Fig. 1.

Geographical distribution and possible introduction routes. a Global distribution of the barley accessions. WGS whole genome sequencing accessions, ES exome sequencing accessions, Hsp H. spontaneum, Hag H. agriocrithon, TWB Tibetan weedy barley. The pentagram indicates the location of National Crop Genebank of China (NCGC), which provided 50 WGS barley cultivar accessions. b Distribution of qingke landrace and Tibetan weedy barleys in seven areas of Tibet. The seven areas are identified by different colors. c Possible introduction routes of qingke from Central Asia to Tibet. The nearby provinces (Qinghai, Gansu, Sichuan and Yunnan) of Tibet where Tibetans (Zang people) live are identified by different colors. The circle or ellipse indicates the location of the barley archaeological site, including Mijiaya¹⁸, northeastern Tibetan Plateau¹⁹, northeastern India²¹, and Changguogou²². The pentagram indicates the location of Ganzi, where ÅEberg discovered and described H. agriocrithon in 1938 for the first time⁸. The red dash line indicates the reported introduction route of wheat^13–17. The blue dash line (route I) indicates the introduction route of barley in North and Eastern China^13–19. The yellow dash line (route II) indicates the possible introduction route for qingke from Northern Tibet¹⁹. The magenta dash line (route III) indicates the new discovered route for introduction of qingke from south Asian reported in this study. a, b were generated in R (V3.4.3) using packages maps, maptools, plyr, ggrepel, and ggplot2. Geographic information data were obtained from Global Administrative Areas database (GADM V2.8, November 2015). The original map of c was from https://d-maps.com/carte.php?num_car = 11572&lang = en. Source data are provided as a Source Data file