THE EFFECT OF SURFACE STERILIZATION ON CULTURES OF CERATOPTERIS-RICHARDII GAMETOPHYTES

Gametophytes of Ceratopteris richardii were grown as single-spore and double spore cultures on agar to test the effects of surface steriliza tion of spores (with bleach) and contamination of cultures on growth a nd sexual expression. Hermaphroditic gametophytes were larger in doubl e-spore than in single-spore cultures for cultures derived from both u ntreated and sterilized spores, whereas gametophytes were larger in si ngle-spore than in double-spore cultures in contaminated cultures. How ever, gametophytes did not differ in size between double-spore and sin gle-spore cultures derived from surface sterilized spores. The greates t antheridiogen response was observed in cultures with no treatment an d the least antheridiogen response was observed in contaminated cultur es.