Gene transformation potential of commercial canola (<i>Brassica napus</i> L.) cultivars using cotyledon and hypocotyl explants

Abstract

Canola (Brassica napus L.) is one of oil crops cultivated in many areas of Iran. Its molecular breeding and production of varieties with new characteristics using genetic engineering needs the establishment
of efficient transformation methods in commercial varieties. In this research transformation potential of 8 commercial cultivars; Licord, SLM046, RGS003, Zarfam, Okapi, Sarigol, Modena and Opera adapted to different regions of Iran was studied using cotyledon and hypocotyl explants. Agrobacterium tumifaciens strain AGL0 containing the plasmid pCAMBIA3301 was used for transformation. Cotyledon
and hypocotyl explants after inoculation with Agrobacterium were co-cultivated on MS medium containing 1 mg/l 2,4-D and 4.5 mg/l BAP, respectively. Cotyledonary explants after co-cultivation were
transferred on selection MS medium, containing 4.5 mg/l BAP and 3 mg/l phosphinothricin. Hypocotyl explants were transferred to selection MS medium containing 4 mg/l BAP, 2 mg/l Zeatin and 5 mg/l
phosphinotricin. The regenerated plants were analyzed by PCR and histochemical GUS assay for gene transformation. The results showed that all of genotypes had gene transformation potential using
hypocotyl segments, while this potential was limited to some cultivars using cotyledonary explants. Among transgenic plants regenerated from hypocotyls, Licord cultivar had the most transformation rate
(15.26%) and Sarigol the least (0.2%). Also among regenerated plans from cotyledon, SLM046 cultivars had the most transformation frequency (4.7%), and Modena, Opera and Zarfam cultivars did not respond to transformation.