| Rubia cordifolia L.is a perennial climbing herb belong to the family Rubiaceae.The chromosome number is 2n=22,x=11,diploid species.The ability of growing is stronger,Rubia cordifolia L.is a common harmful weed in the farmland,orchard,lawn and the botanical garden.It is not only affecting the ornamental value of gardening also affecting the economic output of crops seriously.Tribenuron-methyl is an inhibitor of ALS,it is widely used for controling weed.With the extensive using of chemical herbicides,some serious problems such as environment pollution and resistance are happening.Using SSR molecular markers to study the genetic diversity and genetic structure of Rubia cordifolia L..According to analysis the genetic relationship between different groups and evolutionary history,to reveal the population genetic differences between genetype level and the ability of adapting to the environment.The differences of genetic diversity between different population causing the differences of resistance level.It is important to master the relationship between genetic diversity of populations and the resistance level,to provide an important theoretical for the prevention and control of Rubia cordifolia L..The results of important research are as follows:（1）Using the magnetic beads enrichment method to build SSR microsatellite enrichment library which contains 557 cloned,selecting the PCR product of 118 cloned to sequence and gaining 94 effective monoclonal sequence.There is 52 sequences contains SSR,the yield is55.32%,every 883 base pairs have a SSR loci.Among the SSR repeat unit,three bases has 40 and is the most,76.92% of the total,the repeat unit of ATC,the CAG and AC are the most abundant;the imperfect type of SSR is 20（38.46%）,the perfect type is 23（44.23%）;the hybrid type is 9（17.31%）;the repetitions of SSR repeat unit are between 4-10 mostly,92.31%（48）of the total repeat unit.（2）Designing primers and then doing selection or optimization,there are 15 specific SSR primers in total.Using the 15 primers for 115 individual of seven populations to test STR.Analysis results show that Na is15.07;Ne is 6.36;Ho is 0.589;He is 0.621.HT is 0.626,Hs is0.586,DST is 0.04,the genetic diversity is higher;GST is 0.064,FST is 0.0960,Fis is-0.0352,Genetic differentiation between groups is small,Nm is 2.3544.（3）According to UPGMA,seven populations of Rubia cordifolia L.getting together for twobranches,the population of XM and ZM are in the same branch;the population of RZ,DF,JY,SX and BJ are in another branch.Structure has the same result with UPGMA.（4）TPM is between IAM and SMM,which is the common type of SSR.Using Bottleneck for analysising under the type of TPM,the results show that seven groups has not been experienced bottleneck,the groups have not undergone the resistance selection of herbicide in the genetic diversity study.Besides the historical influence of Tribenuron-methyl herbicide,the results of resistant levels can reflects the differences on the genetic level of genetic diversity directly.（5）Determination of resistance level,the resistance ratio of DF is 2.89.Determination the resistance level of SX,DF,ZM and XM populations,the EC50 of SX is 83.49 mg·L-1;the EC50 of DF is 100.77 mg·L-1;the EC50 of XM is 44.60 mg·L-1;the EC50 of ZM is 47.99 mg·L-1.The EC50 of XM and ZM are similar,and they are less than SX and DF;the He of XM is 0.54164,the He of ZM is 0.55329,they are inferior to SX（He is 0.59968）and BJ（He is 0.58747）;in this way we can know there are interrelated between genetic diversity and resistance level. |
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