|Abstract or Summary
- In the Willamette Valley of Oregon, a combination of the need for rotational crops and an increased desire for biofuel production created interest in planting Brassica napus (canola). However, questions were raised arisen over the potential damage canola production could have on the preexisting Brassica vegetable seed industry. To address these concerns three studies were conducted to: 1.) Determine the potential of gene flow and hybridization via pollen from Brassica napus to related Brassica vegetable crops; 2.) Evaluate whether transgenes will be detectable in harvested Brassica vegetable seed; 3.) Evaluate the potential for volunteer canola to become a contaminant in the Brassica vegetable seed crops. Crossing experiments were conducted in 2007, 2008, and 2009 using Brassica rapa or Brassica oleracea inbred line receptor plants placed within conventional B. napus fields. Once seed set occurred on the receptor plants, each was harvested individually and the seed germinated in a growth chamber. Flow cytometry, morphological and molecular analyses were performed on the seedlings. Hybridization between B. napus and B. rapa inbreds was 74% in 2007, 89% in 2008, and 15% in 2009. However, no hybridization occurred between B. napus and the B. oleracea inbred lines. Experiments were conducted using transgenic B. napus and the previously mentioned vegetable species, to quantify outcrossing rates in a greenhouse environment. Transgenes were detectable in both germinable and non-germinable seed produced on non-transgenic plants. Following B. napus harvest at the field sites, shattered canola seed was collected from both windrow and non-windrow locations. Approximately 30 days after the shatter samples were taken, canola seedling recruitment counts were made in quadrats placed immediately adjacent to the location of the seed shatter samples. Results of this volunteer assessment indicated differences in seed shatter between fields and windrow vs. non-windrow locations, but seedling recruitment only differed by fields. These studies indicate that canola, if grown in the Willamette Valley, has the potential to hybridize with related Brassica vegetable species grown for seed. However, when managed properly, canola volunteer persistence is unlikely to be an issue within fields in the monocot crop rotations used in the Willamette Valley.