Abstract: The tuber bruises can be alleviated by breeding new cultivar, improved agronomy and enhanced germplasm based on understanding the key factors affecting bruises. In this research, the cultivars (clones) with prominent difference in bruises, Desiree, Russet Burbank, Chunshu No.4, 9637-83 and TD38-2 were chosen as experimental materials. Data were taken for skinning(SK), internal bruise(IB), and browning(BR), as well as for 17 tuber indexes. Correlation analysis was made, and then partial least-squares regression(PLSR) regression model was established after PLSR analysis. Based on the model, tuber indexes measured had similar impact on both skin bruise and internal damage, but not for discoloration. However, Ca²⁺, Tyr and Chloregenic acid had remarkable effects on all bruise variables, positively or negatively. It was shown that this model in the research had more advantages, such as stronger integrity, reasonable conclusion, easily explainable regressive parameter, so that it can be uesd in scientific reaearch and production reliably.

Key words: potato, tuber, bruises, partial least-squares regression(PLSR)