INFLUENCE OF THE HERBICIDE ORYZALIN ON THE SPOROPHYTIC MORPHOGENESIS OF EQUISETUM-ARVENSE

Sporophytic shoot primordia are initiated on gametophyte tissue of Equ isetum arvense when cultured in a medium supplemented with cytokinin. The initiated shoots can develop on a cytokinin-free medium. Oryzalin, a dinitroaniline herbicide, inhibited the initiation and development of sporophytic shoots. But gametophytic growth with normal morphogenes is was not inhibited by oryzalin. These results suggest that some alte ration induced by oryzalin is fatal to sporophytic, but not to gametop hytic morphogenesis. Histological features in relation to the inhibiti on of sporophytic morphogenesis by oryzalin are discussed.