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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #338479
Title: Emergence and epidemiology of Cucurbit yellow stunting disorder virus in the American desert southwest, and development of host plant resistance in melon

Author
item Wintermantel, William - Bill
item GILBERTSON, ROBERT - University Of California
item NATWICK, ERIC - University Of California - Cooperative Extension Service
item McCreight, James - Jim

Submitted to: Virus Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2017
Publication Date: 6/19/2017
Citation: Wintermantel, W.M., Gilbertson, R.L., Natwick, E.T., McCreight, J.D. 2017. Emergence and epidemiology of Cucurbit yellow stunting disorder virus in the American desert southwest, and development of host plant resistance in melon. Virus Research. doi: 10.1016/j.virusres.2017.06.004.

Interpretive Summary: Cucurbit yellow stunting disorder virus (CYSDV), emerged in the Sonoran Desert region of the southwestern USA in 2006 and has become established. The virus is transmitted in the United States by the form of the sweetpotato whitefly that has been present in the region since the early 1990s. CYSDV results in late-season infection of spring melon crops with limited economic impact; however, all summer and fall cucurbits become infected shortly after emergence due to high whitefly populations and abundant host plants. CYSDV is the most significant virus threat to cucurbit production in the region, and previous studies demonstrated an extensive host range for the virus among crops and weeds prevalent in the region. Cucurbit hosts (melon, watermelon, squash) were found to have the highest concentration (titer) of the virus, were efficient sources for virus acquisition, and showed a positive correlation between titer in source plants and transmission. Non-cucurbit hosts had significantly lower CYSDV titers and varied in their capacity to serve as sources for transmission. Multiple factors influence the efficiency with which a host plant species will be a reservoir for vector transmission of CYSDV to crops. A new source of host plant resistance to the virus was found in 2006 in a melon from India, PI 313970. Field tests for additional sources of the virus done from 2007 through 2012 identified some potential new sources of CYSDV in melon. Host plant resistance to B. tabaci has been identified in melon germplasm resistant to CYSDV and could be an important factor in reducing losses to CYSDV. Resistance to CYSDV is being transferred to US western shipping type cantaloupe and honeydew.

Technical Abstract: Cucurbit yellow stunting disorder virus (CYSDV), emerged in the Sonoran Desert region of the southwestern USA in 2006 and has become established. The virus is transmitted by the MEAM1 cryptic species of Bemisia tabaci, which has been present in the region since the early 1990s. CYSDV results in late-season infection of spring melon crops with limited economic impact; however, all summer and fall cucurbits become infected shortly after emergence due to high B. tabaci populations and abundant host plants. CYSDV is the most significant of the virus threats to cucurbit production in the region, and previous studies demonstrated an extensive host range among crops and weeds prevalent in the region. There was considerable variation in virus accumulation and transmission rate among the host plants evaluated as potential reservoirs. Cucurbit hosts had the highest CYSDV titers, were efficient sources for virus acquisition, and showed a positive correlation between titer in source plants and transmission. Non-cucurbit hosts had significantly lower CYSDV titers and varied in their capacity to serve as sources for transmission. Experiments demonstrated that multiple factors influence the efficiency with which a host plant species will be a reservoir for vector transmission of CYSDV to crops. Melon PI 313970 was identified as a new source of host plant resistance to CYSDV in fall 2006, in addition to TGR 1551 (= PI 482420) and TGR 1937 (= PI 482431). Potential new sources of CYSDV resistance were identified by field screening of ca. 500 melon accessions in naturally-infected field tests from 2007 through 2012 melon. Host plant resistance to B. tabaci has been identified in melon germplasm resistant to CYSDV and could be an important factor in reducing losses to CYSDV. Resistance to CYSDV is being transferred to US western shipping type cantaloupe and honeydew.