IMPROVED TECHNIQUES FOR HAPLOID PRODUCTION IN WHEAT USING CHROMOSOME ELIMINATION

Wheat x maize and wheat x pearl miller crosses have proved efficient f or haploid production using various genotypes of wheat; 22 and 27 % of florets produced embryos. In favourable conditions 6-9 haploid plants per spike were produced. The following simplifications or improvement s in technique are recommended: 1. Only a single treatment with an aqu eous solution of dicamba or 2,4-D (50-100 ppm) for embryo stimulation in vivo; 2. Application by spraying or dipping the spikes; 3. Applicat ion time two to four days after pollination; 4. Embryo rescue 15 to 18 days after pollination; 5. Crosses without emasculation are possible if pollination occurs 1-2 days before anthesis. More than 450 haploids and some doubled haploid (DH) lines (after colchicine treatment in vi tro) were produced using these methods. No hybrid plants, chromosome a dditions or substitutions were found.