SEED VIABILITY AND GERMINATION OF SIX SPECIES OF Tillandsia (BROMELIACEAE) FROM OAXACA, MÉXICO

Abstract

Understanding the seed ecophysiology of native species of Tillandsia is crucial to design ex situ and in situ conservation strategies for Mexican gene pools. In the present work, seed viability and germination capability of six species of the Tillandsia (Bromeliaceae) genus were evaluated using seed collected from February to July 2010, at Santa Catarina Ixtepeji, Oaxaca forest. All seed lots were evaluated by X-rays and germination tests (at constant temperature of 25 ºC and neutral photoperiod), both tests under a completely random design with a minimum of 6 replicates of 50 seeds each. Significant differences (P < 0.05) were observed among Tillandsia species in relation to full or complete (viable or structures completely developed) and incomplete seed percentages. T. violacea presented the lower percentage of full seeds (61.3 %) and higher percentage of seeds with structures partially developed (31.6 %), compared to T. prodigiosa, T. carlos-hankii, T. bourgaei, T. makoyana and T. fasciculate which showed values between 68.3 and 89 % of full seeds and 4.5 to 15.0 % of incomplete seeds. T. bourgaei presented the highest percentage of germination capability (83.3 %), followed by T. makoyana (79.8 %), T. carlos-hankii (79.5 %), T. prodigiosa (75.8 %), T. fasciculata (45.0 %) and T. violacea (15.16 %). A positive and significant correlation (r = 0.69, P < 0.05) was determined between the percentages of full seed from the X-rays test and germinated seeds in the germination test.