Gravitropism and phototropism in protonemata of the moss Pohlia nutants (Hedw.) Lindb

The paper focuses on the gravi- and photoresponses of protonemata of Pohlia nutans in an attempt to evaluate the contribution of each of these stimuli to the orientation of protonemal growth. It was found, in particular, that although the cultures under blue light exhibited active growth, no buds were formed. In red light, there was less growth of the protonema, but bud formation was abundant. Pohlia photonemata were demonstrated to have negative gravitropism in darkness, similar to other gravisensitive species. A positive phototropic reaction was observed when exposed to different intensities of white and monochromatic light but there was less sensitivity to lateral blue light. (AIAA)