There are several techniques for doubling
the chromosome number of the haploid plants
Regeneration by tissue culture methods: older leaves
have the potential to regenerate both haploid and diploid plants, diploids
result from chromosome endoreduplication, which frequently occurs in cultured
plant tissues.
Chemically induced doubling with colchicine
Chromosome number can be doubled by the application of colchicine to either
the embryos or the haploid plants. (immerse the anthers containing the
newly formed plantlets in an aqueous solution of colchicine (0.5%) for
24-48 hr) or apply colchicine in lanolin paste (0.4%) to the axillary buds.
Alternatives for colchicine are the herbicides oryzaline or amiprophos-methyl.
