Abstract Detail

Sexual selection in flowering plants: traits, processes, and estimation

Brunet, Johanne [1].

The impact of pollen competition and female choice on the spread of a genetically engineered cultivar gene in wild squash populations.

Sexual selection, both intrasexual (male-male) competition and inter-sexual selection (female choice) can influence the introduction and spread of genetically engineered (GE) genes from crops into populations of wild relatives. The free-living squash Cucurbita pepo subsp. ovifera var. ozarkana (OZ) is known to grow in proximity to cultivated squash throughout its native range. To recreate the process of the introduction and spread of a GE gene into wild squash populations, we made first-generation hybrid (F1) crosses and first- (BC1) and second-generation (BC2) backcrosses between wild squash and a GE squash (Destiny III). This squash cultivar is resistant to three viral pathogens, zucchini yellow mosaic virus (ZYMV), cucumber mosaic virus (CMV), and watermelon mosaic virus (WMV-2). To examine pollen competition, we provided equal amount of wild and Destiny III (D3) pollen on stigmas of wild squash plants and examined the proportion of GE seeds produced. Because the GE gene provides resistance to ZYMV, we performed the pollen competition experiments under all combinations of diseased or disease-free pollen donor and pollen recipient. We used a generalized linear model (proc Glimmix in SAS v. 9.4) with a binomial distribution and a logit link function to determine whether cross type, health status (diseased or disease-free) of pollen receiver or pollen donor affected the proportion of GE seeds produced. Our results indicate that sexual selection, via pollen competition and female choice, impacts the introduction and spread of the GE gene and its effect is expected to vary with the disease level in wild squash populations.

1 - USDA-ARS VCRU, Dept. Of Entomology, 1630 Linden Drive, University Of Wisconsin, Madison, WI, 53706, United States

Keywords:
Sexual selection
Genetically engineered
Pollen competition
Female Choice
Disease.

Presentation Type: Colloquium Presentations
Session: CO08, Sexual Selection in Flowering Plants: Traits, Processes, and Estimation
Location: Tucson H/Starr Pass
Date: Tuesday, July 30th, 2019
Time: 2:45 PM
Number: CO08006
Abstract ID:734
Candidate for Awards:None