Seed germination and predation of the tropical monocarpic palm tree Corypha umbraculifera
R.P.V.G. Subhashi W. Rajapakshe, K.M.G. Gehan Jayasuriya, Sanath Rajapakse and D.H.P. Peramunugama
Published on: 07 April 2017
|2017 vol.62 no.2 pp.129-138
Corypha umbraculifera L., the long lived monocarpic palm belonging to Arecaceae, is rare in the wild and is a possible candidate, which can be developed as an economic plant in Asia. However, little information is available about propagation of this species from seeds. Thus, we aimed to investigate the basic seed biology of this species and to facilitate its propagation and conservation. Effects of light and temperature on seed germination were studied. Morphology of seed germination and embryo: seed ratio were recorded. Seed predation percentages, initial moisture content and nutrient content were determined and optimum storage conditions identified. The highest germination percentage was in light/dark at 25 ˚C. In two trials, of 38.66 and 31.66 % of the seeds were predated. Total energy value of seeds was higher than that of Cocos nucifera, a common known polycarpic palm. Seeds of C. umbraculifera have morphophysiological dormancy as evidence by embryo growth prior to radicle emergence and the relatively long time (42-49 days) taken for completion of germination. Low predation percentage and slow germination rate indicate that the predator satiation hypothesis is not sufficient to describe the evolution and existence of monocarpy in C. umbraculifera. Decreased viability during dry storage at ambient room conditions and a moisture content of 16 ± 3 % indicate that seeds have intermediate storage behaviour. Storage in open polythene bags at 8 ˚C is suggested as the best storage condition for C. umbraculifera seeds.
Keyword: Conservation, Corypha umbraculifera, Morphophysiological dormancy, Seed predation, Seed storage, Semelparity