Protocol for broccoli microspore culture

Abstract

Broccoli (Brassica oleracea var. italica) is a vegetable cole crop of considerable interest to breeders and seed companies since its area of production has increased in recent years mainly due to improved nutritional qualities, e.g. anticancer properties. Breeding companies strive more and more to bring F₁ hybrid seeds onto the market. F₁cultivars ensure high uniformity, offer high yields due to heterosis, allow rapid production and selection of desired genotypes and provide protection of plant breeder’s rights and the markets of seed companies. The production of hybrid cultivars requires homozygous parental lines. Inbred lines in broccoli can be produced by recurrent selfing, a procedure that takes time (6 to 7 generations of selfing) and is labour intensive due to sporophitic self-incompatibility. An alternative way to obtain pure inbred lines in one generation is the production of doubled haploid (DH) lines by microspore culture. This protocol can also be applied to other cole crops such as head and tronchuda cabbages using small adaptations.