A transgene locus is required for wavy-patterned flowers of transgenic torenia plants

Modification of flower colour in torenia (Torenia fournieri Lind.) by reint roduction of the chalcone synthase (CHS) or dihydroflavonol-4-reductase gen es has been reported (Aida et al.. 2000. Plant Science 153: 33-42). The typ ical modified phenotype among plants with an introduced antisense gene is a uniformly lighter-coloured corolla. Of the 67 plants in which an antisense CHS gene was introduced, only a single line (411-7) showed a wavy pattern on the flower lip. In flowers of this plant, the inner part of the corolla lip was pigmented more deeply than the outer part in a wavelike pattern-a p attern that does not exist in normal cultivars. The segregation ratio of th e flower colour patterns of the offspring and Southern blot analysis demons trated that one of the two transgene loci detected may cause the wavy pheno type; the other locus is never associated with the wavy phenotype but alone it could produce the typical antisense type pattern. (C) 2001 Annals of Bo tany Company.