| Obstacles to continuous cropping are a major problem for potato production.Allelopathy of phenolic acids is one of the main causes of continuous cropping obstacles.The autotoxicity of phenolic acids secreted from the plant roots in continuous cropping of potatoes results in serious reduction in potato production..Therefore,taking measures to reduce the concentration of phenolic acids in the soil of potato continuous cropping can also reduce the autotoxicity of phenolic acids,thus slowing down the continuous cropping obstacles;this study used the potato variety Chuanyu 117 as experimental material and adopted a two-factor randomized block design.Investigate the effects of organic carbon fertilizer on potato growth,yield,physiological and biochemical characteristics,soil enzyme activity and soil total phenolic content under phenolic acid stress in order to provide a theoretical bas is for solving potato continuous cropping obstacles.The main results of the study are as follows:1.Under the concentration of phenolic acid,low phenolic acid concentration of50mg/kg promoted the growth of plant height and stem diameter and the increase o f leaf area at each growth stage of potato plants,such as plant height,stem diameter and leaf area of potato plants at budding stage.The control 0mg/kg increased by 1.59%,9.69%and 10.34%respectively,which accelerated the dry matter accumulation of t he potato plants in the initial stage of growth,laid the foundation for the later growth of the potato,and promoted the increase of potato yield;with the phenol With the increase of acid concentration,the growth of the above-ground part of the potato was inhibited and the underground root volume was increased.At the ripening stage,the root volume at the 150 mg/kg high phenolic acid concentration was increased by50.10%compared with the control 0 mg/kg,and the dry matter mass was increased,and the root/shoot ratio was increased.Increased potato growth was inhibited and yields decreased.The activities of stress enzymes in potato leaves under 50mg/kg phenolic acid concentration were reduced.For example,the activities of SOD,CAT and POD in potato leaves at the bud stage were lower than the control 0mg/kg by6.95%,15.36%and 2.42%,respectively.Plasma membrane peroxidation was reduced,membrane permeability was not significantly different from control,antioxidant defense system was not responded,no adverse physiology was generated;antioxidant activity was increased with the increase of phenolic acid concentration,active radical scavenging,antioxidant defenses were eliminated.The system responds;the membrane permeability increases,the synthesis of soluble proteins and soluble sugars in the cell osmoregulatory substances increases,the concentration of intracellular solute increases,the osmotic potential decreases,and the membrane structure is maintained stable,thereby reducing the toxicity of phenolic acids to potato plants.effect.The application of phenolic acid can increase the activity of catalase in the soil at the initial stage of potato growth.As the phenolic acid concentration increases,the activity of urease,sucrase and acid pho sphatase decreases,and the activity of polyphenol oxidase increases.The activity of FDA hydrolase is not affected.The effect of phenolic acid concentration,such as urease,invertase and acid phosphatase activity in the rhizosphere soil at the 150 mg/kg high phenolic acid concentration,was reduced by 55.29%,46.17%,and 11.94%,respectively,compared to the control 0mg/kg.Inhibiting the increase of soil fertility by soil enzymes affects the absorption efficiency of soil nutrients by plant roots.The application of exogenous phenolic acids increased the total amount of phenolic acids in the soil of potato seedlings and inhibited the growth of potato in the early stage.2.Organic carbon fertilizer promoted the growth and dry matter accumulation of various organs of potato plants.The output of 450kg/hm~2 was the highest,and the harvest index was the highest,which was 24.59%and 7.80%higher than the control0kg/hm~2.Organic carbon fertilizer reduced the activities of antioxidant enzymes in potato leaves.During the budding stage,the leaf membrane permeability of potato plants at 675 kg/hm~2 increased by 28.60%compared with the control 0 kg/hm~2.Excessive application of organic carbon fertilizer increased the membrane permeability of potato leaves.The imbalance of membrane internal and external environment and the loss of intracellular soluble substances are not conducive to the growth and development of potato plants.Organic carbon fertilizer increased the activities of catalase and acid phosphatase in the soil,and the activity of urease and invertase decreased.The activity of urease and sucrase in the rhizosphere soil at the seedling stage was reduced by 33.68%compared with 0 kg/hm~2 in the amount of 225kg/hm~2.And 19.40%,which is related to the organic carbon fertilizer is rich in humic acid;appropriate amount of organic carbon fertilizer can promote FDA hydrolase and polyphenol oxidase activity.The organic carbon fertilizer promoted the growth of potato plants,increased their growth and metabolism,accelerated the secretion rate of phenolic acids in roots,and increased the total amount of phenolic acids in soil.3.Under the interaction of organic carbon fertilizer and phenolic acid concentration,the application of organic carbon fertilizer under high phenolic acid stress at 150 mg/kg resulted in an increase in plant height,stem diameter and leaf area of mature potato plants compared with A4B1(150,0)treatment.29.92%,1.92%and22.18%,the aboveground parts of potato plants showed a promoting effect,leaf area increased,vegetative growth and assimilation increased,and the dry matter quality of plant organs increased during the later growth period.The average dry matter quality of potato plants in mature stage was higher than that of A4B1(The 150,0)treatment decreased by 3.28%,the root to shoot ratio decreased,the yield increased,the phenolic stress stress improved,and the organic carbon fertilizer promoted the normal growth of the potato.The application of organic carbon fertilizer under high phenolic acid stress at 150mg/kg resulted in an average of SOD,CAT,and POD activities in potato leaves at the budding stage that was 6.15%,18.75%,and 15.91%lower than that of A4B1(150,0)treatment.,Antioxidant enzyme activity decreased,plasma membrane peroxidation weakened,membrane permeability decreased,osmotic adjustment weakened,adverse physiology weakened.The average urease,sucrose and catalase activity in the rhizosphere soil of po tato plants increased by 40.48%,10.85%,and 81.82%,respectively,compared with A4B1(150,0)at the seedling stage,which increased urease activity in the early stage of potato growth.Activity of invertase,sucrose and hydrogen peroxide,and soil fertility were increased.The mean values of FDA hydrolase and polyphenol oxidase activity at seedling stage were increased by16.25%and 9.53%,respectively,compared with A4B1(150,0)treatment.Soil-environment was obtained.Improved potato growth was promoted.The soil environment of potato was improved,the growth cycle of potato was prolonged,the total root exudates were increased,and the total amount of phenolic acids in the soil was increased in the late growth stage of the potato.In general,the phenolic acid stress in the soil was alleviated. |
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