Genetic control of in vitro-organogenesis in recombinant inbred lines of sunflower (Helianthus annuus L.)

Ninety-three recombinant inbred lines (F-8) of sunflower developed by the s ingle-seed descent method from the cross 'PAC-2 x RHA-266' were used to scr een their regenerability by organogenesis. The experiment was designed in r andomized complete blocks with three replications. Each replication consist ed of 10 Petri dishes with four explants. Cotyledons were excised from 2-da y-old seedlings. Each cotyledon was divided into two pieces (four explants) , which were incubated in solid regeneration medium consisting of full-stre ngth Murashige and Skoog medium modified by adding hormones. A high genotyp ic variability for organogenesis parameters between genotypes was observed in this study. The difference between all recombinant F-8 lines and their p arents was not significant, showing that the 93 inbred lines used in this e xperiment are representative of the total possible recombinant lines from t he cross 'PAC-2 x RHA-266'. These F-8 lines were not consciously selected f or any trait; therefore, they represent a random set of lines segregating f or the organogenesis parameters, as well as for other traits which could be important for breeding.