Effects of genotype and cotyledon section on organogenesis in sunflower

The present study was conducted to identify the organogenetic potential of cotyledon sections from different genotypes of sunflower. Seeds were surface sterilized and germinated on hormone free half strength MS basal medium. Cotyledons from 2-day- old seedling were split in half and cultivated on MS medium supplemented with 4.4 mM BAP and 5.4 mM NAA. The experiment was designed in a randomized complete block with 3 replications. There were differences among the genotypes and cotyledon sections for all studied organogenesis parameters. Inbred line CMS60/52 and proximal explants presented the highest values for the percentage of explants producing shoots, 57.1% and 58.5%, respectively. CMS60/52 proximal explants interactions showed the highest values for average number of shoots per explants plated as well (13.3) as regenerant explant (21.3 shoots) respectively. Shoot organogenesis was optimized on proximal explants.