MOLECULAR CHARACTERIZATION OF ANTAGONISTIC RHIZOBACTERIA ISOLATED FROM CUMINUM CYMINUM L

Abstract

Total ten isolates of F. oxysporum were recovered from root rotted parts of cumin plants collected from the four major cumin producing areas of Rajasthan viz. Ahore, Jalore, Jobner, Jodhpur. Rhizobacteria were also isolated from these Cumin plants and those showing antagonistic properties were selected and screened on the basis of various molecular methods. newlinePreliminary Screening was done based on morphology. Colonies of fungal isolates were observed as woolly to cottony with cream to white aerial mycelium and purple pigment .Maximum rhizobacteria isolates formed opaque, flat, smooth and glossy colony with entire margin. Some of them produced coloured colonies also . newlineResults of pathogenecity tests revealed that all isolates were pathogenic to cumin and produced interveinal yellowing of leaves followed by wilting. F. oxysporum isolates produced chlorate-resistant sectors on media complemented with chlorate.112 nit mutants were generated from 10 isolates of Fusarium oxysporum using PDA with 3% and 5% potassium chlorate.Nit mutants were generated to determine distribution of VCGs and their relation to pathogenecity and geographic origin. Based on pairing, complementary nit mutants of all isolates were grouped into six VCGs in such a way that VCG A has 3 members,VCG B and C have2 members and VCGs D,E,F have single member each. VCG diversity in this study was aprox. 60 % which suggests that fungal isolates showed considerable variations.RAPD analysis was done to study phylogenetic relationship.The total number of bands generated by nine amplifying primers was 65 with an average amplification of 7.20 bands per primer. The Jaccard s pairwise similarity coefficient values ranged from 0.58 (A2 and Jod-1 and J2 and Jod-1) to 0.93 (J-1 and A-2) with an average of 0.711, newline12 newlinefor single primer based RAPD patterns .Data based on RAPD of all ten isolates was used to generate a similarity matrix on simple matching co-efficients .Then a dendrogram was constructed by using this matrix with the help of UPGMA tool of NTSYS.This was done