HortScience (2006) 41, 1027-1028
Jorge Pérez-Arocho and Linda Wessel-Beaver (2006)
Screeing for melonworm resistance in squash and pumpkins
HortScience 41 (4), 1027-1028
Regional Meeting poster
Abstract: Melonworm (Diaphania hyalinata) is one of the most damaging pests of squash and pumpkin (Cucurbita sp.) in tropical/subtropical regions of the Americas. In order to identify sources of resistence to melonworm, we evaluated 345 accessions of C. moschata, including both tropical and temperate types, originating from the Americas, Europe, Asia, and Africa. C. argyrosperma (65 accessions) was also evaluated. Accessions were field tested in five single-plant complete blocks planted over a 9-month period in Isabela, P.R. Each plant was evaluated for foliar damage (0-4 scale) at 3 and 6 weeks. Larval counts were made on a five-leaf sample at 8 weeks. Accessions were classified for degree of leaf mottling and pubescence. Differences among accessions were found for foliar damage and number of larva, but ranking of accessions varied, depending on the criteria used to measure resistance. In order to establish independent culling levels, we considered the lower 30% of accessions for each trait. The upper limit was < 0.42 for foliar damage at 3 weeks, < 0.50 damage at 6 weeks, and < 1.25larva/plant. This led to the selection of 34 resistant accessions. We used a similar technique to identify the most susceptible accessions. The susceptible accessions will be used as a control group when the 34 selections are further evaluated. Within C. moschata, accessions with either green leaves or less pubescence had less leaf damage and fewer larva than accessions with mottled leaves or more pubescence. As a group, C. argryosperma accessions were more susceptible, and nearly all had mottled leaves and little pubescence. Untested accessions with green leaves and/or little pubescence might yield additional sources of resistance to melonworm.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Diaphania hyalinata | Squash/pumpkin (Cucurbita) | Puerto Rico |
