Objective To determine the reducing sugar content, vitamin C content, starch content, polyphenol oxidase activity, crude protein content, potassium, iron and zinc content of 30 potato varieties, and to comprehensively evaluate the quality of different potato varieties' tubers using principal component analysis and systematic cluster analysis, with a view to screening out processing varieties with good quality suitable for planting in the northern Xinjiang.

Methods Different potato varieties of resource tubers were used as test materials, and descriptive statistical analysis, correlation analysis, factor analysis and systematic cluster analysis were used to comprehensively evaluate each variety.

Results The quality indexes among 30 potato varieties varied greatly with highly significant differences,among which the variation of reducing sugar was larger with a coefficient of variation of 81.75%, followed by reducing ascorbic acid and starch content with 37.10% and 27.95%, respectively, while zinc content had the smallest coefficient of variation. The quality data were standardized for principal component analysis, and three representative principal components of reducing sugar, vitamin C and starch content were extracted, and the highest F1 score of potato varieties in comprehensive evaluation was XN5, indicating that its zinc content was higher; the highest F2 score was YunYuan 401, indicating that its starch content was higher; and the highest F3 score was LiYuan29, indicating that its potassium content was higher. The top 10 scores were: YunYa 401\,>\, LongYa 6\,>\, North 001\,>\, Ly 1520-9\,>\, XN 5\,>\, LongYa 25\,>\, JinTongYa 3\,>\, Dafeng 12\,>\, L1631-14\,>\, North 013.

Conclusion The 30 resources were clustered into four classes, of which XN5 was class Ⅰ, with higher iron and zinc contents, and North001 was class Ⅱ, with the highest starch content; Zhongyan 31, Zhongyan 25, and Beifang 015 were classified as class Ⅲ, which had lower trace element content, higher vitamin C content, and the rest of the indexes were at a medium level; the remaining 25 resources were categorized as class Ⅳ.