ANDROGENESIS IN CAPSICUM-ANNUUM-L - EFFECTS OF CARBOHYDRATE AND CARBON-DIOXIDE ENRICHMENT

A new and simple protocol for androgenesis in bell pepper is described . The initial medium, a modification of Nitsch and Nitsch's H medium, consisted of a two-phase system of semi-solid and liquid medium and co ntained maltose as carbon source. The total number of embryos formed w as greater with maltose at 40 g . L-1, but embryos developed better at 10 to 20 g . L-1. Depending on the genotype, the number of embryos an d plants recovered ranged from 3 to 750 and 0.25 to 8, respectively, p er 100 flowers. Further increases in the number of embryos (up to 3561 per 100 flowers) and plants (up to 23 per 100 flowers) could be attai ned by flushing cultures with air enriched with CO2 at 900 mu L . L-1. The ploidy level and the microspore origin of the recovered plants we re determined by flow cytometry and zymograms for isocitrate dehydroge nase. Nearly 65% of the acclimated plants had undergone spontaneous do ubling of the chromosome number, as confirmed by flow cytometry of lea f nuclei. Isocitrate dehydrogenase zymograms demonstrated that plants originated from microspores and that the two parental alleles were equ ally represented among the haploid and dihaploid plants.