Genotypic and phenotypic diversity of Anabaena isolates from diverse rice agro-ecologies of India

The genus Anabaena is one of the commonly observed genera in the rice fields in South-east Asia. Diversity analyses of a set of 70 Anabaena strains (including 67 strains isolated from diverse rice agro ecologies of India, and three International Reference/Type strains), was carried out using morphological and molecular datasets. The pattern of growth in liquid and solid medium and microscopic observations revealed tremendous diversity in the Anabaena germplasm analysed. The species wise distribution in different soil types and soil pH revealed that Anabaena iyengarii was present at pH ranging from 5.5-8.5 and all the species of Anabaena except A. oscillarioides were present in alluvium soils. Molecular profiling using primers based on HipTG, STRR(mod) and STRR1A sequences generated specific fingerprints for individual isolates. STRR1A was observed to be the most informative and useful for differentiating the isolates. Analyses of a combined dataset, including both morphological and molecular data, proved highly effective in discerning the genetic relationships among the 70 Anabaena strains. The present study provided useful information for the development of a comprehensive database based on the distribution of Anabaena strains in diverse agro ecologies of India and identified useful primers for PCR based differentiation of isolates.