Production of doubled haploid plants from anther cultures of borage (Borago officinalis L.) by the application of chemical and physical stress

Anther culture can be used as a powerful tool to produce doubled haploid (DH) lines in medicinal plants, thus accelerating breeding programs. In the particular case of borage (Borago officinalis L.), a method to produce DH plants has not been yet published. In this work we evaluated the effect of different culture media and of different chemical (colchicine and n-butanol) and physical stresses (centrifugation and electroporation) on androgenesis induction and plant regeneration in borage anther cultures. We found that the highest response can be obtained with culture medium containing B-5 salts and NLN vitamins, the addition of 200 mg/l colchicine during 4 days, a pretreatment of anthers with 0.2% n-butanol for 5 h, or the application to anthers of single physical stresses (either centrifugation at 300xg or a 100 V electrical shock, but not combined). This is the first report on the production of DH plants in borage. Together, the results presented hereby can be used as a basic framework for large-scale generation of DH plants in this important medicinal species.