Molecular Identification of Phytophthora spp. Affecting some Economically Important Crops in Eastern India through ITS-RFLP and Sequencing of the ITS Region

Journal of Phytopathology (Impact Factor: 1). 01/2009; 157:666-674. DOI: 10.1111/j.1439-0434.2008.01537.x

ABSTRACT Molecular identification of the Phytophthora spp. affecting betelvine (Piper betel), brinjal (Solanum melongena), guava (Psidium guajava), roselle (Hibiscus subdariffa), black pepper (Piper nigrum), sesame (Sesamum indicum), taro (Colocasia esculenta), chilli (Capsicum annuum), pointed gourd (Trichosanthes dioica), papaya (Carica papaya) was performed through rDNA ITS-RFLP and also additionally by sequencing the Internal Transcriber spacer (ITS) ITS1 and ITS2 regions. Phytophthora nicotianae, Phytophthora capsici, Phytophthora colocasiae, Phytophthora melonis and Phytophthora palmivora isolates from these 10 different crops were accessioned and the ITS sequences were deposited in Genbank. ITS sequences for Phytophthora isolates from most of these crops are being reported here for the first time. In this study, a review of all earlier Indian reports based on morphology from the above crops and their molecular corroboration has been attempted. This study revealed that not only is P. nicotianae the most prevalent species but also there is the presence of both P. nicotianae and P. capsici, but not P. palmivora on betelvine; as well as possible first reports of P. nicotianae on pepper, P. capsici on chilli and P. palmivora on papaya from this vegetable growing Eastern region of the country. Mating type assays and RAPD markers were used to assess the genotypic diversity of the population. This detection of diversity is a first and critical step for helping to devise and adopt strategies for control and quarantine of these pathogens in this region.

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