Effects of gibberellin and stevioside on the maturation in germling stage of Eisenia arborea gametophytes

Abstract

The effects of gibberellin (GA3) and stevioside, plant growth regulators, on the maturation and growth of gametophytes of Eisenia arborea were investigated. Zoospores collected from sporophytes were cultured in 500 µM gibberellin and stevioside. The cell number of female gametophytes in gibberellin was lower and the cell size was larger than those in the control medium. The maturation rate of female gametophytes was 77.0% in the control medium, while it reached 99.0% in stevioside after 17 days culture. The oogonia number per gametophytes was 0.39/ind. in control, while it was 1.71/ind. in gametophytes cultured in gibberellin. No oogonium formation was observed on the gametophytes cultured in stevioside. These results indicate that gibberellin acts as a maturation stimulator and stevioside acts as an inhibitor of germling stage of E. arborea gametophytes. Both GA3 and stevioside will be useful for the efficient control and maintenance of Eisenia arborea gametophytes.