Identification of Phytophthora capsici causing collar rot in hot peppers in Trinidad

Abstract

Hot pepper (Capsicum chinense Jacq.) is an economically important commercial crop cultivated in Trinidad for domestic consumption and for export in its fresh and processed forms. Collar rot and wilting symptoms have been observed in major hot pepper producing areas of Trinidad over several years, resulting in severe crop losses. Isolations were made from infected plants using corn meal agar (CMA) amended with antibiotics. The isolated organism was identified as Phytophthora capsici based on morphological and microscopic observations. Inoculation of zoospores of P. capsici onto healthy seedlings confirmed the typical expression of symptoms of collar rot and wilting in hot peppers under greenhouse conditions. PCR amplification and nucleotide sequencing of the internal transcribed spacer (ITS) region of rDNA using the primers ITS4 and ITS6 and of the mitochondrial cytochrome c oxidase gene using primers FMPhy-8b and FMPhy-10b confirmed the pathogen as P. capsici. To the best of our knowledge, this is the first report identifying and confirming P. capsici affecting hot peppers in Trinidad.