show Abstracthide AbstractThere are abundant mulberry germplasm resources in China. Ongoing collection and preservation have resulted in the establishment of mulberry germplasm resource nurseries with different ploidy levels in various regions to provide abundant materials for mulberry breeding. To better develop and utilise germplasm resources, the comparative evaluation of mulberry germplasm resources with different ploidy levels is an essential step. Here, the evaluation of photosynthetic capacity is an important aspect. To further analyse the differential mechanisms of photosynthesis between GS6 and GSY12, the microstructural features and transcriptional levels of GS6 and GSY12 were analysed.