Aquatic adventitious root development in partially and completely submerged wetland plants Cotula coronopifolia and Meionectes brownii

摘要: BACKGROUND AND AIMS: A common response of wetland plants to flooding is the formation aquatic adventitious roots. Observations root growth are widespread; however, controlled studies roots terrestrial herbaceous species scarce. Submergence tolerance and physiology were evaluated in two herbaceous, perennial Cotula coronopifolia Meionectes brownii. METHODS: Plants raised large pots with 'sediment' nutrient solution then placed into individual tanks shoots left air or submerged (completely partially). The effects on removal, light availability plant organs, evaluated. Responses porosity, chlorophyll underwater photosynthesis, studied. KEY RESULTS: Both tolerated 4 weeks complete partial submergence. Extensive, photosynthetically active, grew from stems contributed up 90 % total dry mass. When pruned, completely less had lower stem leaf a, as compared controls intact Roots exposed lowest PAR (daily mean 4.7 ± 2.4 µmol m(-2) s(-1)) under water contained chlorophyll, but there was no difference biomass after weeks, regardless column (high available all emergent shoots). CONCLUSIONS: M. brownii C. responded submergence roots, which essentially replaced existing sediment system. These active. Removal negative during