Genetic diversity analysis and metabolite profiling of pharmaceutical value Indigenous rice varieties of Tamil Nadu (Oryza sativa Linn.)

Evaluation of local indigenous medicinal rice (Oryza sativa Linn.) varieties using molecular and metabolic profiling plays dynamic role for unravelling the genetic variability and restorative bio actives. In the present study, 18 screened random decamer (RAPD) markers were used to analyze genetic diversity and relationship among 25 indigenous landraces and 1 commercial rice varieties (White ponni), and GC-MS profiling of phylogenetic clusters positioned 4 random indigenous rice varieties and 1 White ponni rice were documented for exploring bioactive metabolites. Random amplified polymorphic DNA (RAPD) analysis of twenty-six rice varieties of Tamil Nadu divulges significant genetic differentiation. The primers produced total of 92 bands with size ranges from 100-8500bp out of 74 were polymorphic bands indicating 80% polymorphism. The mean values of RAPD for polymorphism information content (PIC) of 0.268, effective multiple ratio (EMR) of 23.38, marker index (MI) of 7.39 and the resolving power (Rp) of 4.34. The primer OPA-02, OPD-08, OPF-13 produced maximum number of bands (8), OPAA-07 produced minimum number of band (2). The UPGMA dendrogram were constructed based on Jaccard’s similarity coefficients. The dendrogram resolved the indigenous rice varieties into 3 main clusters and 3 monoclades ranged from 0.467 to 0.860, commercial rice variety shows marginal ungrouped position of 1. In the 3-main clustering, based GC-MS profilling (methanol and acetone rice bran extracts) of Karuppu Kavuni, Karuthakar, Kottara samba, Kaivara samba and ungrouped position of White ponni revealed 88 distinctive bioactive metabolites. And profiling results substantiate that the traditional rice varieties hold promising therapeutic metabolites for sedentary lifestyle disorders.

Seed Borne Endophytic Fungi Associated with Some Indigenous Rice Varieties of North East India and Their Growth Promotion and Antifungal Potential

Background: Seed borne endophytic fungi play an important role in seed germination and plant health. There are ubiquitous and have been found associated in every plant species investigated so far. They colonize plant seeds without causing any disease and are often vertically transmitted. Despite their occurrence, seed borne endophytic fungi are poorly investigated and their role for application in agriculture is still to be elucidated. Methods: In the present study endophytic fungi associated with seeds of some indigenous rice varieties of North East, India was investigated. The isolates were determined for IAA activity in-vitro and antifungal activity against rice pathogen, Magnaporthe grisea. Crude metabolites obtained from potent isolates were characterized by GCMS analysis to reveal the presence of bioactive compounds. Result: Our result indicated that commonly isolated fungal genera were Aspergillus, Fusarium, Gliocladium, Mucor, Penicillium, Bipolaris, Basidiobolus and Mycelia sterilia. Amongst them, colonization frequency (CF %) of Fusarium (8.8%) was found to be highest and was isolated from seeds of almost all the varieties. It was observed that four isolates of Fusarium showed good IAA production in the medium amended with tryptophan. The isolates also displayed antifungal activity against Magnaporthe grisea. GCMS analysis of the metabolites indicated presence of several bioactive compounds. The study suggests that seed borne endophytes can be explored as bio-inoculants for crop improvement in future research program.