UTILITY OF IN-VITRO PROPAGATION FOR FIELD-GROWN BROCCOLI - EFFECT OF GENOTYPE AND GROWING-SEASON

We examined an in vitro culture method for propagating unconditioned, field-grown broccoli (Brassica oleracea L. Botrytis group) from pedunc le explants by testing 20 cultivars in fall and spring. Propagation wa s affected significantly by genotype (cultivar) and season. The percen tage of explants regenerating shoots was significantly higher for cult ivars grown in spring (17% to 100%) than in fall (0% to 66%). Shoot re generation from explants of plants within a cultivar also varied signi ficantly (0% to 100%). Additionally the number of propagules produced per explant was influenced by cultivar and was highly correlated with the percentage of explants regenerating shoots. This method for propag ating field-grown broccoli lines is useful, but its applicability can be limited by genetic and environmental factors.