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 santalumoil.
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.