Free-living Cucurbita pepo in the United States
Viral Resistance, Gene Flow, and Risk Assessment
A report prepared for: USDA APHIS BBEP Biotechnology Coord
By: Dr. Hugh D. Wilson
- Federal Building, rm. 852A
- 6505 Belcrest Road
- Hyattsville, MD 20782
- Order# 43-6395-3-C4203
- Department of Biology
- Texas A& M University
- College Station, TX 77843
- 28 May 1993
Introduction: This report brings together information relating to free-living gourd populations of the United States, their association with domesticated squash and pumpkin populations growing under cultivation, possible genetic contact between free-living and domesticated populations, and possible consequences if this contact involved a transgenic domesticated line that carries viral resistance.
Specific questions include:
- What is known about the geographic distribution of Cucurbita texana, especially with respect to the areas where cucurbits are cultivated commercially?
Is Cucurbita texana a weed? Is it a common weed or a serious weed in any localities? What weedy properties does it possess?
Is Cucurbita texana difficult to control? How is it controlled?
What is known about the viability, fertility, and ecological fitness of hybrids arising from crosses of Cucurbita texana and Cucurbita pepo? What impacts on Cucurbita texana might be expected from gene flow from commercial plantings of cucurbits?
- How would you design an experiment if you wanted to determine whether virus resistant texana-pepo hybrids were more 'weedy' than the parental species? Would gene copy number, homozygosity, or heterozygosity of the virus resistance gene influence the design or interpretation of results?
The report begins with a review of recent information relating to Cucurbita taxonomy and evolution, agricultural history of the eastern United States, and biological definition of the plants under consideration. This overview of recent research, published either in the past five years or in press, provides a rational foundation and biological context for consideration of the specific questions listed above.
What is Cucurbita texana?