Analysis On Genetic Diversity In Shatian Pomelo

Shatian pomelo was produced in Shatian village Rongxian county Guangxi province originally with a culture history of two hundred years. At present, Shantian pomelo covers more than a half area in culture of pomelo. Shatian pomelo is a single embryo plant. In the course of culture, there emerge lots of mutant species at the reason of hybrid seedling and mutation in nature. Research on genetic diversity of Shatian pomelo is the foundation in evolation and utilitation of Shatian pomelo germplasm, which makes important sense in choice of good gene and new variety selection.In this study, SRAP, cpSSR and karyotype analysis was taken to analysis of genetic diversity in30Shatian pomelo germplasm.In SRAP molecular marker analysis,252bands were amplified with63pairs of polymorphic primers, about118of them were diversity bands and the rate of diversity was25-100%per pairs of polymorphic primers. The genetic similarity coefficient among the30Shatian pomelo varied from0.6to1.0, which can divided into11groups when the genetic similarity coefficient was0.93. The1th group have10Guangxi native Shatian pomelo,3mutant single plant suspected of Guangxi, Hejiang, Dongguaquan and Jiangjin pomelo; The2th group have5Chongqin native species; there only have one germplasm in other9groups. The result showed that genetic foundation is relatively narrow in Shatian pomelo.In cpSSR molecular marker analysis, no polymorphic bands were amplified with24pairs of primers in30Shatian pomelo. The reason maybe be in two points, one is30germplasm share the same haplotype and the other is the detected Locus is not enough.In karyotype analysis,30Shatian pomelo belonged metacentric and nearly mctacentric chromosomes and category1A and2A was the main karyotype. The varation of asymmetric coefficient ranged58.34%-65.44%, the average arm ratio between1.39-1.92and chromosome length ratio between1.53-2.88. The results from the evolution trend map of karyotype showed that Jiangjin gulaoqian and Taijitu shatian pomelo were more evolved than Zaoshu and Gulaoqian shatian pomelo. The results of cluster analysis indicated that the genetic distance among the30Shatian pomelo germplasm varied from0to1.7, which can divided into8categories when the genetic distance was0.55and most of germplasms were of Type â…¡ and type â…£. The minimum genetic distance (0.1) was between Zaoshu and Xiahelong Ahalian pomelo, Lingnan and Beipei shatian pomelo, Rongxian xiaogexing bianyi and Gongcheng shizi shatian pomelo and the maximum genetic distance (1.7) was between Rongxianbendi2, Xingping2and Rongxianbendi1Shatian pomelo. There have a large genetic distance beween Rongxianbendi2and other germplasm witch indicated that the karyotype of Rongxianbendi2occurred much aberrant change.These studies found that results of molecular markers and karyotype analysis can be mutal-authentication to certain degree. Totally, genetic foundation is relatively narrow in Shatian pomelo.