Polymorphism Analysis And SRAP Primer Screening Of Genetic Map Construction In Tartary Buckwheat

Buckwheat of Polygonaceae is a dicotyledon, which grows in cold climate in China.It is a miscellaneous grain crops with high pharmaceutical and edible values.The evaluation of genetic background of germplasm is an essential step in plant breeding program. Most of reported researches about genetic diversity of buckwheat were carried out from traditional morphologic facet, isoenzyme analysis,or inter-species hybridize.However, there is lack of genetic diversity analysis based in molecular markers.Healthy food is receiving more and more attentions nowadays,so a fast and effective molecular marker used in buckwheat is needed. Sequence-related amplified polymorphism (SRAP) is a new molecular marker, has been successfully used for comparative genomics analysis,gene marker of important characters, evaluating of genetic diversity and map construction and so on in many plants.This study investigated the buckwheat in SRAP and SSR. The main results are as follows:The results indicated that the optimized SRAP reaction system for buckwheat was 0.2mM dNTPs,2.0mM Mg2+,30ng DNA,0.15μM of primer and Taq polymerase 1.0 U in the reaction of 20μl.The 10 accessions of buckwheat were analysed using 30 primer combinations,and the results showed 26 could amplify clearly and consistently. They produced a total of 285 fragments,of which 235 (82.5%) were polymorphic bands.5 could discriminate all the genotypes used in this study, among the 26 primer combinations.The genetic similarity coefficients varied from 0.6105 to 0.7825,based on the molecular data. The 10 accessions were better to be grouped into two major clusters at the similarity levels of 0.69.And the accessions got from the same province turned out being grouped in the same cluster, which indicated some geographical relationships. The cross of Fenghuang and Ye were analyzed in 103 pairs of primers, and 46 primers can be used to construct genetic maps of the buckwheat, accounting for 44.5%.This could provide a foundation for genetic map construction.Genome DNA extraction methods on the 2% CTAB,3% CTAB,kit were compared, and the results showed that the kit was better than the other two methods.In addition, we developed and screened the SSR primers of the buckwheat,24 clone products obtained were found small, short repeats as polymorphic SSR markers and could not be designed primers.3 polymorphic primers among 127 pairs of SSR primers were screened out, the ratio was relatively low, The result maybe that buckwheat lacks hybridization breeding for that it is a predominantly self-pollinated species and it is difficult to cross the tiny flowers (2-3mm) and obtain crossed seeds.It is difficult for buckwheat to analyze genetic diversity.