World's largest collection of moss species

For their project -- called MOOSzucht -- the scientists collected sporophytes, the spore capsules of mosses, of 19 Sphagnum species in Austria, Germany, Latvia, Russia, Sweden, and the Netherlands. The world's largest collection of Sphagnum cultures is now housed in the International Moss Stock Center (IMSC), a resource center founded in 2010 at the University of Freiburg. Scientists use the spores to create pure peat moss cultures in a laboratory environment that are not contaminated by bacteria, fungi, algae, or suchlike. Some species grow at a rate 50 to 100 times faster in the laboratory than in a moor landscape. The researchers measured the growth of the mosses in liquid mediums containing nutrients, also known as suspension cultures. They also determined how many sets of chromosomes could be found in the cell nuclei in the cultures and compared this to the genome size of the already established model moss Physcomitrella patens. In this way they were able to identify haploid and diploid Sphagnum species -- in other words, species with single or double sets of chromosomes, respectively. However, they could not find a correlation between the number of sets of chromosomes and moss growth, meaning it is still unclear why diploid mosses exist in nature.

Peat is harvested on a large scale for growing vegetables and ornamental plants in greenhouses and home gardens. Due to climate change and the resulting droughts and higher temperatures, peat mosses are showing poorer growth, deteriorating more quickly, and binding less carbon. The researchers from the University of Freiburg want to replace this dire need for peat with renewable biomass. However, the large amount of founder material that would be needed for this can only be produced in bioreactors. That is why Reski and his team at the IMSC are distributing lab strains of peat mosses to various research institutes and companies who are active in basic research, biotechnology, or in sustainable bioeconomy.