为探究狗牙根(C)与牛鞭草(H)当年生扦插苗在不同水淹地区较优的密度配置,于2016年4月29日在盆栽控制条件下设置3种不同水分条件(对照组-CK组、浅淹组-SF组、全淹组-TF组)、7种牛鞭草与狗牙根配置比例(每盆牛鞭草与狗牙根株数分别按2株进行递增与递减),具体配比分别为H0C12、H2C10、H4C8、H6C6、H8C4、H10C2和H12C0,对混植条件下牛鞭草与狗牙根在水淹环境中的生长及光合作用进行了比较研究.结果表明:水淹和密度配置对狗牙根、牛鞭草的净光合速率有极显著的影响(P＜0.01).CK条件下,牛鞭草在密度H2C10下的净光合速率显著高于牛鞭草单植条件下的净光合速率(P＜0.05),狗牙根在混植条件下的净光合速率与单植相比显著降低(P＜0.05);SF条件下,牛鞭草在密度H8C4下的净光合速率显著大于其他密度下的净光合速率,而狗牙根单植下的净光合速率与混植相比显著降低(P＜0.05);与对照组相比,牛鞭草在TF组的净光合速率显著降低(P＜0.05).综合考虑混植体系的整体光合效率,建议在三峡库区无水淹地区混植牛鞭草与狗牙根的最佳密度配置为H2C10;在浅水淹地区,采取最佳密度配置为H8C4;在较低海拔的全淹地区,采取单植牛鞭草的方式将是更为理想的选择.%This research aimed to investigate the photosynthetic responses of Cynodon dactylonand Hemarthria altissima under different flooding conditions and to identify a suitable planting pattern.On April 29, 2016, a pot experiment was set up with a replacement series design in which H.altissima (H) and C.dactylon (C) were planted at seven ratios (H0C12, H2C10, H4C8, H6C6, H8C4, H10C2, and H12C0) under three water treatments, including normal growth water condition (CK), flooding at 10 cm above the soil surface (SF) and flooding at 2mabove the soil surface (TF).The flooding and density treatments had significant (P＜0.05) effects on net photosynthetic rate (Pn) of H.altissimaand C.dactylon.Under the CK water treatment, the Pnof H.altissima with the H2C10 ratio was greater than that with the monoculture, and the Pnof C.dactylon significantly decreased under the mixed intercropping conditions when compared with that under the monoculture conditions (P＜0.05).Under the SF treatment, the Pnof H.altissima with the H8C4 planting ratio was greater than that at other planting densities, while the Pnof C.dactylonin monoculture was lower than that achieved under mixed intercropping (P＜0.05).Compared with the CK treatment, the Pnof H.altissimasignificantly decreased (P＜0.05) under the TF water treatment regime.Taking photosynthetic efficiency of the two species into consideration, the results suggested that a mixed intercropping pattern with a planting ratio of H2C10 should be adopted in high-altitude areas where no water flooding occurs, and the H8C4 ratio should be adopted in areas where the soil surface is flooded.The monoculture of H12C0 is the optimal choice for low-altitude areas where complete flooding often takes place.
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