Abstract
Osmunda lancea is the rheophyte which is considered to have speciated from O. japonica and has an adaptive morphology, stenophylly. In order to clarify the genetic architecture of stenophylly, using the spores collected from a putative F1 hybrid, F2 hybrids were synthesized. The six leaf characters were measured in the F2 hybrids with ternate compound leaves. As the results, the angle of pinna base is significantly correlated to the number of veinlets in most basal basiscopic vein and that in most basal acroscopic vein, and the correlation coefficients were 0.520 and 0.426, respectively. Based on the results of molecular marker analyses, a locus appeared to be associated with the angle of pinna base, but this locus was not associated with the other measured characters.
