Philippine Journal of Science
142(3): 69-82, Special Issue
ISSN 0031 - 7683
Role of Light in the Life Stages of Mt. Makiling Populations of Alocasia zebrina, An Endangered Philippine Plant Species
Niko Niño G. Briones and Virginia C. Cuevas
Institute of Biological Sciences (IBS), College of Arts and Sciences,
University of the Philippines Los Baños (UPLB), College, Laguna, the Philippines
ABSTRACT
Populations of Alocasia zebrina growing in a secondary forest on Mt. Makiling were studied to determine the influences of sunlight on its life stage development. The study site was dominated by Swietenia macrophylla in association with some members of Palm family. Large canopy gaps were present that allowed ground penetration of high light intensity. The life stages of Alocasia zebrina were identified to be, namely seed, juvenile, adult vegetative and adult sexually mature, based mainly on the number of mature leaves and reproductive capability. Statistical analyses showed a positive correlation between the number of mature leaves and the increase of total monthly minutes of sunshine. Furthermore, the field data analysis suggested that light plays a major role in determining not only where A. zebrina population will be established, but also the rate at which an individual can complete an entire life cycle.
INTRODUCTION
Except for A. macrorrhizos (L.) G. Don, all indigenous species in the genus Alocasia are endemic in the Philippines (Medecillo et al. 2007). Alocasia zebrina Schott ex van Houtte of the Family Araceae is a herb with leaves that grow together in a sympodial manner and found in rainforests at low to medium elevations of Quezon, Bicol, Leyte, Samar, and Mindanao. Hay (1999) has the following description of Alocasia zebrina - The glossy green leaf blade of about 80 cm long has its base bisected into narrow triangular lobes with the anterior end also triangular to ovate in shape. Four to 10 primary lateral veins that arise in almost perpendicular manner from the midrib run roughly straight to . . . . . read more
