Effect of Shading on Photosynthetic Physiological Characteristics of Davallia mariesii

Abstract:

In order to reveal the light response mechanism of Davallia mariesii, the growth, photosynthetic characters and chlorophyll fluorescence parameters were measured under five shading treatments, including 0, 25%, 50%, 70% and 90% shading. The results showed that the leaf type became large and leaf color deepened with the increment of shading. Under 70% shading, the growth vigor of D. mariesii was good with hard glossy leaves, low sporulation rate, and spore maturation delay. The contents of chlorophyll a, chlorophyll b and Chlorophyll a+b increased with increment of shading, but decreased under 90% shading, the chlorophyll a/b, the changes in light saturation point, light compensation point and dark respiration rate were opposite, there was significant difference in light saturation point between deep shading and nature light. Among five shading levels, the chlorophyll fluorescence parameters, such as Fm, φ_Po, ψ_O, φ_Eo, TR_O/RC, ABS/RC, and ET_O/RC, reached up to the maximum under 70% shading. Therefore, D. mariesii had the smallest light inhibition, the largest light energy utilization, and the strongest photosynthetic capacity under 70% shading, so that it was helpful for the growth of D. mariesii.