Development and Field Evaluation of Multiple Virus-Resistant Bottle Gourd (Lagenaria siceraria).

In an effort to develop bottle gourd (Lagenaria siceraria) as a widely adapted rootstock for watermelon grafting, we sought to identify lines with broad resistance to several cucurbit viruses that are economically important in the United States. Preliminary analysis under greenhouse conditions indicated that the currently available commercial watermelon rootstocks were either highly susceptible or somewhat tolerant to one or more viruses. However, in greenhouse screening, several breeding lines of bottle gourd displayed broad-spectrum resistance to four viruses tested, including Zucchini yellow mosaic virus, Watermelon mosaic virus (WMV), Papaya ringspot virus watermelon strain (PRSV-W), and Squash vein yellowing virus. Resistance to PRSV-W and WMV was confirmed through field trials in two consecutive years at two different locations in South Carolina. Two breeding lines (USVL#1-8 and USVL#5-5) with broad-spectrum virus resistance could be useful materials for watermelon rootstock development.