Histogenetic variation in flowers of <em>Angelonia</em> Humb. et Bonpl.


  • S. Plaschil
  • K. Olbricht


Angelonia, a genus of the family Scrophulariaceae, provides new flowering pot plants. The flower colour of Angelonia hybrids ranges from blue to violet, white and pink. Bicoloured Angelonia hybrids are grown in horticultural production.
Here, the reasons for bicolourness in Angelonia flowers are discussed. It was found that the flower colour patterns of bicoloured Angelonia hybrids are chimeral patterns as a consequence of histogenetic variation. This result was proven by light microscopy, double marking of tissues and ploidy analysis as well as somatic and generative segregation. Furthermore, the constitution of periclinal chimeras of bicoloured Angelonia hybrids was verified. Three new bicoloured Angelonia types including two cytochimeras resulted from colchicine treatment of axillary buds. These new types were histogenetically analysed. Thus, the first demonstration of a complete system of ploidy marked histogenetic variation in flower colour patterns is given.