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United States Department of Agriculture

Agricultural Research Service

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Research Project: Screening of Capsicum Baccatum Accessions for Resistance to Cotton and Green Peach Aphids and Leafminers in South Texas

Location: Plant Genetic Resources Conservation Unit

Project Number: 6607-21000-011-08
Project Type: Specific Cooperative Agreement

Start Date: Sep 01, 2013
End Date: Sep 30, 2014

Objective:
Identify and confirm new sources of resistance to cotton and green peach aphids (Aphis gossypii and Myzus persicae) and leafminers (Liriomyza spp.) in Capsicum baccatum and evaluate potential for introgression of identified resistance into C. annuum.

Approach:
Approximately three-hundred (USDA) genebank accessions of Capsicum baccatum will be grown in the field and exposed to existing natural populations of aphids and leafminers. Data will be collected every two weeks. A minimum of 20 leaves will be examined to the presence of, and damage caused by, cotton aphids and leafminers. Numbers of insects present (dead and alive) on each line/accession will be determined. All data will be subjected to ANOVA and means separated using standard statistical methods. Up to 30 of the most highly resistant lines, as determined in the previously described field screening, will be grown in the greenhouse and exposed to both the green peach and cotton aphids using infested host plants or by manually placing insects on the plants. Aphid mortality and reproduction will be monitored at 2 day intervals for a period of 4 weeks. Leaf damage ratings will be assigned. Data will also be recorded on plant height for comparison with non-infested lines. Data will be subjected to ANOVA. These 30 lines will also be grown in cages (Spring 2014) with infested host plants and rated at weekly for the presence of aphids and leafminers. Selections from the previous 30 accessions that exhibit resistance will be used as sources of pollen in controlled pollinations with Capsicum annuum of various commercial types. Seed produced as a result of these pollinations will be saved for future genetic studies.

Last Modified: 9/1/2014
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