Leaf colour patterns, vegetative and sexual reproduction of Episcia ...

darker morphs. The results can, however, not be interpreted insofar as that the varied morphs are
some kind of adaption for different light conditions. Thereto the focus of this investigation was
not enough directed towards the differences among the varied morphs. These experiments can
only be regarded as preliminary investigation. While gathering the presented data, the way of
proceeding seemed adequate. Unfortunately, the intervals of light energy measurements were set
too coarse-meshed. The sun irradiation on a plant has to be measured continuously over the
course of several days to ascertain the duration and incidence of sun spots. Only by that, the
theory of Lee (2002) and Gould et al (1995) concerning the protective function of the
anthocyanins against short-term heightened sun irradiation can be assessed. Special attention on
the different morphs must be paid in this process.
Colour Change in Correlation with Change in Habitats
The influence of UV-radiation on the leaf colouration is known and was already subject of
many investigations (Brandt et al. 1995, Mancinelli 1985, Wellmann et al. 1991). Hoffman (1999)
detected changes in leaf and flower colouration of different species caused by UV-radiation. On
the contrary, she did not found any shifts in colour, when the UV-wavelengths of the incoming
light were blocked.
The enhancement of anthocyanins within a leaf as a protective mechanism was already often
observed and investigated (Bormann and Teramura 1993, Teramura 1983, Tevini and Teramura
1989, Wellmann et al. 1991). The following experiment was conducted to clarify how Episcia
lilacina answers to enhanced solar radiation. For Episcia lilacina grows mainly on the shady forest
ground, the plant is not used to prolonged sunny periods. What happens if the plants of Episcia
lilacina were transplanted to a sunnier location? Do they answer to an enhanced sun exposure?
Do plants with dark red leaves differ in their reaction from plants with bright green leaves?
Materials and Methods: Plants with bright green leaves and without visible anthocyanin
concentration as well as plants with dark red leaves and intermediate stages were selected. A
sunny and a shady place were chosen to conduct this experiment. Before starting, all plants were
photographed to enable a comparison of the leaf colouration afterwards. For the shady location
seven plants were transferred from the rain forest to the main building of the biological station
La Gamba. There, a maximum of 6 Lux of light intensity could be measured. The same was done
with the plants, which were transferred to a sunny location. The search for a suitable sunny
location turned out to be difficult. At first all plants were transplanted in a plastic bag (as a plant
pot) and placed near the main building on a lawn, where the sun was shining almost all day long.
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