Genetic Diversity Of Sugarcane And Its Relatives By SRAP And TRAP Markers

Marker-assisted selection is an important method, which can accelerate the process and improve the efficiency of plants breeding. Research on sugarcane molecular genetic diversity is an important basic work for sugarcane molecular breeding. Both SRAP marker with its primers designed according to the sequences of ORFs and TRAP marker with its primers designed according to the sequences of functional genes are important methods for study of molecular genetic diversity. A total of 109 sugarcane and its relative materials were used for analysis of genetic diversity. Twelve SRAP primers were used for analysis of all plant materials and forteen TRAP primers were used only for analysis of 75 sugarcane modern clones. The information of genetic diversity on these sugarcane clones were obtained by combination of SRAP marker data and TRAP marker data via the methods of cluster a nalysis, principal component analysis and genetic similarity analysis and it resulted the quality and quantity evaluation of genetic diversity of these materials. The results will enlarge the genetic diversity of cross parents in breeding programs and will help to direct the selection of the cross parents and help to guidance the distribution of cultivars. Thus, the study has important theoretical and practical significance. The main results and main conclusions are as follows.First, twelve pairs of SRAP primer showed good polymorphism.The result showed that a total of 162 bands were scored with the 12 pairs of primed screened, of which 151 taking 93.21% in total were polymorphisms. The polymorphism information content (PIC) ranged from 0.8361 to 0.9215 in 109 materials and the average was 0.8666. The number of alleles per SRAP primer ranged from 8 to 17 and the average was 12.58.Second, genetic diversity of 109 sugarcane clones was investigated by using twelve pairs of SRAP primers and the genetic similarity index between each other in all sugarcane materials was obtained. The result showed that the genetic similarity index of 109 sugarcane clones and its related genera ranged from 0.5191 to 0.9847 and the quantitative analysis of genetic similarity was made in all tested materials. The 109 materials were divided into two types at GS 0.635. The materials in second type were clustered into 4 groups at GS 0.765. The results showed that some materials were abundant in the genetic similarity, and had wide genetic basis. The others had low genetic similarity.Third, forteen pairs of TRAP primers showed good polymorphism . The result showed that a total of 144 bands were scored with the forteen pairs of primed screened, of which 103 taking 70.10% in total were polymorphisms. The number of alleles per TRAP primer ranged from 3 to 13 and the average was 7.36. The polymorphism information content (PIC) ranged from 0.8361 to 0.9215 in 75 sugarcane clones and the average was 0.8421.Forth, genetic diversity of 75 sugarcane clones was investigated using forteen pairs of fluorescence TRAP primer and the genetic similarity index between each other in all sugarcane materials was obtained. The result showed that the genetic similarity index of 75 sugarcane clones ranged from 0.5138 to 0.9236 and the quantitative analysis of genetic similarity was made in all tested sugarcane clones. The results showed that some materials were abundant in the genetic similarity, and had wide genetic basis. The others had low genetic similarity. The total of 75 sugarcane clones was divided into two types at GS 0.667. The materials in second type were clustered into 7 groups at GS 0.752.Fifth, the information of genetic diversity on 75 sugarcane clones was obtained by combinding SRAP marker data and TRAP marker data. The figures of cluster analysis, principal component analysis and genetic similarity analysis on these materials were obtained.