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为明确辣椒(Capsicum annuum L.)根系分泌的潜在化感物质对生菜幼苗抗氧化特性及矿质养分吸收的影响,分别采用5、10、15、20和25μg·m L~(-1)的N-苯基-2-萘胺(P2NA)和邻苯二甲酸(PA)与Hoagland营养液混合胁迫处理生菜幼苗,测定抗氧化酶活性、渗透调节物质浓度和矿质养分含量,以期丰富辣椒根系分泌物化感机制研究。结果表明:与营养液对照比较,P2NA、PA,以及两者的混合处理在0~15μg·m L~(-1)浓度范围内,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性增强,谷胱甘肽(GSH)和游离脯氨酸(Fpro)含量增加,活性氧自由基(ROS)和丙二醛(MDA)含量降低;处理浓度达到20μg·m L~(-1)以上,ROS含量增加,抗氧化酶系活性和GSH含量显著降低,膜脂过氧化程度提高;潜在化感物质作用下,生菜幼苗的抗坏血酸氧化酶(AAO)活性降低,氮、磷、钾大量元素积累量均不同程度降低,钙和镁含量随着处理浓度增加先升后降,峰值处理浓度分别为10和15μg·m L~(-1)。10μg·m L~(-1)的P2NA和PA处理最适于生菜幼苗抗逆能力的提高,浓度>15μg·m L~(-1)则因ROS积累,尤其是过氧化氢(H_2O_2)积累,造成膜脂过氧化程度加强,细胞渗透调节能力和矿质营养吸收能力降低,且P2NA的潜在化感作用强于PA,可能两者具有一定的互作效应。
In order to clarify the effects of potential allelochemicals secreted by root system of Capsicum annuum L. on antioxidant properties and mineral nutrient absorption of lettuce seedlings, the effects of 5, 10, 15, 20 and 25 μg · m L -1 N - Phenyl-2-naphthylamine (P2NA), Phthalate (PA) and Hoagland nutrient solution were used to treat lettuce seedlings. The activities of antioxidant enzymes, osmotic adjustment substances and mineral nutrients were determined to enrich the root exudation of pepper A sense of mechanism research. The results showed that compared with the nutrient solution control, the contents of P2NA, PA, and the mixture of the two treatments were in the range of 0 ~ 15μg · m L -1, the activities of superoxide dismutase (SOD), catalase ), POD activity increased, GSH and Fpro contents increased, reactive oxygen species (ROS) content and malondialdehyde (MDA) content decreased; the treatment concentration reached Above 20μg · m L -1, ROS content increased, antioxidant enzyme activity and GSH content decreased significantly, and membrane lipid peroxidation increased. Under the action of latent allelochemicals, the activity of ascorbate oxidase (AAO) The contents of N, P, K decreased to different degrees. The content of Ca and Mg increased first and then decreased with the increase of treatment concentration. The peak treatment concentrations were 10 and 15 μg · m L -1, respectively. P2NA and PA treated with 10μg · m L -1 were the most suitable for improving the resistance of lettuce seedlings. Concentration> 15μg · m L -1 was due to the accumulation of ROS, especially the accumulation of hydrogen peroxide (H 2 O 2) , Resulting in the enhancement of membrane lipid peroxidation, the ability of cell osmoregulation and mineral nutrient absorption, and the potential allelopathy of P2NA is stronger than that of PA, which may have some interaction effects.