The effects of different explant types and plant growth regulators on the in vitro regeneration of winter rapeseed (Brassica napus L.) varieties

This research was carried out at the Tissue Culture Laboratory of Erzurum Eastern Anatolia Agricultural Research Institute according to the "Split – Split Plot Design in Randomized Blocks" with three replications. Shoot tip, hypocotyl and cotyledon explants of Elvis and Californium canola (Brassica napus L.) genotypes were used in the study. In addition to control media (only 5% sucrose), 6 different plant growth regulators (T1: 3.0 mg L-1 BAP; T2: 1.0 mg L-1 IAA; T3: 1.0 mg L-1 NAA; T4: 2.0 mg L-1 BAP + 1.0 mg L-1 KIN; T5: 2.0 mg L-1 BAP + 0.1 mg L-1 NAA; T6: 2.0 mg L-1 BAP + 0.1 mg L-1 IAA) were added to MS media to culture explants. Explants were incubated under long-day photoperiod conditions (16 h light, 8 h dark) for 6 weeks. At the end of the 6th weeks, following observations were taken: days to the first shoot appearence; plantlet survival rate; the length of shoots, roots and nodes; the number of shoots, roots and nodes; diameter of leaves; fresh and dry weight of plantlets. As a result of the study, it was seen that Elvis genotype had significant better plantlet characteristics compared to Californium cultivar. Shoot tip and hypocotyl explants gave better results compared to cotyledon explants. It is also clear from the results that, the combination of cytokinin + auxin (BAP + NAA and BAP + IAA) was effective on the improvement of shoot and root regeneration. However, application of BAP + KIN and only NAA was also effective on plantlet micropropagation. Although, days to shoot apperance were earlier in Californium (11.21 days) compared to Elvis (12.94 days), Elvis gave the longest shoots (25.04 mm), compared to Californium (18.47 mm). Shoot tips, hypocotyls and cotyledons illustrated 31.13 mm, 21.01 mm and 13.13 mm shoot lengths, respectively. The longest plantlets were determined on BAP + KIN (31.62 mm) and followed by BAP + IAA (20.66 mm). As a result of the study, Elvis cultivar, shoot tip and hypocoty explants with BAP + NAA, BAP + IAA and BAP + KIN media combinations could be advised for better canola micropropagation