Humulus japonicas is dioecious plants with XX/XY1Y2 sex chromosome system,which is one of model materials for studying sex chromosome evolution.In this study,the single chromosome of Humulus japonicaswas microdissected and amplified from roots tip on mitosis metaphases.Then,the DOP-PCR products amplified from the single chromosome were labeled with Alexa Flour-488 by nick translation method and hybridized to the chromosomes of female Humulus japonicasplants.The fluorescence signals were distributed on all c...