Development Of DUS Test Guide For Coprimus Comatus

With the continuous development of the Coprinus comatus industry,the demand for new varieties is also increasing,but the variety is single,and the strain management is chaotic.In order to ensure the healthy development of C.comatus industry in China,it is necessary to strengthen the protection of new varieties.At present,there is also a lack of protection mechanism for new varieties of C.comatus,the international authority UPOV and its member countries have not issued the relevant documents of the C.comatus DUS test.Therefore,it is necessary to speed up the development of the C.comatus DUS test guidelines,so as to provide technical basis for intellectual property protection of new varieties of C.comatus.Total 39 strains of C.comatus germplasm were collected from different parts of China,including 24 cultivated germplasm and 15 wild strains,ISSR molecular markers were used to classify and identify germplasm resources and study their genetic diversity,conduct laboratory and field tests,the characteristics were observed and analyzed,the standard traits and varieties were screened out based on the analysis results of agronomic traits,and the DUS test guidelines were compiled.The main results were as follows:(1)Ten primers with clear and stable bands were screened by ISSR molecular markers,and their sizes ranged from 100 bp to 2000 bp.The results of clustering showed that the germplasm resources of C.comatus were rich in genetic diversity,the genetic similarity ranging from 0.54 to 1,the 39 strains were divided into 3 groups at the Euclidean distance of 0.61,the 39 strains were divided into 3 groups by principal co-ordinates analysis,the two analyses agree.The genetic distance between some cultivated strains was 0,and some strains were introduced to each other,indicating that ISSR molecular markers could be used for germplasm classification and identification.(2)Combined with laboratory and field experiments,17 traits were screened out for further observation,2 mycelium traits including colony density and pigmentation intensity,15 fruiting body traits including cap shape,the convex at the top of the pileus,numbers of pileus squama,pileus color,top color of pileus,secretions from the top of pileus,stipe shape,the inflate position of stipe,the relative position of the pileus to the stipe,harvest time,pileus length and width,fruiting body length,stipe diameter and stipe inflate diameter.(3)The pileus length and width,fruiting body length,stipe diameter and stipe inflate diameter of the tested strains rich in diversity,the variation range of 5quantitative traits was 15.44% ~ 26.23 %,each trait conforms to normal distribution or skewness distribution,according to probability grading method,it can be divided 3or 5 levels.(4)Correlation analysis results showed that,the correlation of 5 quantitative traits was significant or extremely significant;The cluster analysis of 17 agronomic traits of 39 tested strains was carried out,the Q-type cluster divided 39 tested strains into 5 groups at the Euclidean distance of 1.55,and the genetic distance of some strains was 0,indicating that Q-type cluster could be used for germplasm resource classification and identification,or for grouping traits,test traits and standard strains;The R-type cluster divided the 17 agronomic traits into two groups at 1.81 Euclidean distance,five quantitative traits were significantly correlated with each other,while the other traits were independent of each other;Principal component analysis,the relative position of the pileus and the stipe,stipe shape,inflate position of stipe,the convex at the top of the pileus,numbers of pileus squama were extracted and could be used as grouping characteristics,based on the principal component results,strains with high comprehensive scores were screened out and could be used as standard strains.(5)According to the general guidelines for testing consistency and stability of new plant varieties(GB/T 19557.1).Combined correlation test,16 traits(7quantitative traits and 9 pseudoquality traits)were screened as DUS test traits finally,including 2 mycelium traits and 14 fruiting body traits,five standard strains were screened,the text of "Guidelines for the conduct of test for distinctness,uniformity and stability,Coprinus comatus" was formed.