Physiological and morphological responses of the seagrass Zostera capricorni Aschers, to light intensity

摘要: The responses of the seagrass Zostera capricorni Aschers, to changes in light intensity were examined flowing seawater aquaria experiments. Plants grown six regimes: full sunlight (100%), 50, 30, 20, 15, and 5% over a 2-month period. Measurements growth, biomass, pigments, stable isotopes leaf anatomy made at end experiment. survived under all treatments, even below minimum requirements related seagrasses. However, experimental levels possibly do not correspond reaching leaves natural conditions. high conditions (50–100% light) had smaller shoots, higher biomass productivity, less negative δ13C values, lower nitrogen content, chlorophyll more ultraviolet absorbing pigment than plants low (<20% light). Photoadaptation by pigment(s) was noted, with variability pigments levels. Increased CO2 demand and/or increased recycling internal gas spaces may account for values indicating isotopic discrimination light. A saturation response growth rates observed, substantial reductions intensities observed other shading Nutrient limitation inferred maximum 50% level, root content treatments. Overall, wide range morphological physiological photoadaptive previously reported observed.