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 phenotypically characterize an albino mutant in sunflower induced by in-vitro culture. A single recessive gene defective in carotenoid biosynthesis eventually leads to a chlorophyll loss due to photobleaching, absence 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 stress and that the mutation prevents anthocyanin synthesis.