Confirmation of morphophysiological dormancy in sandalwood (Santalum album, Santalaceae) seeds

Abstract

Indian sandalwood (Santalum album L.) is a hemi-parasitic angiosperm tree grown in India, Indonesia and Sri Lanka primarily for its economically valuable santalum oil. Although the seeds of this species have been reported to have morphophysiological dormancy (MPD), the occurrence of MPD in them or in Santalaceae has never been confirmed. Thus, the present study was conducted with the objective of identifying the class of dormancy present in S. album seeds. Ripened fruits of S. album collected from trees in Peradeniya, Sri Lanka were used to study the (1) imbibition and germination of non-scarified and scarified seeds, (2) effects of ambient laboratory conditions, gibberellic acid (GA3) and dry storage on germination and (3) embryo: Seed length (E:S) ratio for fresh seeds and for seeds soon after radicle emergence. Nonscarified and scarified seeds readily imbibed water. Increased germination with GA3 indicated a physiological component to dormancy, and increased E:S ratio prior to radicle emergence revealed an additional morphological component. Thus, we confirmed the occurrence of MPD in S. album, and suggest that the level is non-deep simple.