Abstract

ZURITA-VALENCIA, Wendy et al. Establishment of an efficient method of in vitro germination and micropropagation of the cirimo tree (tilia mexicana schlecht. ) (tiliaceae). Polibotánica [online]. 2014, n.38, pp.129-144. ISSN 1405-2768.

To achieve an efficient method of germination and micropropagation of Tilia mexicana Schlecht. (cirimo), seeds recently collected at time of fruiting, were in vitro cultured. Previously to in vitro culture in Murashige and Skoog (MS) nutritive medium with 30 g/L of sucrose, 8 g/L of agar and 0.05 mg/L of benzyladenine BA, seeds were subjected to surface disinfection and different methods of scarification. After 60 days cultured, the highest percentage of germination was 74% in seeds treated with HCl 10% for 5 minutes, allowing optimal development and a major number of seedlings. The seedlings 90 days of cultivation were 4.5 cm in height, with leaves and well-developed roots, these plants were used for the micropropagation protocols. The shoot multiplication was obtained through the axillary buds cultured in MS medium with different concentrations of auxin/cytokinin (NAA/BA). The largest number of shoots (7.75 shoots/explant) was obtained with the addition of naphthalene acetic acid (NAA) (0.25 mg/L) in combination with BA (1.0 mg/L) at 60 days of cultured. The regenerated shoots were cultured in MS medium supplemented with indolbutyric acid (IBA), showing 100% rooting with 5.0 mg/Lat the 45 days of cultivation.The micropropagated T. mexicana plantlets showed on average a height of 4.51 cm, producing 3.3 roots/plantlet of 2.27 cm in length, those were transplanted and acclimatized in growth chamber conditions, then be grown in a greenhouse. After 90 days of cultivation in the greenhouse, 70% of survival was observed.

Keywords : Tilia mexicana; in vitro culture; axillary buds; shoot multiplication; scarification.