Abstract: Using the medicinal plant Polygonatum sibiricum as an example, a karyotype analysis method and workflow for plant chromosomes was established based on the open-source image processing software ImageJ. The ImageJ software was opened, and the Stowers plugin package and LEVAN plugin were loaded. The acquired microscopic images of Polygonatum sibiricum metaphase chromosomes were processed through image preprocessing, chromosome contour selection, chromosome segmentation and debris removal, and chromosome cropping to obtain chromosome morphological data. Photoshop software was used for karyotype arrangement, and Excel software was used to draw the karyotype ideogram. The results showed that, according to Levan’s karyotype classification standard, the karyotype formula of Polygonatum sibiricum was 2n = 24 = 4m + 10sm + 10st, with an asymmetry index of 72.11%, belonging to the 3B type. This method proposed a solution strategy for chromosome contact or overlap in karyotype images, with the advantages of being open-source, free, having a clear operational workflow, and providing accurate interaction.

Key words: Polygonatum sibiricum, ImageJ, medicinal plants, chromosomes, karyotype analysis