CHARACTERIZATION OF A SUNFLOWER (HELIANTHUS-ANNUUS L) MUTANT, DEFICIENT IN CAROTENOID SYNTHESIS AND ABSCISIC-ACID CONTENT, INDUCED BY IN-VITRO TISSUE-CULTURE

Genetic variation induced by tissue culture has been characterized in many species. The present study was conducted to genetically and pheno typically characterize an albino mutant in sunflower induced by in-vit ro culture. A single recessive gene defective in carotenoid biosynthes is eventually leads to a chlorophyll loss due to photobleaching, absen ce of seed dormancy, and a low level of endogenous abscisic acid (ABA) in cotyledons and leaves. Further characterization has shown that the endogenous level of the hormone does not increase after drought stres s and that the mutation prevents anthocyanin synthesis.