ACCESSION NO: 9169085
PROJ NO: SC-9502369 AGENCY: CSRS SC.
PROJ TYPE: SPECIAL GRANT
START: 01 AUG 95 TERM: 31 JUL 97 GRANT YR: 1995

INVESTIGATOR: Spira, T. P.; Abbott, A. G.; Rajapakse, S.

PERFORMING INSTITUTION:
BIOLOGICAL SCIENCES
CLEMSON UNIVERSITY
CLEMSON, SOUTH CAROLINA 29634

CONTRACT/GRANT/AGREEMENT NO: 95-33120-1934
GRANT YEAR: 1995

OBJECTIVES: The overall aim of this project is to assess the potential for gene flow via pollen from cultivated strawberry into nearby populations of wild strawberry. We will measure the relative fitness of FI hybrids and non-hybrids in the field and greenhouse and in so doing assess whether fitness differences between hybrid and nonhybrid individuals have the potential to eliminate or at least limit gene flow from the cultivated to the wild strawberry. We will also test for evidence of introgression from the cultivar to the wild species.

APPROACH: The relative fitness of hybrid and nonhybrid wild plants will be assessed by obtaining data on seedling emergence, survivorship, seed production, clonal growth, and the persistence of viable seeds in the soil. To assess introgression, we will utilize RAPD (Random Amplified Polymorphic DNA) markers present in the cultivar that are normally absent from the wild species. The presence of these markers in wild plants will allow us to definitively identify hybrid plants.

PROGRESS: 9501 TO 9512
A potential risk of releasing bioengineered crops into the environment is gene flow via pollen from crops to related wild species. In spite of the importance of mitigating this risk, little is known about the escape and persistence of crop genes in populations of related wild species. The cultivated strawberry (Fragaria x ananassa) and its weedy relative (F. virginiana) represent a particularly suitable system for investigating transgene escape and its potential ecological consequences as the two species are interfertile, their flowering times overlap, and they share common pollinators. Moreover, in the eastern US, F. virginiana frequently occurs near cultivated strawberrry farms. For example, in a survey of strawberry farms in the piedmont of South Carolina, we found that seven of the ten farms examined had nearby populations of F. virginiana. In a preliminary test of potential gene flow, potted plants of F. virginiana were introduced into a strawberry farm in SC. Seeds of these wild plants were collected and examined for evidence of hybrid seed formation using RAPD markers. The results of this study indicate that gene flow had occurred from the cultivar to the wild species. Our current research is examining rates of hybrid seed formation in natural populations of F. virginiana that occur at varying distances from the cultivar.

SUBFILE: CRIS