Clonal propagation of Turbinicarpus laui Glass & Foster, a cactus threatened with extinction

Abstract

This work describes the in vitro propagation of Turbinicarpus laui, a Mexican cactus considered as threatened with extinction. In vitro cultures were initiated using seeds. Five shoots per explant of T. laui were obtained on MS medium with 2.2 μM benzyladenine and two shoots on medium with 4.4 μM benzyladenine (P < 0.05) at 40 days. Quality of shoot was recorded as percentage of callus and hyperhydricity. The presence of callus was similar in both media at 20 days, but a reduction was observed at 40 days. A higher number of shoots with low hyperhydricity was obtained on medium with 4.4 μM benzyladenine. The development of shoots (measured as increase on epicotyl length, and fresh and dry weight after 6 weeks) was similar in both media. A continuous increase (15 to 20%) of new shoots was observed after subcultures and in about 1 year 1,200 well defined shoots of T. laui were obtained. Rooting of T. laui shoots was observed on media MS containing 1% polyethyleneglycol and 1% activated charcoal and the survival of the plants to soil was 80%. The first flowering was observed after 2 years in greenhouse conditions.