大蒜根系水浸液处理对连作甜瓜光合及荧光特性的影响

摘 要：【研究目的】为更有效的缓解甜瓜连作障碍问题，对甜瓜与大蒜间互作效应的研究在理论和应用上都有重要的意义。【方法】以甜瓜品种“金蜜”为材料，盆栽于连作与非连作土壤中，用大蒜根系水浸液处理幼苗，处理后30天，测定叶绿素含量、气体交换和叶绿素荧光参数。【结果】连作使甜瓜叶片光合色素含量、净光合速率（Pn）、气孔导度（Gs）、胞间CO2浓度（Ci）、蒸腾速率（Tr）下降，使甜瓜叶片初始荧光强度（Fo）增加，PSⅡ最大光化学效率（Fv/Fm）、PSⅡ实际光化学效率（ΦPSⅡ）和光化学猝灭系数（qP）下降。大蒜根系水浸液处理连作与非连作甜瓜，均提高叶片光合色素含量、Pn、Gs、Ci、Tr、Fv/Fm、ΦPSⅡ和qP，降低Fo。【结论】甜瓜不适宜连作，大蒜根系水浸液能促进甜瓜生长，缓解甜瓜的连作障碍。

Effects of Garlic Root Aqueous Extracts on the Characteristics of Photosynthesis and Chlorophyll Fluorescence of Melon in Continuous Cropping Soil.

Abstract: 【Objective】It is meaningful to study reciprocity on melon and garlic for relaxing the problem of soil sickness.【Method】contents of chlorophyll and parameters photosynthesis and chlorophyll fluorescence of melon ‘Jinmi’ leaves were measured after planting 30 days. Pot experiment of non-continuous cropping and continuous cropping soil was conducted by using garlic root aqueous extracts treatment. 【Result】The results showed that continuous cropping decreased content of chlorophyll and carotenoid, net photosynthesis rate (Pn), stomatal conductance(Gs),intracellular CO2 concentration and transpiration rate(Tr). Continuous cropping increased original fluorescence intensity(Fo),but deceased maximum photochemical efficiency (Fv/Fm), actual photochemistry efficiency of PSII (ΦPSⅡ), photochemical quenching (qP) of the melon leaves. After treatment of garlic root aqueous extracts, contents of chlorophyll and carotenoid, Pn, Gs, Ci, Tr, Fv/Fm, ΦPSⅡand qP of the melon leaves were increased,while Fo decreased both continuous cropping and non-continuous cropping. 【Conclusion】Melon is a crop that it is not fit for continuous cropping. Garlic root aqueous extracts can promote melon growth and relax the problem of soil sickness.