Embryogenesis and plant regeneration in <i>Brassica napus</i> anther cultures

Abstract

Anthers of two cultivars of Brassica napus were cultured on a medium previously used for B. campestris but modified with the addition of 100 mg/ℓ L-serine. The frequency of embryogenic anthers obtained was about 1%. Transfer of anthers from a 10% to a 2% sucrose level after 1- and 2-week culture periods failed to increase the number of embryos obtained and did not result in the production of embryos capable of direct development into plantlets. Although most embryos obtained in this study lacked the ability to develop a shoot system, plants were recovered by inducing shoot formation on hypocotyl expiants cultured on a cytokinin-containing medium.A total of 31 plants were regenerated, 9 of which were examined cytologically and found to be diploid. triploid, or tetraploid. Evidence for the microspore origin of the plants was accumulated and possible mechanisms of diploidization and polyploidization were considered.