM species (21nos.) than the high salinity zones (9 nos.). The decreased number of AM species in high salinity may be due to low phosphorus content and lack of suitable host plant also. Among eighteen mangrove species from different salinity zones analyzed for mycorrhizal colonization in their root system, Sonneratia apetala, Heritiera fomes, Excoecaria agallocha, Derris heterophylla, Bruguiera gynmorrhiza, Avicennia officinalis, Aglaia cucullata, and Aegiceras corniculatum were found to be mycorrhizal. This is first report on diversity of AM species in different salinity zones of Bhitarkanika mangroves of Orissa, India.