土壤含水量对牡丹光合特性的影响

Photosynthesis Characters of Tree Peony in Response to Soil Water Content

以盆栽牡丹朱砂磊为试材,研究了5种土壤相对含水量(SRWC)对牡丹光合特性的影响。结果表明,随着土壤水分胁迫程度的增加,光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)逐渐下降,表观量子效率(AQY)、CO2羧化效率 (CE)、光饱和点降低;光补偿点及CO2补偿点升高。干旱胁迫下,光合速率的下降是气孔因素与非气孔因素双重作用的结果:轻度干旱胁迫下(土壤相对含水量55％-40％)气孔限制是光合速率下降的主要原因,而严重干旱胁迫下(土壤相对含水量20％)非气孔限制是光合速率下降的主要原因。牡丹光合作用的最适SRWC为70％左右。

With potted Paeonia suffruticosa Andr. cv. Zhushalei as material, the effect of soil water on the photosynthesis characters of paeoy leaves under five drought stress developing. The results showed that with the soil water stress increasing, the photosynthetic rate （Pn）, transpiration rate （ Tr ）, stomatal conductance （Gs） declined, the apparent quantum yield（AQY）, carboxylation efficiency（CE） and the light saturation point（LSP） reduced ;The light compensation point（LCP） and CO2 compensation point（CCP） enhanced. When the relative soil water content were 55% -40%, the main reasons of the photosynthetic rate declined were stomatic limitation . When the relative soil water content were 20 %, the main reasons of the photosynthetic rate declined were nonstomatic limitation. The optimum SRWC of Pn was 70%.