ISSN: 0041-3216

ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 81 Number 4
Research Papers
Differential response of papaya cultivars to Papaya ringspot virus isolates from Jamaica. (223)
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Diverse papaya (Carica papaya L.) germplasm were assessed for tolerance by mechanical challenge with Jamaican Papaya ringspot virus type p (PRSV) isolates. One local accession of the large papaya fruit type was found to be tolerant to infections, with plants exhibiting mild symptoms and a recovery phenotype that was dependent on the challenge virus. However, virus was detected by enzyme-linked immunosorbent assay (ELISA) in the recovered plants. Another local accession, C. jamaicensis Urb., was susceptible to all challenge isolates. Furthermore, molecular analyses suggested that C. jamaicensis was more closely related to commercial papaya varieties than to highland species. Other C. papaya cultivars from India, Taiwan, Thailand, and Florida, U.S.A., showed a range in reactions to the Jamaican PRSV isolates. The reactions included no visible symptoms but detectable virus titres, recovery from systemic infections, and attenuated symptom expression as well as susceptibility. Together, the data provide a basis for developing germplasm with natural tolerance to PRSV in Jamaica.
Keywords: Papaya ringspot virus; Papaya; Tolerance; Jamaica