Isolation, characterisation and identification of a potyvirus from Dioscorea alata L. (water yam) in Nigeria

aphis craccivora caupi cowpeas cultivars dioscorea alata electron microscopy elisa enfermedades de las plantas identification igname immunodiagnosis immunodiagnostic maladie des plantes microscopia microscopie microscopy names pathogens plant diseases plant viruses potyvirus test elisa variedades varieties vigna unguiculata virus de las plantas yams