柑橘黄龙病菌PCR阳性病株空间分布格局与参数特征应用研究

为了揭示浙江柑橘黄龙病菌PCR阳性病株空间分布信息和染病特征,2017—2018年对7个柑橘黄龙病发生样地2 900株橘树进行黄龙病菌PCR检测,按10株1样方取得290组样本资料,应用聚集度指标法对其空间分布型进行数据测定,结果达到C>1、I>0、K>0、C_A>0、M^*/$\bar{x}为了揭示浙江柑橘黄龙病菌PCR阳性病株空间分布信息和染病特征,2017—2018年对7个柑橘黄龙病发生样地2 900株橘树进行黄龙病菌PCR检测,按10株1样方取得290组样本资料,应用聚集度指标法对其空间分布型进行数据测定,结果达到C1、I0、K0、C_A0、■,均为聚集分布格局,表明柑橘黄龙病菌PCR阳性病株田间分布趋向聚集分布。经Iwao的M~*-线性模型回归检验表明,柑橘黄龙病菌PCR阳性病株空间分布的基本成分是个体群,病株间相互吸引,表现有明显的发病中心;经Taylor的■幂法则模型检验分析表明,黄龙病菌阳性病株的空间分布具有密度依赖性,阳性病株密度越高越趋向聚集分布,即聚集强度随阳性率上升而增强。其理论抽样数模型为■及序贯抽样公式为T_n=1.6976/D■+0.9296/n]。应用这些参数特征对提高田间柑橘黄龙病早期预警效率和决策防控具有良好的指导意义。

Study on spatial distribution pattern and parameter characteristics of PCR positive strains of Citrus Huanglongbing

In order to reveal the spatial distribution and infection characteristics of PCR positive strains of Citrus Huanglongbing in Zhejiang Province, PCR method was used to sample and detect 2 900 orange trees scattered in 7 different locations where Citrus Huanglongbing occurred during the year 2017 and 2018. Ten strains were clustered as a group, 290 groups of sample data were obtained. The spatial distribution pattern of Citrus Huanglongbing was determined by aggregation index method. The results showed that C>1, I>0, K>0, C_A>0, M^*/$\bar{x}$>1, were aggregation distribution patterns, indicating that the distribution of Citrus Huanglongbing PCR-positive plants tended to aggregation distribution. The regression test of Iwao's M^*-$\bar{x}$ linear model indicated that the basic components of spatial distribution of Citrus Huanglongbing PCR-positive plants were individual groups. The PCR-positive plants attract to each other, thus making a clear distributive focus of diseases in the citrus orchard. The analysis of Taylor's V-$\bar{x}$ power law model showed the spatial distribution to be density-dependent, the higher the density of positive plants, the more tendency to aggregate distribution, meaning the intensity of aggregation increases with growing positive rate. The theoretical sampling model was N=1.962/D²1.6976/$\bar{x}$-0.9296], while the sequential sampling formula was T_n=1.6976/$D^{2}_{0}$+0.9296/n]. The application of these parameters was of great significance in improving monitoring efficiency and early-warning of Citrus Huanglongbing, as well as making control decisions.