Effect of actinomycetes on potato growth and PPO activity during seedling stage in continuously cropped soils | 放线菌剂对连作番茄苗期生长和PPO活性的影响

صينى. 研究番茄不同连作年限的土壤在增施放线菌剂后，对苗期植株生长和多酚氧化酶（PPO）活性的影响，为探索放线菌剂在改良土壤连作中的作用提供参考。以“金鹏一号”番茄为试材，棚外未种植过番茄的土壤和棚内连作4、8年番茄的土壤为介质，分别设施放线菌剂和不施放线菌剂处理（浇灌放线菌剂和清水，灌根量均为0.8 g/株），槽式栽培，测定番茄植株生长指标、光合性能、PPO活性及PPO与光合指标的相关性。施菌处理均可促进番茄苗期叶长、叶宽、茎粗和株高的生长，且对连作4年土壤的促生作用最为明显；番茄叶片和根系的PPO活性随连作年限延长逐渐升高；在连作4年土壤中施用放线菌剂后，番茄苗期叶片叶绿素含量的菌剂效应最高，达10.78%，胞间CO2浓度在非连作土壤中提高3.48%；在连作土壤中，苗期番茄根系PPO活性与叶片PPO活性和叶绿素含量（P0.05）呈正相关，与叶片胞间CO2浓度、蒸腾速率（P0.01）和净光合速率呈负相关。放线菌剂对连作具有一定的改良作用：可以促进连作番茄苗期植株根系和地上部库源的生长，提高番茄PPO活性和叶片净光合速率，且以连作4年处理的促生效果最为显著，而对CO2的固定和利用过程没有作用。

إنجليزي. Through adding actinomycetes to potato different continuous cropping system soils, effects of continuous years on biomass and PPO activity were explored, which improves the reference for the effection of actinomycetes on continuous cropping tomato system soils. Tomato cv. “ Jinpeng No.1” was chosen as material, and non-continuous tomato soils out of greenhouse and continuous tomato cropping 4-and 8-year-system soils within the greenhouse as medium, making the treatments of adding actinomycetes and non-actinomycetes to research the growth promoting effect of actinomycetes on tomato plant regarding to biomass, PPO and the relation between PPO and photosynthetic index. All of the treatments with addition of actinomycetes improve the leaf area, stem diameter and plant height, especially in continuous 4 years soil. The PPO activity of tomato in leaf and root increases with the years of continuous cropped soils. Continuous cropping 4-year soil improves the actinomycetes effect of chlorophyll content on the tomato leaves up to the maximum at 10.78%, and intercellular CO2 concentration on tomato leave rises by 3.48% in non-continuous cropped soil. In the continuous cropped soils, the PPO activity of root has positive relation with the PPO activity of leaf and chlorophyll content (P0.05), whilst negative relation with the leaf intercellular CO2 concentration and transpiration rate (P0.01), as well as the net photosynthetic rate. Actinomycetes could improve the condition of continuous cropping tomato soils: actinomycetes can improve the growth of roots and aboveground parts, enhance induced PPO activity of leaves and roots of tomato during the vegetative period, and increase the net photosynthesis rate, especially significant in continuous 4 years soil, but have no effect to the process of CO2 settlement and use.