Development Of SSR Markers And Construction Of Genetic Linkage Map In Faba Bean (Vicia Faba L.)

Faba bean (Vicia faba L.) is one of the most important food legume crop and also one of the oldesthuman cultivated crops. China is the largest producer in both planting area and production of faba beanglobally. Due to its effective nitrogen fixation and soil improvement abilities, faba bean becomes animportant crop in the structure adjustment of planting industry. In addition, because of its high protein,high starch, low lipid, easy to digest and absorb, faba bean provides an important source of protein andstarch for human diets and animal feeds in many countries and play an essential role in farming systemand industrial structure. However, the genetic researchs on faba bean domestic and overseas are laggingbehind other crops and the molecular markers assisted genetic studies on faba bean are still scare. Themain goal of this study was to construct SSR linkage map of faba bean using F2population, bydeveloping genomic SSR markers using magnetic beads enrichment method, and EST-SSR markersthrough screening faba bean, pea and lathyrus EST sequences within public domain databases.The main results in my study were summarized as follows:1. Vicia faba EST sequences were sourced from database. In total,5029ESTs were found andanalyzed. The most abundant SSRs within faba bean were trinucleotide repeats, accounting for44.1%.The total repeat unit numbers of SSR loci were sixty-three. AG, TC, AAG were the most common motif,accounting for16.1%. Finally, sixty-six primer pairs were successfully designed by using Primer3.0software. These primers were identified and characterized for size polymorphism on32genotypesoriginating from China and elsewhere. The results revealed that forty-five pairs of primers (68.2%)generated bands, and twenty-one of these primer pairs (31.8%) revealed polymorphism.2.10662primer pairs developed by using magnetic beads enrichment method were screenedthrough eight faba bean accessions,4297primer pairs displayed successfully amplification and the ratioof amplification primers was40.3%. Of which,1140were identified as polymorphismic and the ratio ofpolymorphism primers was26.5%. The common nucleotide repeat motifs were mononucleiotide repeat,dinucleiotide repeat and trinucleiotide repeat. The amplification ratio of primers of mononucleiotiderepeat type and trinucleiotide repeat type were higher than the ratio of dinucleiotide repeat type. Thenumbers of primers of other repeat types were few.3. Through the transferability analysis of399pea EST-SSR markers and300lathyrus EST-SSRmarkers in eight faba bean accessions, the results indicated transferability rate of pea EST-SSR markers(56.9%) was obviously higher than transferability rate of lathyrus EST-SSR markers (22.3%). Thetransferability rate of trinucleiotide repeat type and tetranucleotide repeat type were highest. Thetransferability rate of heaxanucleiotide repeat type was low. The transferability rate of dinucleiotiderepeat type and pentanucleiotide repeat type was lowest.4. The genetic map of faba bean was constructed with SSR markers using a population consistedof129F2individuals derived from the cross of91825and K1563. By screening11517SSR primersbetween parents,148primer pairs were detected polymorphic and used for F2population analysis. This SSR based genetic linkage map consisted of14linkage groups with127SSR markers. The map covers1588.3cM with an average genetic distance of12.5cM.27%(P≤0.05) markers were identified to havesegregation distortion, and6segregation distortion regions (SDRs) were identified.