Development Of Genomic SSR Makers Of Cinnamomum Camphora(L.)Presl

Cinnamomum camphora,belonging to the lauraceae family,distributes mainly in southern China.So far,there has been no reports about simple sequence repeats(SSR)markers from the genome of C.camphor.Accroding to the whole-genome sequence of C.camphor,we develop a set of SSR markers and some are selected at random to detecte polymorphism and transferability in species of the lauraceae family in this reserach.The main results are as follows:1.Analysis of SSR loci,frequency and motifs within the C.camphor genome.Total of114,774 SSR loci are identified by the MISA software,including 1 to 6 repeated units and beening about 1 locus per 350bp in the geome.Mononucleotide and trinucleotide repeats are two major types of G-SSR,accounting for 55.93%and 32.19%respectively.The dominating motifs are A/T(accounting for 97.34%)in mononucleotide repeats and(AG)_n(68.26%)in trinucleotide repeats.7193 pairs of SSR primers were obtained.2.Detection of polymorphism and genetic diversity in camphor trees by the SSR marekers.200 pairs of SSR primers are randomly selected to detected the polymorphism within smaller samples.The results showed that 61 pairs of primers amplified bands diversity and the 27 excellent pairs of them are screened out to detect the genetic diversity of three ancient camphor groups.Total of 115 alleles have been found from the 27 SSR sites and the equivalent of average 4.2593 alleles are identified per site.Effective number of alleles(ne)is 83.9 and the average is 3.1075 per locus.The average of expected heterozygosity(He),observed heterozygosity(Ho)and Nei's is 0.5370,0.6664 and 0.6582,respectively.Independently developed a number of camphor genomic SSR markers.3.The 27 SSR markers are tested to detect transferability in other species of the lauraceae family.In six species of Sect.Camphora(Trew)Meissn,the transferability rate is 100%but the rate is only 51.85%in four species of Sect.Cinnamomum.Meanwhile,the transferability rate are 29.63%and 33.33%in five species of Phoebe Nees and Machilus,respectively.This study gives a new way in the development of SSR in other species of Lauraceae.