Short Communication<br><br>Seed development, morphology and quality testing in selected species of the nut-fruited Restionaceae

Abstract

Seed germination is poor in species of the nut-fruited Restionaceae.
Investigations of seed morphology and development, seed collection and sorting,
and seed viability were conducted in species of Cannomois Desv., Hypodiscus Nees
and Willdenowia Thunb. to supplement existing knowledge, and to determine
whether poor seed quality resulted in the poor seed germination identified
in previous studies. Suitability of collection methods and the effectiveness
of sorting techniques were evaluated using x-radiography. Shaking and ground
collection methods yielded consistently higher proportions of full seed than
extracting seed from cut shoots. However in species with bony bracts and few
seeds per plant, the cutting method was more suitable. Floating was a better
seed sorting technique than weighing for separating full from incompletely
filled seeds. Seed viability in seed collections that had been sorted to contain
only fully developed seeds was assessed using tetrazolium salts. Viability
was generally high (mostly >80%), suggesting that poor germination in studies
with well-sorted seeds is likely to be due to seed dormancy.

South African
Journal of Botany 2002, 68: 226–230