In vitro propagation of ten threatened species of Mammillaria (Cactaceae)

Abstract

Mammillaria species are the most numerous within Cactaceae family, and some of them are threatened with extinction as a result of human activities. In this work, results of in vitro propagation are presented for ten Mammillaria species, testing 20 combinations of indole-3-acetic acid (IAA) and kinetin. Best results on shoot formation were obtained using kinetin at two levels: 27.9 and 46.5 μM. All IAA levels tested were able to induce de novo shoot formation in M. bocasana, M. densispina, M. hahniana, M. hutchisoniana, M. orcutii, M. pectinifera, M. perbella, M. picta, M. rhodantha, and M. zephyranthoides.Depending on the IAA level tested, four responding groups were observed concerning their highest shoot-formation number. For all species, the highest average of shoot formation was achieved with 5.7:46.5 or 11.4:46.5 μM IAA/kinetin, yielding 4.8 and 4.7 shoots per explant, respectively, in 60 d. Rooting of regenerated shoots was achieved by leaving the explants in their shoot-induction medium or transferring them to half-strength MS medium. Hardening of regenerated plants was successfully achieved by planting them in peat moss substrate after a desiccation treatment at room temperature for 3 d.

In vitro propagation of purple pitahaya (Hylocereus costaricensis [F.A.C. Weber] Britton & Rose) cv. Cebra

“…According to Aliyu and Mustapha (2007), sprouting of cactus axillary bud requires low levels or no auxin, but always high levels of cytokinins. This was also observed in Nopalea cochenillifera (Brasil et al 2005), in several Mammillaria species (Ramirez-Malagon et al 2007), and in Opuntia ficus-indica (Khalafalla et al 2007). In the present study, inclusion of BAP for axillary bud sprouting of pitahaya cv Cebra was essential (Fig.…”

“…To reduce damage, it was necessary to initially treat larger explants, with five to six areoles each, prior to cutting into smaller segments for in vitro culture. Large explants were also successfully employed for other cactus species with good disinfection and bud sprouting rates (Brasil et al 2005;Ramirez-Malagon et al 2007), and their use has been the preferred way to initiate H. undatus in vitro cultures as well (Drew and Azimi 2002;Mohamed-Yasseen 2002). Contamination rates with our disinfection method (producing over 80 % healthy explants) are comparable with best results published for in vitro cactus bud cultures using field or greenhouse explants (Juárez and Passera 2002), and are considerably better than others in which only 20 % of Values followed by the same letter within a column are not significantly different at the p≤0.05, according Chi-square analysis and Tukey's test explants were successfully established in vitro (RamirezMalagon et al 2007).…”

Influência do substrato e do enraizamento na aclimatização de Melocactus glaucescens Buining & Brederoo propagados in vitro

“…O período de desidratação possibilita a perda de água acumulada em excesso durante o cultivo in vitro, o que evita o apodrecimento das raízes nas condições ex vitro (Ramirez-Malagon et al, 2007). Para as espécies de cactos, a presença de uma matriz parenquimática, que permite a distensão e retração do corpo vegetativo, dependendo da disponibilidade de água, permite que tenham capacidade de se reidratar após o cultivo in vitro (Mauseth, 1993;Malda et al, 1999;Khalafalla et al, 2007).…”

“…Esses resultados demonstram que, para o enraizamento e aclimatização de M. glaucescens, não é necessário o tratamento da planta e do substrato com fungicida, o que discorda dos resultados observados por Ramirez-Malagon et al (2007), que demonstraram que esses tratamentos são fundamentais para espécies de cactos, por causa do apodrecimento das raízes, que ocorre no processo de aclimatização das plantas micropropagadas.…”

Studies on in Vitro Propagation Methods in Cactus Species of the Genera Melocactus, Cereus and Lobivia

“…Micropropagation by axillary shoot proliferation is primarily applied for the conservation of rare and endangered species (Ramirez-Malagon et al, 2007). In addition, the aim can be the mass propagation of plants for commercial purposes (Pérez-Molphe-Balch et al, 2002;Sanchez-Martinez and Hernandez-Martinez, 2002).…”