These results support the hypothesis that China was the secondary center of sweetpotato diversity and also showed that Guangdong was the earliest region where sweetpotato was introduced to China.

• 品种遗传变异的地区间差异比较表明，广东地区的地方品种遗传变异高于其余3省，并且达极显著差异水平，从分子水平揭示广东应是中国甘薯的最早引入地，并向周边省及内陆地区扩散。