Assessment of Sugarcane Genotypes for Red Rot Resistance and Antifungal Activity of Rhizosphere Microbiota against Colletotricum falcatum

Abstract

The aim of this study was to screen the potential of locally grown sugarcane genotypes for red rot resistance and activity of native microbial strains against the pathogen. Field trials were conducted with 70 genotypes for consecutive years and results showed that only two genotypes viz., SSRI-1 and CO-0238 showed resistant behavior towards red rot of sugarcane. The red rot pathogen Colletotrichum falcatum Went was characterized and pathogenicity tests on two susceptible genotypes (NSG-59 and CPSG-2923) showed high virulence of SUCF04 isolate to develop severe disease lesions. The native rhizospheric microbiota was screened for microbial consortia exhibiting fine antifungal activity against the highly virulent pathogenic strain. The antagonism assay exposed that 10 bacterial isolates out of 46 showed great potential for antifungal activity. The selected bacterial isolates revealed 68–99% pathogen inhibition during the assay. The fungal strains with biological control potential inhibited the pathogen growth by 20–80% and a group of three strains with more than 50% antifungal activity were characterized. The molecular characterization of these microbes revealed that the isolates were belonging to Bacillus subtilus, Pseudomonas putida, Pseudomonas fluorescence, Trichoderma harzianum and several other important taxa. This study revealed that only two sugarcane genotypes were found as resistant against red rot pathogen, while most of the genotypes showed susceptible to moderately susceptible response. Moreover, the native residential microbiota associated with sugarcane exhibited great antifungal potential and can be utilized for disease protection and improved crop productivity. © 2021 Friends Science Publishers