杨梅树体健康状态的量化指标评价

Quantitative evaluation indicators of Chinese bayberry tree health status

以健康、衰弱病和凋萎病的杨梅树为试材,测定不同状态树体的根系、叶片、花芽等组织中的过氧化氢酶(CAT)活性、过氧化氢(H_(2)O_(2))含量、脂质过氧化物(LPO)含量、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、脱氢抗坏血酸(DHA)含量等生理指标,以及叶片拟盘多毛孢(Pestalotiopsis versicolor)ITS序列(PvITS)相对表达量,经统计分析去掉异常值后,建立可用于评价树体健康状态的量化指标和参考阈值。结果表明,健康树的根CAT、根DHA、枝条SOD指标与其他两种树体间存在极显著性差异,辅助评价树体健康状态的参考阈值分别是:117.52~280.67 nmol·min^(-1)·g^(-1)、1.02~1.58μg·min^(-1)·g^(-1)、484.20~804.99 U·g^(-1);PvITS相对表达量评价健康、衰弱病、凋萎病的参考阈值分别是0.78~1.15、1.76~3.91、9.54~29.62。通过筛选不同健康状态间差异量化指标,并结合树体典型表现,可更准确判断树的健康状态,为客观评价树体状态和正确采用防治措施提供科学依据。

Taking the roots,leaves,branches,and buds of healthy,decline and twig blight disease Chinese bayberry trees as test materials,a large number of samples were used to determine the indexes such as catalase(CAT)activity,hydrogen peroxide(H_(2)O_(2))content,lipid peroxide(LPO)content,malondialdehyde(MDA)content,superoxide dismutase(SOD)activity,peroxidase(POD)activity,dehydroascorbic acid(DHA)content,and qRT-PCR was used to determine the relative expression of ITS sequence(PvITS)of Pestalotiopsis versicolor in leaves.After statistical analysis and removing the abnormal value,the quantitative index and reference threshold that can be used to evaluate the health status of trees were established.The threshold of healthy trees were root CAT 117.52-254.52 nmol·min^(-1)·g^(-1),root DHA 1.02-1.58μg·min^(-1)·g^(-1),and branches SOD 484.20-804.99 U·g^(-1).And the reference thresholds of the relative expression of PvITS in healthy,decline and twig blight trees were 0.78-1.15,1.76-3.91 and 9.54-29.62,respectively.Combined with the obvious performance of the tree,the tree health status could be accurately judged.