Evaluation of Cucurbits Resistance to Squash leaf curl Yunnan virus Isolate Thailand PK-2018. Squash leaf curl Yunnan virus

Squash leaf curl virus (SLCV) can causes economic losses both in quality and yield in cucurbits. This virus is widely spread and effectively transmit by whitefly (Bemisia tabaci). Genetic resistance of plant is the most effective method to reduce loss occurred. The aim of this study is to evaluate the resistance in cucurbits to Squash leaf curl Yunnan virus isolate Thailand PK-2018 (SLCuYV-TH-PK-2018) under greenhouse condition. A total of 152 cucurbit accessions including 106 of pumpkin (Cucurbita moschata), 39 of wax gourd (Benincasa hispida), and 7 of ridge gourd (Luffa acutangula) were screened for resistance to SLCuYV-TH-PK-2018. Adult whiteflies were provided a 48 hour acquisition access period (AAP) initially on the symptomatic pumpkin plants then transferred to healthy test seedlings at the first leaf stage and given a 72 hour inoculation access period (IAP). After 4 week post inoculation, the virus was detected in inoculated samples using the enzyme-linked immunosorbent assay (ELISA). Disease rating was based on percentage of infected plants and classified as resistant (R), moderate resistant (MR), susceptible (S) and highly susceptible (HR). Twenty two accession of test plants including three of pumpkin, twelve of wax gourd and seven of ridge gourd were found resistant to SLCuYV-TH-PK-2018. The resistance accession identified in this study may be used to develop cultivar SLCuYV-TH-PK-2018 resistant in breeding program.