Xuzhou Sweetpotato Research Center, Xuzhou Institute of Agricultural Sciences, Xuzhou, Jiangsu, China. Key Laboratory of Sweetpotato Biology and Genetic Breeding, Ministry of Agriculture, National Agricultural Experimental Station for Soil Quality, Xuzhou, Jiangsu, China. Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, Jiangsu, China. sishui lifeng food products Co., Ltd, Jining, China. Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Plant Science Research Center, Chinese Academy of Sciences, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China. Sishui County Agriculture and Rural Bureau, Jining, China. Xuzhou Sweetpotato Research Center, Xuzhou Institute of Agricultural Sciences, Xuzhou, Jiangsu, China. zhonghoutang@sina.com. Key Laboratory of Sweetpotato Biology and Genetic Breeding, Ministry of Agriculture, National Agricultural Experimental Station for Soil Quality, Xuzhou, Jiangsu, China. zhonghoutang@sina.com.