The Wild Germplasm Resources Evaluation And Core Collection Establishment Of Rosa Rugosa

As a rare and endangered plant,the wild rugged rose?Rosa rugosa;family Rosaceae?distributes in Jilin Tumen River Estuary,the south coast of Liaoning,and the coastal area of Shandong.The wild rugged rose possesses many desirable traits including strong fragrance and resistance to cold,drought,and other challenging environmental conditions.As wild rugged rose is hardier than most cultivated roses,its germplasm is an important resource for rose cultivation.This species is also important ecologically,as it can grow on sandy substrates and thus protect delicate costal areas from erosion.However,in recent years,many of the coastal areas that comprise the endemic habitat of the wild rugged rose have been subject to increasing industrial development,tourism,aquaculture,and other detrimental human activities,resulting in a decrease in suitable habitats.In order to better protect and utilize wild rugged rose germplasm resources,genetic diversity analysis and core collection of wild rugged rose were carried out using CDDP molecular markers,which provided theoretical basis for further research.The main achievements as followed:?1?DNA isolation of wild rugged rose species is difficult for their high content of polyphenol and polysaccharide.Here a modified CTAB method for wild rugged rose DNA extraction was presented.Through to extend the time of water-bath,appropriate adjustment of chloroform isoamyl alcohol?24:1?extraction times and a series of methods to improve the quality of its extraction.?2?Based on the results of orthogonal experimental design,the best 20ul system was established and optimized:2×Es Taq Master Mix?dyed?10 ul,10 pmol/ul primer 1.0 ul,40ng/ul DNA template 1ul and ddH₂O 8ul.Further researches on its stability and repeatability resulted that the system could be used for the genetic relationships analysis of wild rugged rose and so on.?3?In the present study,a set of 21 CDDP primers were used for genetic variability and diversity analysis among 120 wild rugged rose accessions.Only 13 primers that exhibited distinct and reproducible band patterns were selected for further analysis.?4?13 primers generated a total of 128 fragments with a mean of 9.84,ranging from 6?primer 7?to 14?primer 14?per primer.Of 128 band,121 bands?94.53%?were polymorphic.6-14 polymorphic bands were amplified by each primer,with an average of 9.23 polymorphic bands per primer.Detected polymorphism per primer among the tested accessions ranged from 77.78%?primer 4?to 100.00%,with an average of 93.75%;specific bands 8,compared with 6.25%.These results indicated that certain DNA polymorphism could be detected among wild rugged rose ermplasm using CDDP markers.In addition,the mean value of effective number of alleles?Ne?,Nei's genetic diversity?H?and Shannon information index?I?were respectively for 1.5131,0.3057 and 0.4646.All these calculated indices confirm that there is abundant genetic diversity in wild rugged rose.?5?At the population level,the genetic diversity index of population is highest in Hunchun,Chengshan minimum.Therefore,the genetic diversity of Hunchun population in Northeast China is the highest.?6?The core collection was established by using stepwise UPGMA clustering sampling approach.The 26 core collection resources of wild rugged rose collections in china have 20%germplasm samples of initial collection,the retention ratio of polymorphic loci,effective number of alleles?Ne?,Nei's genetic diversity?H?and Shannon information index?I?were respectively for 97.52%,104.16%,108.38%and 106.18%.The results of t-test showed that no significant different was found in genetic diversity indexes between the core collection and original collection.And these results demonstrated that the core collection could stand for original collection excellently.