重茬土壤、枯叶腐解液对广藿香扦插苗生理生化指标的影响

Effect of Continuous Cropping Soil and Decomposed Liquid of Dead Leaves on Physiological and Biochemical Indexes of Pogostemon cablin Cutting Seedlings

为了研究和探讨广藿香连作障碍成因及其作用机制,以广藿香扦插苗(2、8周龄苗)为试材,采用盆栽试验法,研究了广藿香重茬土壤、枯叶腐解液对其扦插苗叶片生理生化指标的影响。结果表明:2、8周苗龄广藿香扦插苗培育在广藿香重茬土壤和含不同浓度的枯叶腐解液的培养基质中60d,叶片过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性均较对照土呈升高的变化趋势,且随枯叶腐解液浓度的增加而升高,2、8周幼苗叶片CAT、POD、SOD活性均呈含高浓度枯叶腐解液的土壤>重茬土>含低浓度枯叶腐解液的土壤>对照土的变化规律;丙二醛(MDA)含量也较对照土显著升高,呈含高浓度枯叶腐解液的土壤>含低浓度枯叶腐解液的土壤>重茬土>对照土的变化规律。广藿香植株枯叶腐解物导致的化感自毒作用可能是其连作障碍的主要因素之一。

In order to study the causes and mechanism of continuous cropping obstacle in Pogostemon cablin, the pot experiment method was used to study the effect of physiological and biochemical indexes in its 2 and 8 weeks cutting seedlings cultured in cultivation substrate containing continuous cropping soil and decomposed liquid of dead leaves.The results showed that 2 and 8 weeks cutting seedlings cultured in cultivation substrate containing continuous cropping soil and decomposed liquid of dead leaves for 60 days，the activities of CAT，POD and SOD showed risen change in the leaves of the two cutting seedlings compared with that of the control，and raised with the concentration of decomposed liquid of dead leaves.The activities of CAT，POD and SOD in the leaves of two cutting seedlings showed the change in which the soil containing high concentration decomposed liquid of dead leaves〉continuous cropping soil〉soil containing low concentration decomposed liquid of dead leaves〉control soil.The content of MDA significantly increased compared with that of the control，and showed the change in which the soil containing high concentration decomposed liquid of dead leaves〉soil containing low concentration decomposed liquid of dead leaves〉continuous cropping soil〉control soil.Allelopathic autotoxicity caused by decomsosition of dead leaves in Pogostemon cablin might be the one of the main factors causing contiuous cropping obstacle.