Genetic Diversity Of Cultured And Wild Undaria Pinnatifida In Dalian Coast Using AFLP

Undaria pinnatifida is a wide temperature algae of large scale,rich in vitamin A and other nutrients,with high protein,low fat,high fiber,etc.Not only delicious,but also have high nutritional value and medicinal value and can be used for the comprehensive utilization of raw materials extracted alginate.In China,natural growth Undaria pinnatifida are mainly distributed in Zhoushan Islands and Shengsi Island,Zhejiang Province.Dalian and Qingdao as a major breeding base,the majority is used to grow algae are through the introduction or wild seed,which is bound to lead to genetic diversity declining.In recent years,Undaria pinnatifida market demand growing both at home and abroad,expanding the scope of application,showing that the huge market potential.But breeding basis work is very weak.Therefore,depth study of the genetic background of Undaria pinnatifida is imperative.AFLP technique was used to estimate genetic diversity of Undaria pinnatifida which belong to four populations,Fujiazhuang(FJZ) wild,Xinghai(XH) wild,Zhangzi Island(ZZD) wild and Lingshui(LS) cultured.The purpose is to provide theoretical basis for breeding and protection of idioplasm.120 individual from four Undaria pinnatifida popolations (30 individuals per populations) were analyzed using 5 AFLP primer combinations.By using Popgen32 program , the genetic diversity was estimated , genetic distance was calculated and phylogenetic tree was constructed by UPGMA.The results are as follows:Total 277 loci were amplified using 5 primer combinations,and 232 were polumorphic loci.On average,46.4 polumorphic loci were amplified by each combination.Among the four populations,ZZD has the highest percentage of polumorphic loci which is 73.28%,YZ has the lowest one which is 64.25%.The range of alteration of index Shannon is from 0.3594 to 0.3971,and the heterozygosity is from 0.2408 to 0.2711.The alteration law of two indexes was identical,and the result was also identical with the analysis of the percentage of polumorphic loci.It can be inferred the intra-populations genetic variation:ZZD is highest,YZ is lowest.The total Gst was 0.1651.It means 16.51% genetic variation found in groups,83.49% of variation exists in the group.The Gst ranged from 0.0917 to 0.1416,that demonstrate no significant genetic differentiation,most of the variation from the internal populations.Gene flow was from 4.9520~3.0303,which means there was a certain amount of gene flow among the four populations.Genetic distance ranged from 0.0532 to 0.0996,shows that genetic variation between populations is relatively small.Based on genetic distances,the phylogenetic tree using UPGMA shows that XH was closer to YZ,and they were clustered together as the first grope.ZZD was clustered into the second grope, the last one is FJZ.By analysis of genetic variation of the four populations of Undaria pinnatifida,we found that they all have a high level of genetic diversity.But compared with the wild populations,the diversity parameters of the cultured population has decreased.In order to protect the cultured population maintained at a relatively high level,effective measures should be taken to prevent the seedlings mixed with other populations.The results of this article lay the foundation for further study on the genetic background and improve idioplasm of Undaria pinnatifida.The result also indicated that AFLP has a much higher polymorphic banding patterns than RAPD,ISSR . AFLP is a high-performance,reliable tool for the analysis of the genetic diversity of Undaria pinnatifida.