Efecto de las condiciones de almacenamiento en la germinación de semillas de Tillandsia spp. (Bromeliaceae)

Abstract

The family Bromeliaceae is widely distributed in Mexico, the genus Tillandsia is the most diverse (192 species) showing high endemism. The genus is characterized by bracts and flower stalk with showy inflorescences, Tillandsia plants with inflorescences of colors have a high market demand in regional markets and causes severe poaching pressure on wild populations, coupled with the loss of their habitat. This problem has endangered many of them, which is why it is important to develop strategies and conservation actions. From February to June 2010 in the temperate forests of Santa Catarina Ixtepeji, Sierra Norte of Oaxaca, Mexico. Seeds were collected Tillandsia prodigiosa, T. bourgaei, T. carlos-hankii, T. fasciculata, T. makoyana, T. violacea, were evaluated for physical quality and germination capacity through X-rays and a germination test to estimate the quality of seeds. Significant differences in the proportion of full seed (viable) and incomplete. The number of empty seeds did not show significant differences. The evaluated species differed in their germination capacity. The germination pattern was repeated in the germination rate. The proportion of full seeds (radiographic analysis) and germination showed a significant positive correlation. Subsequently, in order to understand the behavior of storage, germination capacity was evaluated in terms of moisture loss in a test of drying at 60 °C. Initially seed germination showed 72.4% on average, when the humidity dropped to 3.3% germination remained at approximately 30%, so are classified as orthodox, because they can be dried and stored without a drastic loss of viability. In a third phase in order to evaluate the temperature and storage time, the effect on germination of four storage temperatures (-20 °C, 0 °C and 10 °C plus a control at room temperature), every three months (from 0 to 12 months). To determine whether there were significant differences in germination among species, time and temperature of storage, a standardized data underwent an analysis of variance. When significant differences between the factors of variation is made a multiple comparison of means by Tukey test (P ≤ 0.05). Significant differences in the factors evaluated. There was no loss of viability of five of the six species assessed at 12 months of storage, therefore Tillandsia seeds can be stored, preferably at low temperatures without affecting its germination.