Author
Submitted to: HortScience
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/28/2010 Publication Date: 2/9/2011 Citation: Wechter, W.P., Levi, A., Ling, K., Kousik, C.S., Block, C.C. 2011. Identification of resistance to Acidovorax avenae subsp. citrulli among melon (Cucumis spp.) Plant Introductions. HortScience. 46(2):207-212. Interpretive Summary: Bacterial fruit blotch (BFB) is a seed-borne disease that threatens most cucurbit crops. Although, limited resistance to this disease has been found in a small number of Plant Introductions in watermelon, no cantaloupe cultivar is available to growers with any significant level of resistance to this disease. In this study, 332 cantaloupe Plant Introductions from around the world were screened for resistance to BFB using a newly developed seed vacuum- infusion assay. Significant differences in levels of resistance to BFB were observed. The majority of lines were found to be extremely susceptible to the disease. Five Plant Introductions were found to have significantly greater levels of resistance than susceptible control cultivars. These 5 Plant Introductions may serve as potential sources of resistance to BFB in cantaloupe breeding programs. In addition, the novel seed vacuum-infusion assay developed for this test should facilitate the rapid screening of other cucurbit Plant Introductions for resistance to this serious disease. Technical Abstract: Bacterial fruit blotch (BFB) caused by the bacterium Acidovorax avenae subsp. citrulli (Aac) is a seed-borne disease that threatens most cucurbit crops. Although, limited resistance has been found in a small number of Plant Introductions (PI) in watermelon (Citrullus spp.), no significant activity in screening melon (Cucumis spp.) PIs for resistance to this disease has been conducted. In this study, 332 Cucumis spp. PI were screened for resistance to Aac using a newly developed seed vacuum- infusion assay. Significant differences in the reaction of the PI to BFB were observed. The majority of lines were found to be extremely susceptible to the disease. However, several PI with lower levels of resistance were also identified. Variability in the reaction of plants within each PI was also observed. Of the 332 PI tested, 16 were selected for standard spray inoculation tests. PI 353814, PI 381171, PI 536573 and PI 614401 all belonging to C. melo and PI 504558 (C. ficifolius), were found to have significantly greater levels of resistance than susceptible control cultivars or other PIs in two independent spray inoculation tests. These PI may serve as potential sources of resistance to BFB in melon breeding programs. |