论文部分内容阅读
为明确玉米秸秆腐解的化感物质对燕麦种子萌发及幼苗生长的影响,分别采用0.2、0.4、0.6、0.8和1.0 mmol·L~(-1)的邻苯二甲酸(PA)和对羟基苯甲酸(p-HBA)胁迫处理燕麦种属裸燕麦(Avena nuda)品种‘白燕2号’的种子,测定根系鲜重、幼芽鲜重、根长、超氧阴离子自由基(ROS)含量和丙二醛(MDA)含量,以及抗氧化系统活性。结果表明:随着化感物质PA和p-HBA处理浓度的增加,燕麦根系和幼芽的ROS含量逐渐增加,诱导超氧化物歧化酶(SOD)活性逐渐增强;而过氧化氢酶(CAT)活性的变化受PA和p-HBA浓度影响较为复杂;同时,ROS积累导致了过氧化物酶(POD)活性的提高。PA和p-HBA作用导致了燕麦幼苗的膜脂过氧化,处理浓度>0.6 mmol·L~(-1)幼芽的MDA含量显著增加;根长显著降低,根冠比达到最低值。PA和p-HBA对根系的抑制程度大于幼芽,且PA的抑制作用大于p-HBA,根系损伤是两种物质对燕麦化感效应的直接体现。
In order to clarify the effects of allelochemicals decomposed by corn stalks on the seed germination and seedling growth of oat, 0.2, 0.4, 0.6, 0.8 and 1.0 mmol·L -1 phthalic acid (PA) The root fresh weight, fresh weight, root length, superoxide anion free radical (ROS) content in the roots of Baiyan No.2, a type of Avena nuda, were treated with benzoic acid (p-HBA) And malondialdehyde (MDA) content, as well as antioxidant system activity. The results showed that with the increase of the concentration of PA and p-HBA, the ROS content in roots and buds of oat gradually increased, and the activity of induced superoxide dismutase (SOD) increased gradually; while the activities of catalase (CAT) The change of activity is more complicated by the concentrations of PA and p-HBA. Meanwhile, the accumulation of ROS leads to the increase of peroxidase (POD) activity. The action of PA and p-HBA resulted in membrane lipid peroxidation in oat seedlings. The content of MDA in shoots> 0.6 mmol·L -1 increased significantly, while the root length decreased significantly and the root / shoot ratio reached the lowest value. The inhibitory effect of PA and p-HBA on the root system was greater than on the shoots, and the inhibition of PA was greater than that of p-HBA. Root damage was the direct manifestation of the allelopathic effects of both substances on oats.