Use of cactus flowers as explants for micropropagation

Abstract

SummaryFlowers and floral parts have seldom been used successfully as explants to initiate tissue culture. Flower buds of Mammillaria albicoma, M. carmenae, and M. schiedeana (Cactaceae) were cultured on solid Murashige and Skoog medium containing 0.1 mg l−1 -naphthaleneacetic acid (NAA) and 5.0 mg l−1 6-benzylaminopurine. The formation of vegetative buds (areoles) and the development of shoots were observed in all three species. Both direct and indirect mechanisms of shoot morphogenesis were observed. Direct shoot morphogenesis from the perianth (especially from the axils of the perianth segments) in M. albicoma and M. carmenae was confirmed by microscopic examination. Shoots that formed on explants were isolated and used to establish proliferating cultures. Finally, proliferated shoots were rooted in vitro on MS medium containing 0.01 mg l−1 NAA and acclimated to ex vitro conditions. M. carmenae shoots were also rooted non-aseptically in horticultural substrate. This is the first report of the complete micropropagation of cacti initiated from floral explants. In this family of leafless stem succulents, harvesting of flowers may be a convenient way to micropropagate valuable genotypes, as it avoids injury to stock specimens.