Virus Diseases Occurred on Squash in Jeonnam Province

Field disease incidences of squash virus diseases in Jeonnam province were estimated to be 76.1% and of delayed planting on August-September (retarding culture) and on February-March (semi-forcing culture) on glass house were 55.0% and 0%, respectively, in 2000. Disease incidences of individual squash plant within a field were 100% and 3.6%, respectively, in wild culture and retarding culture. Total of 61 samples suspected to be infected with viruses were collected in 2000 and tested by RT-PCR using specific oligonulceotide primer sets designed for the detection of Cucumber green mottle mosaic virus (CGMMV), Kyuri green mottle mosaic virus (KGMMV), Zucchini yellow mosaic virus (ZYMV), Papaya ring spot virus (PRSV), Watermelon mosaic virus (WMV), and Cucumber mosaic virus (CMV). Each specific primer set for WMV, ZYMV, and PRSV amplified expected size of DNA fragments from 16, 10, and 2 samples in wild culture, respectively. Double or triple infection were observed in 7 samples tested. In contrast, each specific primer set for WMV, ZYMV, and PRSV confirmed virus infection from 7, 6, and 6 samples, respectively, in samples collected from semi-forcing culture. Double infection of WMV and PRSV was observed in only one sample. However, no DNA fragment was amplified from RT-PCR using CGMMV, KGMMV, and CMV specific oligonucleotide primer sets indicating no CGMMV, KGMMV, or CMV infection in squash fields in Jeonnam province in 2000.