Study On Sampling Strategy Of Chimonobambusa Utilis Based On Genetic Diversity

Chimonobambusa utilis belongs to the subfamily Bamboo,which is an important unique bamboo speciesin southwest China.However,its genetic resourceswere still unknown.It is the basis of the study on population genetics to make scientific sampling strategy.In this study 13 ISSR markerswere usedto discuss the genetic diversity,genetic distance,cloning scale and spatial distribution pattern of two representative populations of Chimonobambusa utilis,and a reasonable sampling strategy was worked out.It canprovide important theoretical support for the collection,protection and utilization of the genetic resources of Chimonobambusa utilis,as well as for the study of the population genetics of related species.The main findings were as follows:(1)The genetic diversity of Chimonobambusa utiliswas low,and the genetic variation was mainly founded in the population.There were 16 polymorphic bands amplified by 13 ISSR primers.The percentage of polymorphic loci was 13.33 hannon information index 0.0391,andthe gene differentiation coefficient Gst was 0.0915.There was a certain gene flow between populations,which may be related to its large area blooming in history and local residents' intended artificial seedling supplement.(2)The clonal diversity of Chimonobambusa utilis level was higher.Shixi populations and Huanglian populations were polyclonal configurations,andthey identified 15 and 22 genotypes respectively.The genetic similarity coefficient of Nei's between genotypes varied from 0.9 to 0.9917 and the genetic distance was between 0.0084 and 0.1054;At the species level,the average scale Nc ofChimonobambusa utiliswas 5.33.Ratio of genotype PD was 0.23.Simpson diversity index D was 0.96.Fager evenness index E was 0.94.Chimonobambusa utilis clonal architecture was guerrilla type,the far extension distance was 141.4 2 meters,the clones of the two populations were in a chain like staggered distribution,which was closely related to the complex-axis mixed-type small-diameter bamboo.(3)The reasonable sampling distance between individuals was 45 meters.The spatial autocorrelation analysis showed that there were aggregation patterns in Huanglian and Shixi populations in small scale,and the average size of irregular clones was 41.024 meters and 56.475 meters respectively.The intercept of X axis at the species level was 44.728 meters,which indicated that the average size of irregular clone of Chimonobambusa utilis at the species level was about 45 meters.(4)When the sampling number was between 20-30,the percentage of polymorphic loci(PPB),expected heterozygosity(He)and the shannon polymorphism information index(I)of the sample population were all over 95%.Because it is a facultative clone plant,in order to contain as much genetic variation as possible,it is suggested that the reasonable sample size of population genetics of Chimonobambusa utilis should be set at 30.