套种模式下不同株行距核桃对油用牡丹光合特性及产量的影响

Photosynthetic Characteristics and Seed Yields of Paeonia ostii Intercropped with Juglans regia with Different Spacing

利用LI-6400XT便携式光合测量系统,以单作凤丹牡丹为对照,研究了与不同株行距核桃套种模式下油用牡丹的光合特性、水分利用效率及产量构成因素。通过相关性分析和多元逐步回归分析,进一步分析了不同处理内影响牡丹净光合速率(Pn)的主要因子,为油用牡丹高效栽培模式的推广提供参考。结果表明:5种处理下牡丹的光合参数日变化曲线存在较大差异,其中,单作和5 m×6 m株行距套种下牡丹叶片的Pn值日变化曲线为双峰型,存在明显的光合"午休"现象;4 m×5 m、5 m×5 m和4 m×4 m株行距套种下牡丹的Pn值日变化曲线呈单峰型,总体上看,5 m×5 m株行距套种下牡丹在全天中Pn值均最大。多元逐步回归分析显示,不同处理中影响牡丹叶片Pn值的主要因子不同。不同处理下牡丹的光响应参数也具有一定差异。5 m×5 m株行距套种牡丹的表观量子效率(AQE)最高,光合能力最强;与单作相比,4 m×4 m和4 m×5 m株行距下牡丹光饱和点(LSP)高,光补偿点(LCP)低。油用牡丹与核桃树套种时,适当的株行距有利于提高牡丹的光合能力,以5 m×5 m株行距套种最为明显,产量也最高,而株行距过小(4 m×4 m)会导致牡丹减产。

Utilizing Paeonia ostii Fengdan monoculture as experiment control, the photosynthetic characteristics,water use efficiency,yield and its component factors were determined of Paeonia ostii intercropped with Juglans regia with different spacing by using the LI-6400XT portable photosynthesis system.And the main factors affecting net photosynthetic rate(Pn) of Paeonia ostii in the different treatments were analyzed by correlation analysis and stepwise multiple regression analysis,to provide theoretical basis for high-efficiency cultivation of oil peony.The results showed that there were great differences in diurnal change curves of photosynthetic parameters of peony in five treatments.Double-peak type with obvious ‘midday depression’ phenomenon in diurnal change curve of Pn value was observed under the treatment of monoculture and 5 m×6 m plant-row spacing of peony,while that of peony under the treatments 4 m×5 m,5 m×5 m and 4 m×4 m plant-row spacing was single-peak type.Overall,Pn value was the largest throughout the day under the treatment 5 m×5 m plant-row spacing.Multiple regression analysis results showed that main factors affecting Pn value of leaf of peony were different in five treatments.There were also certain differences in light response parameters of peony among five plant-row spacing treatments. Leaves of the peony of the treatment 5 m×5 m plant-row spacing had the highest apparent quantum efficiency( AQE),and the strongest photosynthesis ability.Compared with monoculture treatment,peony under treatments 4 m×5 m and 4 m×4 m plant-row spacing had lower light compensation point(LCP) and higher light saturation point(LSP).In terms of yield,the analysis shows that intercropping Juglans regia in the proper spacing could improve the photosynthetic capacity of peony,in which 5 m×5 m plant-row spacing is highest and so is yield.If the spacing is too much smaller(4 m×4 m),oil peony would reduce production.