HANDLING
OF
HAPLOID
PLANTLETS
For species undergoing direct androgenesis, small plantlets can usually be seen emerging from the
anthers 4 to 8 weeks after culture (Figure 17.2). When these get large enough to handle, they should
be teased apart using fine-pointed forceps and then either placed on a rooting medium (usually low
salt, with a small amount of auxin) or transplanted directly into a small pot filled with soilless
potting mixture. The callus produced in species that undergo indirect androgenesis must be removed
from the anther and placed onto a regeneration medium containing the appropriate ratio of cytokinin
to auxin.
To produce dihaploid plants, it is necessary to double the chromosome number of the haploids,
and for many species, a colchicine treatment is used. Published procedures for producing polyploids
from diploids can be modified for use with anther culture derived haploids. For example, it may