© 1989 Heron Publishing—Victoria, Canada
Adventitious roots, leaf abscission and nutrient status of flooded Gmelina and Tectona seedlings
M. A. Osundina (1) and O. Osonubi (1, 2)
1. Department of Botany and Microbiology, University of Ibadan, Ibadan, Nigeria / 2. Author to whom correspondence should be addressed / Received September 29, 1988
Summary
When flooded, seedlings of Gmelina arborea Roxb. produced more adventitious roots, had lower foliar Mn concentrations and lost fewer leaves than seedlings of Tectona grandis L.f. Severing the adventitious roots produced by flooded Gmelina seedlings increased leaf Mn concentration and leaf abscission and reduced whole-plant dry matter production. Flooded Gmelina cuttings, which do not produce adventitious roots, abscised few leaves until foliar concentrations of Mn and Fe had risen
substantially above those of unflooded cuttings, at which time most leaves were shed. The results indicate that the development
of adventitious roots in flooded seedlings of Gmelina suppressed uptake of Mn thereby minimizing leaf abscission.
