Cultural, Morphological, Pathogenic and Molecular Characterization of Isolates of Fusarium spp.

Abstract

Sugarcane is used for producing white sugar, jaggery (gur) and khandsari, and it is also consumed through chewing and juice extraction for beverages. About 80% of the world’s sugar is produced from sugarcane. The crop is vulnerable to several insect pests and diseases at different stages of growth in tropical and subtropical regions. Conservative estimates indicate that diseases may cause 10–15% losses in total sugarcane production under endemic conditions. Sugarcane wilt, caused by Fusarium sacchari, is a major constraint to cane production and contributes to the deterioration of sugarcane cultivars in India. The present study isolated Fusarium spp. associated with sugarcane wilt and evaluated their cultural, morphological, pathogenic and molecular characteristics. Twenty-four Fusarium isolates were collected from wilt-affected sugarcane plants from different growing areas of NTR and Krishna districts of Andhra Pradesh. Each isolate was characterised on the basis of colony growth, colony colour, pigmentation, mycelial texture and conidial morphology. Pathogenicity was confirmed through reinoculation of sugarcane plants, and virulence variability was assessed. Among the twenty-four inoculated isolates, F12 was identified as the most virulent isolate, whereas the remaining isolates showed varying levels of pathogenicity. Molecular characterisation of virulent isolates was performed through DNA extraction and sequencing using universal ITS primers. The study confirmed the usefulness of integrating cultural, morphological, pathogenicity and molecular approaches for identifying wilt-associated Fusarium isolates in sugarcane.