Genetic diversity analysis of phenotypic traits of sweetpotato landraces germplasm resources in Jiangxi

【Objective】 This study analyzed genetic diversity of phenotypic traits of sweetpotato landraces germplasm resources in Jiangxi,so as to provide reference for the innovative utilization and genetic improvement of sweetpotato germplasm resources.【Method】 With the support of the Third National Campaign of Crop Germplasm Census and Collection,111 samples of sweetpotato landraces germplasm resources collected in Jiangxi were used as materials and their 22 phenotypic traits(14 quality traits and 8 quantitative traits) were determined for 2 consecutive years from 2019 to 2020 in Nanchang. The genetic variation analysis,correlation analysis,Ward method cluster analysis and comprehensive evaluation were conducted to evaluate genetic diversity of these sweetpotato germplasm resources in Jiangxi.【Result】 For most of the 111 sweetpotato landraces germplasm resources,the color of top bud were light green or green,the top leaf and complete leaf were of incised shape. The colors of top leaf and leaves were mostly green,the main leaf vein color,basic leaf vein color,petiole predominant color,basic petiole color and stem predominant color were mostly green. The plant type were mainly semi-erect. The storage root shape were elliptic or anomaly,the skin color of storage root was mostly pink,and the predominant flesh color were orange,light yellow,yellow or white. The Shannon-Wiener diversity index (H') of 14 quality traits ranged from 0.31 to 2.01,with an average of 1.20. The H' of storage root shape,predominant skin color and predominant flesh color were relatively high,higher than 1.50. And the H' of leaf color was the lowest. The coefficients of variation(CV) of 8 quantitative traits ranged from 12.15% to 60.56%. The CV of percentage of moderate root and root number per plant were relatively high,higher than 50.00%. The CV of diameter of stem was the lowest. Meanwhile,the H' of 8 quantitative traits ranged from 1.38 to 1.50,with an average of 1.43. The H' of percentage of big root was the largest and the H' of length between nodes was the least. Length of main vine was extremely significantly positively correlated with length between nodes(P<0.01,the same below),and diameter of stem was significantly positively correlated with number of base branches(P<0.05). Furthermore,percentage of big root was extremely significantly positively correlated with number of base branches,but extremely significantly negatively correlated with length between nodes,root number per plant and percentage of moderate root. Tested 111 sweetpotato landraces germplasm resources were divided into 4 groups which varied widely in traits under investigation. Three germplasms with elite comprehensive traits and one germplasm with high dry matter content were identified,which were Beiguan white-flesh sweetpotato,Shiyuan sweetpotato,Zhoushe yellow-flesh sweetpotato and Xiushui big white-flesh sweetpotato.【Conclusion】 The majority of phenotypic traits of sweetpotato andraces germplasm resources in Jiangxi have obvious variation and rich genetic diversity,especially the traits of storage root have great potential for genetic improvement. The genetic relationship among landraces germplasm resources of sweetpotato is uncorrelated with the geographical origin.