Among the genus Actinidia, Actinidia arguta possesses the strongest cold resistance and produces fresh fruit with an intense flavor. To investigate genomic variation that may contribute to variation in phenotypic traits, we performed whole-genome re-sequencing of four A. arguta genotypes originating from different regions in China and identified the polymorphisms using InDel markers. In total,4,710,650,4,787,750,4,646,026,and 4,590,616 SNPs and 1,481,002,1,534,198,1,471,304,and 1,425,393 InDels were detected in the 'Ruby-3', 'Yongfeng male', 'Kuilv male', and 'Hongbei male' genomes, respectively, compared with the reference genome sequence of cv 'Hongyang'. A subset of 120 InDels were selected for re-sequencing validation. Additionally, genes related to non-synonymous SNPs and InDels in coding domain sequences were screened for functional analysis. The analysis of GO and KEGG showed that genes involved in cellular responses to water deprivation, sucrose transport, decreased oxygen levels and plant hormone signal transduction were significantly enriched in A. arguta. The results of this study provide insight into the genomic variation of kiwifruit and can inform future research on molecular breeding to improve cold resistance in kiwifruit. OPEN ACCESS Citation: Lin M, Fang J, Hu C, Qi X, Sun S, Chen J, et al. (2020) Genome-wide DNA polymorphisms in four Actinidia arguta genotypes based on wholegenome re-sequencing. PLoS ONE 15(4): e0219884. https://doi.org/10.regulated by CBF transcription factors. In a previous study, CBF was cloned from the fruit of kiwifruit plants, and the expression of CBF was found to be increased when fruit was stored at low temperatures [6]. Proteomics analysis showed differences in proteins involved in photosynthesis, sugar metabolism, gene regulation, signal transduction, and stress resistance under lowtemperature stress in A. arguta leaves [7]. Despite the extensive knowledge regarding the coldrelated changes in A. arguta, the genetic components underlying these differences remain poorly understood, and associated genomic information for this species is lacking.The basic chromosome number of kiwifruit (x = 29) is high compared with those of other horticultural crops, and the genus presents extensive inter-taxal and intra-taxal variations in ploidy [1]. The sequence of the kiwifruit variety cv 'Hongyang', which was the first species in Ericales to be sequenced, represents a valuable resource not only for biological discovery and crop improvement but also for evolutionary and comparative genomic analysis. The sequence assembly covers~80% of the estimated genome size of 758 Mb [8], and its annotation revealed 39,040 predicted genes [9]. The genome annotation data of cv 'Hongyang' were updated in 2015, including 20 genes that were revised and 30 genes that were created (http://bdg.hfut.edu. cn/kir/index.html). Mining of microRNAs in the cv 'Hongyang' genome and transcriptome has led to the identification of 58 putative microRNAs in kiwifruit [10]. Li utilized this genome sequence to profi...