Horticultura Brasileira (2005) 23, 904-910

Leonardo N. Fonseca, Alice K. Inoue-Nagata, Tatsuya Nagata, Rudra P. Singh and Antonio Carlos de Ávila (2005)
Diferenciação de estirpes de Potato virus Y (PVY) por RT-PCR
[RT-PCR For differentiation of Potato virus Y strains in potato]
Horticultura Brasileira 23 (4), 904-910
Abstract: The Potato virus Y (PVY) has become the major virus problem in seed potato growing areas of Brazil. Only necrotic and ordinary PVY strains were found infecting potatoes in Brazil. This situation drastically changed around 1997 when an epidemic of a PVY necrotic variant causing necrotic rings on the potato tuber surface was observed in the country. This study aimed to test the tuber necrotic strain differentiation method proposed by Weilguny and Singh (1998). Twenty eight PVY isolates originated from infected tubers and leaves from four Brazilian States were analyzed by host reaction after inoculation in tobacco, by ELISA using polyclonal antiserum and by the 3-primer RT-PCR method. The ordinary strain type isolates induced vein clearing and chlorotic pearl spots on Nicotiana tabacum leaves. All 24 remaining isolates inducing vein necrosis in leaves were classified as necrotic strains. All 28 PVY isolates positively reacted to PVY polyclonal antiserum by Elisa. Three RNA extraction methods were compared and the guanidine hydrochloride method was the most efficient and of the lowest cost. One isolate from Santa Catarina State and three from Rio Grande do Sul out of 28 PVY isolates submitted to RT-PCR method were differentiated as PVYº, confirming the biological test. One isolate of PVY^N was detected from Santa Catarina and four from Rio Grande do Sul State. The PVY^NTN was detected in Minas Gerais (six isolates), Santa Catarina (three isolates) and São Paulo (ten isolates). These results confirmed the presence of this new variant, PVY^NTN in the main potato growing areas of Brazil.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
Full text of article
Database assignments for author(s): Tatsuya Nagata, Alice Kazuko Inoue-Nagata, Rudra P. Singh

Research topic(s) for pests/diseases/weeds:
molecular biology - genes
surveys/sampling/distribution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Potato virus Y	Potato (Solanum tuberosum)	Brazil (south)