Effect of light intensity on survival, growth, and photosynthetic pigment of young seedlings of eelgrass Zostera marina Linnaeus, 1753 (Alismatales: Zosteraceae)

AbstractWe subjected young, seed-generated plants of Zostera marina Linnaeus, 1753 to different light intensities (0, 4, 10, 25, 130, 195, 327 and 373 µmol m−2 s−1, in sunlight) for over 30 days under controlled laboratory conditions. The light treatments were categorized into four light levels, namely, 0 µmol m−2 s−1; below compensation point (BCP; 4, 10, 25 µmol m−2 s−1); saturation light (SL; 130, 195 µmol m−2 s−1); and above saturation (AS; 327, 373 µmol m−2 s−1). We measured plant response in terms of survivorship, morphology, growth, and leaf pigment concentration. The survival rate of young seedlings exposed to 0 µmol m−2 s−1 was significantly lower at 23.3% compared with seedlings under other light intensities, whose survival rates were above 60%. The leaves of the seedlings under 0 µmol m−2 s−1 and AS level became partially brown and wilted after 30 days. Morphological analysis combined with dynamic assessment suggested that the optimum light intensities for the growth of young Z. marina seedling...