| The diversity of germplasm resources is not only the basis of new variety breeding,but also the source of modern agricultural science and technological innovation.Coix(Coix lacryma-jobi,L.)has wide distribution,long cultivation history and various germplasm types in China,and is one kind of excellent gramineous crops for grain,medicine and feed.However,there are few researches on the genetic diversity of Coix.In this experiment,main agronomic characters and InDel molecular markers were used to study the genetic diversity of Coix germplasm.The main results are as follows:(1)20 main agronomic characters such as plant height,flowering stage and involucre color of Coix were considered in the statistical analysis,and the results demonstrated that there was a high genetic diversity among population materials.The variable coefficients of each character were between 9.2% and 55.0%,with an average of 26.96%,among which the involucre color was the highest and the growth period was the lowest;the diversity index(H’)varied from 4.74 to 5.15,with an average of 5.10,among which the number of tillers,flowering stage and growth period were the highest,and the number of stem nodes was the lowest.The results of the correlation analysis showed that there were significant(P<0.05)or very significant(P<0.01)correlations among 20 main agronomic characters.Four principal component factors were extracted by principal component analysis,and the cumulative contribution value was 67.436%.(2)According to the phenotypic characteristics of 20 main agronomic characters,the genetic relationships of population materials were classified.The results verified that all materials could be divided into two categories when the genetic distance was23.5,including 91 in group I and 83 in group II.Meanwhile,the genetic relationships of the population materials were clustered at the molecular level by using 220 pairs of InDel markers that evenly distributed in the whole Coix genome.When the genetic similarity coefficient was 0.567,174 Coix materials were also divided into two categories.Among them,there were 82 materials in group I and 92 materials in group II,and the genetic similarity coefficient was between 0.524 and 0.997.The phenotypic cluster result of most of the materials was consistent with the molecular cluster result.(3)18 pairs of InDel primers with good polymorphism were used and combined,resulting in distinguishing all the Coix materials precisely.The first InDel fingerprint of Coix materials was drawn by the 18 pairs of primers and the "1,0" data of the electrophoretic results of the tested materials,then 36-bit "1,0" binary code was transformed into a simple decimal code,giving each Coix material a unique "molecular identity". |
