Studies On Mitochondrial And Chloroplast Genome Of Ulva Prolifera And Development Of Transcriptome-based SSR Molecular Markers

Green tide is a kind of ecological anomaly phenomena caused by largescale proliferation of seaweed.Since the the world-renowned algae bloom of Yellow Sea in 2008 Qingdao Olympic sailing regatta,more and more domestic and foreign scholars devoted themselves to the study of green tide algae in.At present,although the research on physiological and biochemical characteristics,life history,reproductive capacity and nutritional composition has completed a very comprehensive analysis and obtained abundant achievements.But the study of the organellar genome and transcription are relatively few.Based on the state of blank on studied of the chloroplast genome of Ulva prolifera——domain species caused the green tide algae boom,this study has finished the mitochondrial and chloroplast genome sequencing and analysis of Ulva prolifera,revealed the evolutionary relationships between the green tide algae.Analyzed the characteristics of the green tide algae by using the method of genome.And the same time,with the support of transcriptome data,development of SSR molecular markers are detected which laid the foundation of genetic relationship and genetic distance studies of green tide algae.Research results are as follows:1.Finishing the scequencing,assembling and analyzing of mitochondrial genome of Ulva prolifera The size of mitochondrial genome of Ulva prolifera 61962 bp,with the structure of single circular DNA molecules.GC content is 33.9%,a total of 29 protein-coding genes,21 transfer RNA genes and 2 ribosomal RNA genes are found.Through the construction of phylogenetic tree analysis,the study illustrated the genetic relations of Ulva prolife.2.Finishing the scequencing,assembling and analyzing of chloroplast genome of Ulva prolifera This study completed the first manuscript of chloroplast genome of Ulva prolifera.The size of chloroplast genome is 93066 bp,with a double chain closed circular chloroplast DNA structure.lacking a reverse repeat area,thus the chloroplast genome of Ulva prolifera is not a typical structure of 4 sections of chloroplasts.The GC content of chloroplast genome of Ulva prolifera is 24.78%.It is containing 66 protein-coding genes,26 transfer RNA genes and 3 ribosomal RNA genes in it.Four introns were found in the chloroplast genome of Ulva prolifera,one is located in a t RNA genes,the other three are on the protein-coding genes.3.Finishing the development of SSR molecular markersBased on the transcriptome sequencing data(unpublished)of Ulva prolifera.9872 SSR molecular marker are are detected,with the average frequency of 9.03%.The most abundant was(AC/GT)n,(CCG/CGG)n,(AGC/CTG)n,(AAC/GTT)n,accounting for 39.50% of the total SSRs.A small amount of repeats were(ACT/AGT)n and(AAT/ATT)n.Obeying the principle of SSR primer design,we select the proper SSR primes and find the one with good Polymorphism after PCR.6 primers is going to be verified by using samples of Ulva prolifera from five different location.This study is important for analyzing genetic diversity,marker assisted selection,genetic linkage mapping of Ulva prolifera by using SSR molecular markers.