Effect of genotype, explant and plant growth regulators on in-vitro organogenesis of sunflower (Helianthus annuus L.)

In this study in order to achieving high frequency regeneration of sunflower effect of genotype (Record, Progress, Gabor, AF81-196 A line and CMS19 A line), Proximal and Distal section of the cotyledon explant and 10 plant growth regulator combination have been investigated. Seeds without pericarps were surface sterilized and germinated on half strength MS basal medium. Cotyledons from 2-day old seedling were cut from the middle and three explants of each section were transferred to regeneration medium. Regeneration medium consisted of full strength MS medium supplemented with two levels of BAP (1 and 2 mg/l) in combination with three levels of NAA and IAA (0, 0/5 and 1 mg/l). Experiment was conducted in a factorial completely randomized design with three replications. Statistical analysis showed that there were significant differences among the genotypes, explant and plant growth regulator treatments on both organogenesis parameters including regeneration rate and the average number of shoots per explant. Our results showed that the shoot regeneration in sunflower is genotype-dependent, and proximal section of cotyledon explant was greater potential for shooting. CMS19 and Progress were the best responding genotypes with a regeneration rate of 51/21% and 41.21%, respectively. The highest rate of shoot regeneration was observed with 2 mg/l BAP in combination of l mg/l IAA.