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

Abstract

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.

Identification, Characterization, and Regulation of a Novel Antifungal Chitosanase Gene ( cho ) in Anabaena spp

“…Isolates belonging to two Anabaena species (Anabaena fertilissima RPAN1 and Anabaena sphaerica RPAN12) that have different antifungal activities (31) were used in this investigation; these isolates are part of the germplasm of Anabaena isolates from diverse agro-ecological areas of India (25). The phytopathogenic fungus F. oxysporum, which causes diseases of various crops (tomato, chili, pepper, brinzal, red gram, ginger, linseed, etc.…”

Monitoring the biofertilizing potential and establishment of inoculated cyanobacteria in soil using physiological and molecular markers

“…Smith et al (1998) suggested the utility of highly iterated palindromic sequences (HIP), based assay in distinguishing cyanobacterial species and strains. Earlier studies (Prasanna et al 2006;Sood et al 2008;Nayak et al 2009) also revealed that such molecular polymorphisms can aid in understanding genetic relationships and differentiation of the Anabaena/ Nostoc strains.…”

“…(Singh and Bisoyi 1989;Prasanna and Nayak 2007;Nayak et al 2001Nayak et al , 2004Nayak et al , 2009). Earlier, Kaushik and Prasanna (1995) had demonstrated the existence of competition among the strains used in cyanobacterial biofertilizer consortia with dominance of one or two strains (generally Anabaena or Nostoc sp.)…”

“…Three primer sequences (based on cyanobacteria-specific sequences; Mazel et al 1990;Nayak et al 2009): 5′-3′-short tandemly repetitive repeat (STRR) 1A (CCAATCCCCAATCCCC), STRR mod (GCGCCCCAATCC) and HIP AT (GCGATCGCAT) were employed for PCR amplification (Nayak et al 2009;Prasanna et al 2010b). Primers were synthesized by Bangalore Genei (India).…”

Identification and characterization of endoglucanases for fungicidal activity in Anabaena laxa (Cyanobacteria)

“…The chitosanase homologue responsible for fungicidal activity had been earlier identified in this strain (Prasanna et al 2010a). This strain has been previously identified both morphologically (Nayak et al 2009) as well as on the basis of 16S rDNA (Accession number GQ466518, GQ466546, GQ466574). Firstly, the genomic library for RPAN8 was constructed which generated 2000 clones each having 2-5 kb fragment size.…”