米奴塔睡莲对弱光环境的生理生化响应.

【Objective】 The present paper aimed to explore the physiological and biochemical response of Nymphaea minuta to low light environment, and to provide theoretical basis for seedling breeding and potted flower production management of micro-tropical water lily represented by N.minuta. 【Method】 A completely random experimental design was conducted. The shading treatments were set to 0(total illumination control, CK), 30% (light shading), 50% (medium shading), 70% (heavy shading) respectively by constructing shading nets with different layers. The number of leaves, leaf dry weight, leaf area and other growth indicators were measured by shading treatment for 120 days. The content and composition of photosynthetic pigments, soluble sugar, soluble protein and starch contents were measured by shading treatment for 30, 60, 90 and 120 days respectively. The effects of different shading conditions on leaf growth, photosynthetic pigment content and primary metabolites content of N.minuta were analyzed. 【Result】 During the shading period of 30-120 days, there were no significant differences between the average leaf area, photosynthetic pigment content, and soluble protein content of N.minuta treated with shading rate of 30%, 50% and CK (P＞0.05). After shading treatment for 120 days, the leaf number, average leaf dry weight, specific leaf weight, soluble sugar content, soluble protein content and starch content of N.minuta decreased with increasing shading rate, while total chlorophyll content, chlorophyll a content, chlorophyll b content, chlorophyll a/b content and carotenoid content all increased with increasing shading rate. Comparing with CK, the shading rate of 70% at 120 days treatments, the leaf number, average leaf dry weight and specific leaf weight of N.minuta were significantly decreased by 52.9%, 81.3% and 57.8%, respectively (P＜0.05, the same as below), total chlorophyll content, chlorophyll a content, chlorophyll b content and carotenoid content were significantly increased by 108.7%, 81.6%, 237.5% and 88.2% respectively, chlorophyll a/b content was significantly decreased by 39.1%, soluble sugar content, soluble protein content and starch content were significantly decreased by 43.4%, 56.2% and 53.2% respectively. The results of correlation analysis showed that the leaf number and average leaf dry weight were extremely positively correlated with soluble protein content (P＜0.01, the same as below), and the average leaf dry weight was negatively correlated with total chlorophyll content, chlorophyll a content, chlorophyll b content and carotenoid content. 【Conclusion】 N.minuta grew well in light and medium shading environments with shading rates of 30% and 50%, showing good light adaptive response and regulation ability. These two shading methods can be used for reference in the breeding of micro-tropical waterlily seedlings and potted flower production management. [ABSTRACT FROM AUTHOR]