关键词: 生姜 , SRAP , 遗传多样性分析 , 起源

Abstract: 【Objective】Ginger is vegetatively asexual crop that owns lots of local varieties, and its biological characteristics have been verified in many aspects caused by climate change, natural and artificial selection for thousands of years. This study was conducted to make a scientific classification of ginger germplasm, provide evidence for germplasm collection, protection and innovation of ginger by investigating the genetic diversity and relationship.【Method】Good genomic DNA was extracted from young leaves of 51 ginger accessions from different areas of the world following the CTAB method, and then were amplified by sequence-related amplified polymorphism molecular markers to analyze genetic diversity and phylogenetic relationship. Separation of the amplified fragments was performed on 6% denaturing polyacrylamide gels, The gels were stained with AgNO3 for visualizing the SRAP fragments, and then“0, 1” matrix was obtained according to the electrophoresis results. The number of polymorphic loci, percentage of polymorphic loci, effective number of alleles, Nei’s genetic similarity coefficient, genetic distance and the indexes of Nei’s genetic diversity and Shannon information were estimated by POPGENE version1.32. The cluster analysis of 51 ginger accessions based on unweighted pair-group method and 7 ginger populations based on Nei’s genetic distance were performed on NTSYS version2.10e to classify the ginger germplasm. Meanwhile, the origin and transmission of ginger were discussed in accordance with genetic diversity and phylogenetic relationship of ginger germplasm in different ecotopes and in light of the relevant characteristics of origin center and historical records.【Result】Among the 305 bands detected by 15 selective primer pairs, 188 (61.68%) were polymorphic. On average, each primer combination amplified 20.33 loci and 12.53 polymorphic loci. This showed that genetic variation of ginger is extensive. The average indexes of Nei’s genetic diversity and Shannon information were 0.3689 and 0.5510, respectively. Ginger germplasms were divided into 3 groups and 9 subgroups accordingly. Through comparative analysis, it was found that the same group gingers were from the same or similar region. Further analysis showed that ginger populations were separated into seven groups by geographical distribution, whose Shannon information index ranged from 0.2901 to 0.4807. The seven geographical populations were divided into 4 groups when the genetic similarity coefficient was set at 0.9. The Northern China population and Africa population formed their own group, respectively; Southeast Asia population, the Japan and Korea population formed a group; the coastal Southeastern China population, Southwest Plateau population and Central China population fell into another group.【Conclusion】 Analysis of 51 ginger accessions based on the indexes of Nei’s genetic diversity and Shannon information showed that genetic diversity of ginger was abundant though it is an asexual crop. The cluster analysis conducted with UPGMA of 51 ginger accessions based on genetic diversity coefficient indicated that genetic diversity of ginger germplasm was greatly influenced by geographical origins. Analysis on populations’ genetic diversity showed that genetic diversity of domestic populations in China was higher compared with foreign populations, in particular, Northern China population was far from other populations, moreover where the ginger cultivation has a long history, so the Northern China could be determined as the secondary center of origin; Africa is likely one of the native origin of gingers besides Southeast Asia, as the Africa population not only has a higher genetic diversity index, is far from other populations, and its space distribution is near from geometry center, but Africa also has wild species.

Key words: ginger (Zingiber officinale Roscoe) , SRAP , genetic diversity , origin