遮荫对引种玉簪生长及光合特性的影响

Effects of Shading on the Growth and Leaf Photosynthetic Characteristics of Introduced Hosta

通过研究不同光照强度对引种玉簪(Hosta)的生长及光合作用的影响,为不同品种玉簪进行园林配置提供必要的理论依据。对初期筛选获得的3种引种玉簪及对照东北玉簪进行不同遮阴处理,通过测定株高、生物量以及净光合速率(Pn)、气孔导度(Cond)、胞间CO2浓度(Ci)和蒸腾速率(Tr)的日变化,分析不同遮阴处理条件下引种玉簪的生长特性和光合特性。结果表明:不同遮光处理下,S25组的3种引种玉簪和东北玉簪的株高变化不显著,而S50和S75组中玉簪T和F的株高显著降低,玉簪S与东北玉簪无显著变化;除玉簪S和东北玉簪外,其他玉簪的根部组织干重随着遮光度的增加而降低。3种引种玉簪和东北玉簪的净光合速率、气孔导度、胞间CO2浓度和蒸腾速率变化趋势一致;S25组的玉簪S在12:00时的净光合速率显著增加,高于S0组30.5%;玉簪F和玉簪S的气孔导度在不同遮阴组中的峰值均显著高于无遮阴S0组;S75组中玉簪F的胞间CO2浓度在16:00时显著增加,高于无遮阴S0组16.39%;遮阴后的玉簪T和F的蒸腾速率在12:00时显著升高,玉簪S的蒸腾速率在不同时间点均显著升高。因此,玉簪S在较强的遮阴条件下生长较旺盛,光合作用较强。

To provide the necessary theoretical basis for the application of different Hosta, the effect of different light intensity on growth and photosynthesis of introduced Hosta were studied. The introduced Hosta in the early screening and the northeast Hosta as the control were under the different conditions of shade, and the plant height, biomass and the diurnal variation of Pn, Cond, Ci and Tr were detected, which analyzed the growth and photosynthetic characteristics of the introduced Hosta under the different conditions of shade. The results showed： the height changes of three kinds of Hosta were non-significant in S25, and the height of T and F was significantly decreased in S50 and S75, while that of S and E were no-significant; except for S and E, the dry weight of root of T and F was decreasing in different conditions of shade. The variation trend of net photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate of introduced Hosta and northeast Hosta was the same; the net photosynthetic rate of S was significantly increased at 12 o＇clock in S25, and higher by 30.5%than that in SO; the peaks of the stomatal conductance of F and S were higher in all of the conditions of shade than that in SO; the intercellular CO2 concentration of F at 16 o＇clock in S75 was significantly higher by 16.39% than that in SO; the transpiration rate of T and F at 12 o＇clock under the shade was significantly increasing, and that of S was significantly increasing in different time. So the growth of S was more vigorous, and the photosynthetic characteristics of S were also more stronger.