Gene flow from transgenic oilseed Brassica juncea (L.) Czern. into weedy Sinapis arvensis L. (wild mustard)

摘要

Gene flow from acetolactate synthase-resistant (HR) Brassica juncea oilseed canola to related weed, Sinapis arvensis (density 1plant/m(2)) was assessed in a 100m(2) field plot of HR B.juncea. Two HR F-1 hybrids (H1 and H2) were detected among 109951 seedlings screened with imazethapyr (hybridization frequency - 1.8x10(-5)). Hybridity was confirmed using flow cytometry, B.juncea-specific amplified fragment length polymorphisms (AFLPs) markers, genomic in situ hybridization (GISH) and PCR-based detection of B.juncea's HR gene. H1 and H2 had 2n=27 and 2n=45 chromosomes, corresponding 3x (SrAB) and 5x (SrAABB) genomic structures and reduced male fertility, 3.2 and 16.6% pollen viability, respectively. H1 was self-incompatible, whereas H2 set seed when selfed (B.juncea trait). Selfed F-2, F-3 and F-4 plants showed HR trait persistence and vigorous growth and high (80-100%) pollen fertility in 22% and 39% of the F-2 and F-3 plants, respectively. No progeny were obtained from F-1,F- F-2 or F-3 hybridsxS.arvensis backcrosses, suggesting the likelihood of introgression of traits is low to negligible.