Effects of Different Extracts from Phyllostachys edulis on the Growth Index and Photosynthesis Characteristics of Corydalis yanhusuo

A pot experiment was carried out to study the effects of different concentration of extracts from Phyllostachys edulis forest (root system, fresh branches and leaves, litter, 0−20 cm soil) on the growth index, chlorophyll content and photosynthesis characteristics of Corydalis yanhusuo under treatments of CK (0 g/mL), T1 (0.005 g/mL), T2 (0.01 g/mL), T3 (0.02 g/mL) and T4 (0.1 g/mL). The results showed that plant height, fresh weight, dry weight and chlorophyll content of C. yanhusuo showed low concentration promotion and high concentration inhibition in all 4 extracts. And the allelopathic sensitivity index (RI) was consistent with its change. However, there was no significant change in the plant height of each treatment group compared with the control group . The net photosynthetic rate (P_n) of C. yanhusuo was affected by the 4 kinds of extracts, and generally decreased with the increase of the concentration of the extract. The maximum net photosynthetic rate and light saturation point of C. yanhusuo showed a trend of increasing first and then decreasing with the increasing concentration, while the apparent quantum yield increased with the increase of extract concentration. The sensitivity of C. yanhusuo to the comprehensive inhibition of 4 extractive liquefaction sensitivities was different, and the order from big to small was litter, fresh branches and leaves, 0−20 cm soil and root. The growth index and photosynthesis characteristics of C. yanhusuo under the P. edulis forest showed low concentration promotion and high concentration inhibition. The inhibition of T4 concentration was significant and litter extract had the greatest inhibitory effect. Therefore, it is necessary to pay attention to the cleaning of P. edulis litter when developing the three-dimensional management of C. yanhusuo under the P. edulis forest.