Transgenerational effects of rate of drying in the moss Aloina ambigua (Pottiaceae): spore desiccation tolerance

Abstract

  Cultured, uniclonal embryos of the moss Aloina ambigua (Bruch & Schimp.) Limpr. (Pottiaceae) were subjected to four different rates of drying and allowed to develop mature operculate capsules. These capsules were stored for 10 years in darkness at ～23℃ and ～35% relative humidity. Spores from embryos dried slowly tolerated desiccation better than spores from embryos dried rapidly, having a higher germination percentage, an earlier time of germination, a greener color, a larger diameter, and fewer abortive spores. Thus, a stress implemented on the early diploid phase of development (embryo), was manifested as altered stress tolerance (the ability to tolerate long dry periods) in the early haploid phase (spore), perhaps the first report of transgenerational stress effects in bryophytes. Maternal provisioning of greater resources to spores is postulated as the mechanism responsible for a higher desiccation tolerance in spores derived from embryos that were very slowly dried.