Chimeras in Dahlias – What Are They, and Can You Create a New Variety?

About Chimeras

Chimerism is a common occurrence in dahlias, attributed to their large genome and variability. It is characterized by the presence of two genetically distinct cell types within a single plant. This phenomenon arises from spontaneous mutations and the presence of transposons, or “jumping genes,” in dahlias. These transposons can change positions within the genome, sometimes inserting themselves into gene regions responsible for synthesizing enzymes that catalyze flower pigmentation.

In most cases, variegated plants are chimeras, where two types of cells coexist: those with the standard green chlorophyll pigment and those with a white pigment. Therefore, if you observe white leaves on dahlias or other vegetatively propagated plants, it may not necessarily indicate a viral mosaic.

As mentioned earlier, chimeras result from mutations or “sports.”

Is it possible to develop a new variety from a chimera?

For hobbyists, achieving this from a “half-and-half” or sectorial inflorescence is challenging. One must wait until one of the flower colors “dominates.” After this, a cutting can be taken from the fully mutated part of the plant and rooted. However, even this method doesn’t guarantee a 100% success rate; it’s essential to monitor the stability of the mutation over 1-2 seasons. It’s precisely due to such “sports” that the well-known dahlia ‘Café au Lait’ has many “siblings,” such as ‘Café au Lait Mini’ (or ‘Jolene’), ‘Café de Paris,’ ‘Café au Lait Royal,’ and others.