Phenotypic Reaction of Cultivated and Wild Brinjal Genotypes to Fusarium Wilt Under Sick Plot and Artificially Inoculated Pot Conditions

Abstract

Brinjal (Solanum melongena L.), an important solanaceous vegetable valued for its rich nutritional profile and potential health benefits, is widely cultivated in the tropical and subtropical regions of the world. Existing food and nutritional security concerns are exacerbated due to the rise in soil borne pathogens, a direct consequence of global warming, increasing the risk of crop diseases. Among these, Fusarium wilt, caused by multiple species of Fusarium, is very serious due to its severity and persistent nature. Traditional control measures, including cultural, biological and chemical approaches, have proven inadequate, highlighting the need for resistant cultivars. The current study focused on identifying fungal pathogen associated with brinjal wilt, by employing morpho-cultural identification, molecular characterisation by sequencing and DNA barcoding of internal transcribed spacer (ITS) and β-tubulin regions and pathogenicity assays of fungal isolate. Fusarium oxysporum f. sp. melongenae was identified as the pathogen associated with vascular wilt of brinjal. The study evaluated 90 diverse genotypes, including released varieties and local landraces of cultivated brinjal, and related wild Solanum sp. for resistance against Fusarium wilt by screening under field conditions. Confirmatory evaluation of disease reaction was done by screening under artificially inoculated conditions in pots. Percent disease incidence (PDI), area under disease progress curve (AUDPC) and area under disease progress stairs (AUDPS) were used to identify sources of resistance and understand disease progression patterns. Three genotypes namely Swarna Mani, S. sisymbriifolium and S. torvum were identified as highly resistant and seven genotypes namely G-17, Pink, CH-151, Sidhasar Local, Special Muktakeshi, H-183 and Pink Shiny Medium Long were found resistant to the disease under both field and pot conditions. Resistant genotypes exhibited distinct variations in disease progression patterns. The identified highly resistant and resistant genotypes hold significant potential for breeding programs aimed at enhancing crop resilience to the increasing threat posed by Fusarium species.