S01 - Session P5 - Field screening of Cucurbita germplasm for resistance to multiple viruses (Poty and Gemini viruses)

Authors: Supornpun Srimat *, Hyungjun Noh, Narinder Dhillon

Pumpkin ( Cucurbita moschata ) is a commercially and nutritionally important vegetable in the world. Multiple viruses such as Papaya ringspot virus (PRSV), Squash leaf curl China virus (SLCCNV) and Tomato leaf curl New Delhi virus (ToLCNDV) are serious production constraints in the tropics. These poty and gemini viruses are endemic in the pumpkin fields at the Research and Training Station of the World Vegetable Center (WorldVeg), East and Southeast Asia, Kamphaeng Saen, Thailand, where the susceptible reference cultivar exhibits complete susceptibilityduring OctobernApril every year. In this virus hotspot, we evaluated 10 WorldVeg Cucurbita moschata lines (S4 generation) and 30 Cucurbita accessions from the National Agrobiodiversity Center (NAC) of the Rural Development Administration (RDA), Republic of Korea, against multiple viruses. Four WorldVeg C. moschata lines were resistant to multiple viruses, while six pumpkin lines segregated for resistance. Eight C. pepo accessions of NAC were susceptible to multiple viruses, while 22 Cucurbita lines segregated for resistance. Seed was saved from resistant plants after controlled pollinations for evaluation against multiple viruses in subsequent generations. A mixture of SLCCNV, ToLCNDV and PRSV was detected in the susceptible reference variety by PCR and RT-PCR.