An update to the canadian range, abundance, and ploidy of camelina spp. (brassicaceae) east of the Rocky Mountains
Martin, S.L., Smith, T.W., James, T., Shalab, F,, Kron, P., and Sauder, C.A. (2016 to be submitted). "An update to the Canadian range, abundance and ploidy of Camelina spp. (Brassicaceae) east of the Rocky Mountains.", Botany.
Résumé en langage clair
Three species from the genus Camelina in the Mustard family have been introduced to Canada and are considered invasive. However, where these plants currently occur is unknown and we need this information for risk assessment work prior to the release of transgenic lines of the emerging oilseed Camelina sativa. We determined where the species occur in Canada east of the Rocky Mountains and investigated reports that Canadian populations of Camelina microcarpa had variation in chromosome number. We found two of the three species still have populations in Canada while the third appears to have been lost. We also determined that there are populations of C. microcarpa with 2n = 26 (tetraploid) and 2n = 40 (hexaploid) within Canada. An evaluation of the material available from genebanks indicated none had the tetraploid, but resulted in the discovery of a diploid with 2n = 12 and in the characterization of chromosome number and DNA content of available species. Given the current geographic ranges, abundance, and chromosome counts of these species, the greatest risk of hybridization with transgenic C. sativa in Canada is from hexaploid C. microcarpa.
The distribution and abundance of three Camelina species introduced to Canada is unknown, but critical for evaluating the risks associated with unconfined release of transgenic Camelina sativa (L.) Crantz (2n = 40). Furthermore, previous reports suggest Canadian populations of Camelina microcarpa Andrz. ex DC. vary for ploidy and ability to hybridize with C. sativa. We completed 8 weeks of field work in Alberta, Saskatchewan, Manitoba, southern Ontario, Quebec, and the Maritimes. We determined the ploidy composition of the populations found. We did not locate Camelina alyssum (Mill.) Thell., but located four sites with C. sativa and 34 with C. microcarpa. Eleven C. microcarpa populations were tetraploid (2n = 26, 1.00pg/2C) and 22 were hexaploid (2n = 40, 1.50pg/2C), while two populations were mixed. We examined material from botanical gardens and plant gene resource centres assessing total nuclear DNA content and completing chromosome counts for each species and cytotype identified, to determine whether tetraploid and hexaploid C. microcarpa were included in these collections. No tetraploid material was included in the C. microcarpa accessions received; however, a diploid (2n = 12, 0.54pg/2C) was found. Given the current geographic ranges, abundance, and chromosome counts of these species, the greatest risk of hybridization with transgenic C. sativa is from hexaploid C. microcarpa.