SPORE GERMINATION AND GAMETOPHYTE DEVELOPMENT IN 3 SPECIES OF ASPLENIUM

Laboratory and field experiments involving Asplenium ruta-muraria L., Asplenium trichomanes L. subsp. quadrivalens D.E. Meyer emend. Lovis and Asplenium scolopendrium L. [= Phyllitis scolopendrium (L.) Newm.] revealed differences in their temperature requirements for germination and in their sexual development on soil. The germination responses of A. trichomanes and A. scolopendrium to culture temperatures of 10, 15, 20 and 25 °C were very similar and all spores were able to germinate at 10 °C. Spores of A. ruta-muraria differed in that germination was slower at 15-25 °C and very much delayed, or even inhibited, at 10 °C. Both laboratory and field cultures of A. trichomanes and A. scolopendrium produced male, female and bisexual gametophytes whereas those of A. ruta-muraria produced only males and bisexuals. The ecological significance of these differences is discussed.