不同地黄品种光合特性的比较研究＊

目的 地黄为我国重要中药材,栽培品种较多,通过对10个地黄品种的光合特性进行比较研究,为优选地黄优良品种提供科学依据。方法 在地黄种质资源圃,采用便携式光合作用测定仪Li-6400,分别测定地黄叶片的净光合速率、蒸腾速率、气孔导度和胞间CO₂浓度、光饱和点和光补偿点、CO₂饱和点和CO₂补偿点,并用方差分析和相关性分析对不同地黄品种的光合特性进行综合评价。结果 10个地黄品种的叶片净光合速率、气孔导度、胞间CO₂浓度、水分利用效率和蒸腾速率在品种间存在显著差异。10个地黄品种的光补偿点间和CO₂饱和点间有差异,但光饱和点和CO₂补偿点在品种间差异不显著。通过对10个地黄品种的光合参数作相关分析表明,叶片净光合速率主要受气孔导度和蒸腾速率的影响,与环境温度和湿度的关系不显著。结论 10个地黄品种中金九、沁怀1号、怀丰和红薯王的综合光合特性优于其它品种。本实验得到的研究数据对于指导地黄的品种选育具有一定的指导意义,但应和不同地黄品种的质量评价相结合,才能获得更能反映光合特性与其质量之间的关系模式。

Comparison of Photosynthetic Characteristics of Different Germplasm Rehmannia Glutinosa

The photosynthetic characteristic of 10 germplasm of Rehmannia glutinosa was studied under field condition to provide scientific basis for optimizing germplasm resources. The net photosynthetic rate (Pn), transpiration rate(Tr), a stomata conductance (G_s) , intercellular CO₂ concentration (Ci) , light compensation point, Light saturation point, CO₂ compensation point and CO₂ saturation point were measured by means of LI-6400XT Portable Photosynthesis System within vinyl tunnel and the comprehensive evaluation of photosynthetic characteristics were analyzed with variance and correlation analysis. The results showed that the photosynthesis parameters of 10 rehmannia germplasm resources were obviously different and there was a significant correlation between Pn and Gs, Tr. According to the results from clustering analysis, 10 rehmannia germplasm were classified into four groups, the photosynthesis characteristic of Jinjiu, Qinhuai 1, Hongshuwang, Huaifeng have higher photosynthesis characteristics than other germplasm. The basic data obtained in this experiment have certain guiding significance for the breeding of Rehmannia, but it should be combined with the quality evaluation of different Rehmannia varieties to obtain a more reflective model of the relationship between photosynthetic characteristics and its quality.