Effects of light and diaspore type on the regeneration and growth of two Sphagnum species collected from two New Zealand locations

Abstract

Commercial exploitation of Sphagnum, and the associated endeavours to cultivate it, has increased the need for more information about factors that affect its regeneration and growth. Segments of Sphagnum australe and S. cristatum collected from two locations were grown under controlled conditions and various light levels. Short stem segments (25 mm) with the capitulum attached accumulated most dry matter and had greatest extension growth after 13 weeks. Capitula alone had only about half the dry matter growth of short stems with capitula, and 25 mm stem segments without capitula showed the least growth. However, initiation of new capitula was greatest from stem segments without capitula. After 13 weeks, S. australe segments had achieved a similar length to S. cristatum but had approximately 20% more biomass. Moss from the two locations had different growth rates. It was unclear whether differential growth rates could be attributed to genotype or to environmental effects. Photosynthetic quantum yield was consistent with differences in dry matter accumulation between locations, but not between species.