CHANGES IN LIGHT INTENSITY AFFECT LEAF GAS EXCHANGE, CHLOROPHYLL FLUORESCENCE, AND NONSTRUCTURAL CARBOHYDRATES OF MA BAMBOO (DENDROCALAMUS LATIFLORUS MUNRO)

Many physiological traits are thought to play an important role in the low-light adaptation of plants.Therefore, we tested light intensity regulation of chlorophyll pigments, gas exchange, chlorophyll fluorescence, and non-structural carbohydrates in Ma bamboo (Dendrocalamus latiflorus Munro) leaves under five varying light intensities; such as L0 (100%), L1 (40%), L2 (30%), L3 (20%), and L4 (10%).We found that Ma bamboo grown under low light conditions synthesized more chlorophyll [total chlorophyll (Chls) and carotenoids (Car)], whereas net photosynthetic rate (Pn) under 10-40% light treatments was lower than that of those established under full sunlight.The decrease in light intensities increased PSII actual photochemical efficiency (ΦPSII), electron transport rate (ETR), and PSII photochemistry (Fv/Fm), while low radiation led to a reduction in photochemical quenching coefficient (qP) and an increase in non-photochemical quenching coefficient (NPQ) of the leaves.Low light intensity was more conducive to accumulating non-structural carbohydrates with higher soluble sugar and starch.These parameters analyzed by principal component analysis (PCA) could be considered critical physiological traits to evaluate Ma bamboo's adaptation to low light.Our findings implied that Ma bamboo had better adaptive strategies in low light conditions, which had substantial implications for the management and cultivation of Ma bamboo's plantation.