T
EMPERATURE
AND
L
IGHT
Various cultural conditions, such as temperature and light, may also affect androgenic response.
Anther cultures are usually incubated at 24 to 25° C. In some species, an initial incubation at a
higher or lower temperature has been beneficial. Haploid plant production was increased in
Brassica
campestris
L. by culturing the anthers at 35° C for 1 to 3 days prior to culture at 25° C (Keller and
Armstrong, 1979). In contrast, androgenesis was promoted in
Cyclamen persicum
Mill. by incubating
cultured anthers at 5° C for the first 2 days of culture (Ishizaka and Uematsu, 1993).
Some species respond best when exposed to alternating periods of light and dark, whereas
continuous light or dark cultural conditions have proven beneficial in other species. Other physical
cultural factors, such as atmospheric conditions in the culture vessel, anther density, and anther
orientation, have been studied and found to affect androgenic response in some species; however,
species have varied greatly in their response to these physical factors.
FACTORS AFFECTING GYNOGENESIS