木麻黄青枯病发生与土壤五种元素含量分析

Analysis of the Occurrence of Casuarina spp.Bacterial Wilt and the Contents of Five Elements in the Soil

为探究木麻黄(Casuarina spp.)青枯病发生与土壤元素含量的关系,本研究选取广东省潮州市饶平县大埕镇、湛江市吴川市塘尾镇和湛江市徐闻县前山镇的3个木麻黄人工林为研究对象,分别于样地采集木麻黄青枯病罹病植株和健康植株根区土壤,共54个土壤样品,并测定土壤中5种元素的含量。结果表明,木麻黄感染青枯病的土壤中5种元素含量均有不同程度的降低,土壤有效硅含量显著降低(P<0.05)。徐闻样地有效硅、有效锰和交换性钙含量显著低于吴川样地(P<0.05),吴川样地有效铁和交换性镁含量显著低于饶平样地(P<0.05)。通过与发病等级的相关性分析发现,有效硅(r=-0.896)、交换性镁(r=-0.949)和有效锰(r=-0.896)含量均与发病等级呈极显著负相关关系(P<0.01)。发病等级与土壤有效硅含量减少量显著负相关(P=0.048<0.05),相关系数绝对值为0.632,呈中度相关性。交换性钙、镁含量在部分样地下降显著(P<0.05),有效铁、锰含量下降不显著(P>0.05)。综上,木麻黄青枯病罹病植株根系土壤中有效硅、交换性钙、交换性镁、有效铁和有效锰含量均较健康植株低,且所有样地中罹病植株和健康植株根系土壤有效硅含量差异均显著;木麻黄根系土壤中有效硅、交换性镁和有效锰含量均与青枯病发病等级呈极显著负相关关系。

In order to investigate the relationship between the occurrence of Casuarina spp.bacterial wilt in forest and the contents of soil elements,this study selected diseased and healthy plants of Casuarina from Dacheng Town,Raoping County,Chaozhou City of Guangdong Province,Tangwei Town,Wuchuan City and Qianshan Town,Xuwen County of Zhanjiang City,54 soil samples were collected and measured the content of five elements in the soil.The results showed that after Casuarina was infected with bacterial wilt,the content of five elements in the soil was reduced to different degrees.The available silicon content in the soil was significantly reduced(P<0.05).The content of available silicon,effective manganese and exchangeable calcium in Xuwen was significantly lower than that in Wuchuan(P<0.05),and the content of effective iron and exchangeable magnesium in Wuchuan was significantly lower than that in Raoping(P<0.05).Through the correlation analysis with the disease degree,it was found that the content of available silicon(r=-0.896),exchangeable magnesium(r=-0.949),and effective manganese(r=-0.896)all had an extreme significant negative correlation with the disease degree(P<0.01).The disease degree is significantly negatively correlated with the reduction of soil available silicon content(P=0.048<0.05),the absolute value of the correlation coefficient is 0.632,showing a moderate correlation.The content of exchangeable calcium and magnesium decreased significantly in some areas(P<0.05),while the content of effective iron and manganese decreased insignificantly(P>0.05).In summary,the contents of available silicon,exchangeable calcium,exchangeable magnesium,available iron and available manganese in the root soil of the diseased plants of Casuarina are lower than those of healthy plants,and the available silicon content difference in the root soil between diseased plants and healthy plants in all sample plots was significant;the content of available silicon,exchangeable magnesium and available manganese in the root soil of Casuarina showed a very significant negative correlation with the disease degree of bacterial wilt.