温度对七叶一枝花光合特性及皂苷含量的影响

该研究以珍稀濒危药用植物七叶一枝花(Paris polyphylla)为材料,利用人工气候箱设置3个温度条件,即低温(10℃/16℃)、适温(18℃/24℃)、高温(26℃/32℃),采用盆栽法分析了不同温度条件对七叶一枝花光合特性和主要有效成分皂苷含量的影响。结果表明:(1)适温条件下,七叶一枝花叶绿素含量、最大光合速率、光饱和点、表观量子效率均高于低温和高温处理,而光补偿点、暗呼吸速率则低于两者。(2)适温条件下,七叶一枝花根茎体内皂苷含量最大,达到了4.33%,低温和高温处理下皂苷含量分别只有适温的42.26%和33.49%,氨基酸含量同样表现为适温处理下最大。(3)七叶一枝花有效成分含量与叶片叶绿素含量、光合速率呈显著正相关,而与呼吸速率呈显著负相关,说明温度直接影响植株的光合作用、呼吸作用,进而影响有效成分的积累。温度对七叶一枝花光合特性及有效成分的积累影响显著,22℃左右的平均温度(18℃/24℃)是七叶一枝花栽培的适宜温度,此温度有利于其生长及有效成分的积累,该研究结果为七叶一枝花人工栽培中温度的科学管理提供了依据。

Effects of temperatures on photosynthetic characteristics and saponins of Paris polyphylla

In order to provide scientific basis for temperature management in artificial cultivating, the photosynthetic characteristics and content of main effective constituents of saponin of the rare and endangered medicinal plant Paris polyphylla with the treatments of different temperatures were studied by using pot experiment. Three different tempera-ture conditions were controlled by artificial climate boxes, namely low-temperature treatment( 10℃/16℃) , appropri-ate-temperature treatment(18℃/24℃), high-temperature treatment(28℃/32℃). The results were as follows: (1) under appropriate temperature treatment, the indexes such as chlorophyll content, maximum net photosynthetic rate, light saturation point, apparent quantum yield were all higher than low and high temperature treatments, while the light compensation point and dark respiration rate were lower than them. ( 2 ) The total saponin content in roots of P. polyphylla was the highest under appropriate temperature treatment, which reached 4.33%. And the percents of sapo-nin content under low and high temperature treatments were only 42.26%and 33.49%of the content under appropriate temperature treatment. The amino acid content was also the highest under appropriate temperature. ( 3) The effective component content of Paris polyphylla was significantly positively correlated with chlorophyll content and photosynthetic rate and negatively correlated with respiration rate, which explained that temperature directly affected photosynthesis and respiration, and then affected the accumulation of effective components. It meant that temperature had significant impacts on photosynthetic characteristics and effective contents accumulation of P. polyphylla. The average temperature of 22 ℃( 18℃/24℃) was conductive to the growth and effective components accumulation and it was the suitable cul-tivation temperature of P. polyphylla.