Understanding Phalaenopsis
Flower Color Genetics
Rob Griesbach
Figure 1. A Phalaenopsis bellina cell containing chlorophyll
Figure 2. Two cells showing the effects of an admixture of purple anthocyanin and
within green chloroplasts and anthocyanin within the vacuole. yellow carotenoids leading to red color.
“Genes act in mysterious ways, particular those
with which we are not well acquainted.”
I
- Hugo Freed
n Phalaenopsis, flower color is due to three different
pigments – chlorophyll, flavonoids, and carotenoids
(figure 1). Chlorophyll and carotenoids are both fatsoluble pigments. Green chlorophyll is found within the
cell’s chloroplasts; while, yellow to orange carotenoids are
found in chromoplasts. Flavonoids are water-soluble and
found diffused within the cell’s large central vacuole. The
flavonoids can be artificially subdivided into two groups,
the anthocyanins and the co-pigments. The anthocyanins are red to blue in color; while, the co-pigments are
cream colored (Griesbach, 2005).
By mixing these pigments, different colors can be created. For example, a flower may appear red for several
reasons: 1) the presence of a red anthocyanin and the absence of chlorophyll and carotenoids or 2) the presence
of a purple anthocyanin combined with an orange carotenoid (figure 2). In Phalaenopsis the bars are red due to a
purple anthocyanin and an orange carotenoid. The bars
within the center of Phalaenopsis mariae flowers appear
purple because the accompanying orange carotenoids
are absent (figure 3). Most red Phalaenopsis hybrids are
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Phalaenopsis | Third Quarter | Volume 23 | 2013
the result this ‘admixture’ of orange carotenoids and purple anthocyanins (Griesbach, 1984).
Flavonoids are characterized by their unique 3 ring
chemical skeleton. In nature, the flavonoids are found
with one of more sugars and organic acids attached to
the skeleton. The anthocyanins are the class of flavonoids that have hydroxyl groups (-OH) at the 3, 5 and 7
positions on the skeleton. Specific anthocyanins are dis-
Figure 3. Phalaenopsis mariae ‘Zuma Canyon’ showing the difference in
color of bars due to admixture of carotenoid and anthocyanin pigments.?