ANTHER CULTURE IN HELIANTHUS-ANNUUS L, INFLUENCE OF GENOTYPE AND CULTURE CONDITIONS ON EMBRYO INDUCTION AND PLANT-REGENERATION

Production of microspore- derived embryos from cultured anthers is now a well established technique for the isolation of homozygous lines in many crop plants. We describe here a culture method for embryo induct ion and plant regeneration from anthers of four sunflower genotypes. F or preliminary experiments, anthers of uninucleate microspores were cu ltured on four types of basal media viz., Murashige and Skoog's MS, Ga mborg's B5, Nitsch and Nitsch, and White's W, supplemented with 1.0 mg /l 2,4 dichlorophenoxy acetic acid and 0.5 mg/l 6-benzylaminopurine an d 40 g/l sucrose. MS basal medium, being more responsive for embryo in duction, was used for further experimentation. To optimise the culture requirement MS basal medium was supplemented with 0.2-2.0 mg/l 2,4 di chlorophenoxy acetic acid and 0.5 and 1.0 mg/l 6-benzylaminopurine. Th e effect of cold pretreatment, hormone regime and sucrose concentratio n were tested for embryogenic efficiency. Genotype had a significant e ffect on the capacity of embryo induction. Addition of silver nitrate (2.5 mg/l), an ethylene inhibitor, stimulated embryo germination. Plan tlets were obtained (10-15%) from embryos of only one genotype.