北京工业职业技术学院学报

为快速、无损判别多品种辣椒的氮胁迫程度，通过水培方式对6个品种、共计144株辣椒进行氮胁迫培育试验，测定各植株叶片的叶绿素荧光参数及叶绿素含量。采用皮尔逊相关分析法筛选与氮胁迫高度相关的荧光参数，利用K-means聚类算法对氮胁迫程度进行分类，并使用总氮含量和叶绿素含量对聚类结果进行验证。试验筛选出4个与氮胁迫呈极强相关的叶绿素荧光参数，并使用K-means算法将样本划分为正常胁迫、轻度胁迫、重度胁迫3类。3类样本的总氮含量、叶绿素a含量、叶绿素b含量呈显著梯度下降，符合植物氮胁迫生理规律。该方法可为多品种辣椒氮素营养诊断检测提供参考。

To rapidly and non-destructively determine the nitrogen stress levels of multiple pepper varieties, this study conducted a hydroponic nitrogen stress cultivation experiment on a total of 144 pepper plants of six varieties. The chlorophyll fluorescence parameters and chlorophyll contents of leaves of each plant were measured. Pearson correlation analysis was used to screen fluorescence parameters highly correlated with nitrogen stress; the K-means clustering algorithm was applied to classify the nitrogen stress levels, and total nitrogen content and chlorophyll contents were used to validate the clustering results. The experiment screened out four chlorophyll fluorescence parameters with extremely strong correlations with nitrogen stress, and the K-means algorithm was used to classify the samples into three categories: normal nitrogen supply, mild stress, and severe stress. The total nitrogen content, chlorophyll a content, and chlorophyll b content of the three categories showed significant gradient decreases, consistent with the physiological characteristics of plants under nitrogen stress. This method can provide a reference for nitrogen nutrition diagnosis and detection in multiple pepper varieties.