Analysis of main quality traits of potato cultivars from different producing areas in China

【Objective】To comprehensively analyze the main quality traits of potato cultivars form different producing areas in China，and to provide reference for making breeding objectives and the utilization of germplasm resources. 【Method】The contents of dry matter，starch，total sugar，soluble sugar and reducing sugar in fresh potato were measured in tubers of 48 potato cultivars widely cultivated in different main producing areas，including northern，northwestern and southwestern China. The methods of correlation，principal component analysis，cluster analysis and genetic diversity were used to comprehensively analyze the quality traits of potato cultivars from different producing areas.【Result】The result showed that the dry matter content of 48 potato cultivars tubers ranged from 13.71% to 20.01%，with an average of 16.85%. The starch content ranged from 7.94% to 15.72%，with an average of 11.24%. Among them，the cultivars of Zhongshu 17，Zhongshu 5，Longshu 7 and Kennebec had higher content of dry matter and starch than others，which had the potential to be used as the special cultivars for processing whole flour or starch. The total sugar content of the 48 potato cultivars ranged from 55.25-287.70 mg/g，with an average of 140.10 mg/g；the soluble sugar content ranged from 2.60 to 26.78 mg/g，with an average of 7.81 mg/g；the reducing sugar ranged from 0.16 to 6.08 mg/g，with an average of 3.12 mg/g. Among them，the reducing sugar content of Yunshu 304，Zhongshu 16，Zhongshu 26，Atlantic（Shijiazhuang）and Zhongshu 18 were low. The quality traits of potato cultivars from different producing areas had some differences. For example，the cultivars from Zhangjiakou of Hebei Province and Lanzhou of Gansu Province had higher dry matter and starch contents；the cultivars from Kunming of Yunnan Province and Zhangjiakou of Hebei Province had lower reducing sugar content. Correlation analysis showed that dry matter content was extremely significantly positively correlated with starch content（P<0.01），and was significantly negatively correlated with total sugar content（P<0.05）. The 48 potato cultivars were divided into 3 categories based on cluster analysis. The first category contained Qingshu 168，HF-10，Lishu 10 and Longshu 7，which had higher dry matter，starch and total sugar contents；the second category contained Qingshu 6，Qingshu 9（Xining），Xiazhai 65，Lishu 6，Qingshu 10 and Leshu 1，which had lower total sugar content. The other cultivars had no obvious dominant trait characters. The genetic diversity indexes of 5 traits was 1.77-2.03. The starch content and total sugar content had the highest and lowest genetic diversity indexrespectively.【Conclusion】The overall level of dry matter and starch content of potato cultivars in China are relatively low，which still has great room for improvement. The reducing sugar content of nearly half of the cultivars meets the requirement of fried food production. Compared with starch and dry matter content，sugar content is more affected by cultivation environments and practices.