Abstract
Antheridium of L. japonicum is known to be induced by GA methyl ester. We earlier found that progesterone strongly inhibits GA4-Me induced antheridium formation. This paper reports that IAA and ABA strongly inhibited antheridium formation of L. japonicum. IAA was more biologically active than ABA and progesterorone, 3 times and 14 times, respectively. Protonemal elongation was enhanced by IAA but inhibited by ABA. No biological activity of brassinosteroids, brassinolide and castasterone, was observed in this biological system.
