Deep Sequencing And Phylogenetic Analysis Of The Semi-wild Soybean(Glycine Gracilis)

Semi-wild soybean (Glycine gracilis) has the most abundant form in Legume first appeared in the11th century B.C. Both cultivar-and wild-specific characters are observed in the semi-wild soybean as a result that it is still controversial on the phylogenetic relationship or origin of the semi-wild soybean. With the rapid development of highthroughput sequencing technology and the lower of the sequencing price, it is now possible to conduct the semi-wild soybean origin research based on genome level. Consider that there are many genome data on wild soybean and cultivated soybean in public database which laid the foundation for us to answer the question of semi-wild soybean origin, a semi-wild soybean (Maliaodou) from Zhejiang Province, the low Yangtze River was collected and deep sequenced using the next genereation sequencing technology in this study. Based on comparative genomics analysis combined with the achieved results of a wild soybean (Lanxi1) genome analysis in our laboratory before and all the soybean genome data in public data, We found that the semi-wild soybean has two distinct characters which are strong proof that the semi-wild soybean has a hybridization origin of domesticated and wild soybeans. Firstly, its extreme high heterozygous rates (49%) was observed. Secondly, both cultivar-and wild-specific sequences were detected in the semi-wild soybean. The coverage rate is99.5%and12.1%respectively.In order to find out the potential parental lines of the semi-wild soybean and the genome structure variation during the process of domestication, further analysis was achieved. The results indicate that the wild parental line of Maliaodou might come from Huanghai valleys or regions along the Yellow River of China where the domesticated soybean has been suggested to originate in some literature. Besides, most of domesticated regions have been kept in the semi-wild soybean genome although many genomic rearrangements of the seimi-wild soybean occurred after the hybridization event which demonstrate that human activities, environment make weak impact on semi-wild soybean genome. Based on the analysis we found that the wild soybean and semi-wild soybean hold the abundant genetic diversity resource.This study confirmed the hybrid origin theory of the semi-wild soybean using bioinformatics method from the genome level. At the same time, the specific resource detection of cultivated soybean and wild soybean provides important information for future genetic breeding, as well as important clues for comprehensive resolution to soybean evolution.