| Sugarcane is an important energy herbs and is the most important sugar crop. The contribution rate for science and technology of sugarcane variety improvement is as much as 60%. Thus, the study of genetic diversity in sugarcane germplasm resources is the basis for the selection of crossing parents and the cross scheme. The study of genetic diversity in sugarcane main varieties and domestic newly released varieties is the basis of regional variety distribution and subrogation. Besides, it is beneficial to setting down the future scheme of sugarcane cross breeding in our country. Thus, the study is significant in science and in practice. In this study, on the basis of primers screening and PCR protocol estiblishement, 20 SCoT primers with 18 basepairs long were used in the SCoT fingerprintint for 107 sugarcane clones, and the analysis of the genetic diversity information existed in these clones were conducted. The main conclusions are as follows:Firstly, the detection of 20 SCoT primers with 18 basepairs long have abundant polymorphisms. The total number of bands amplified in the tested materials were 176, among which 163 were polymorphic and the polymorphism percentage reached 92.85%, while the polymorphism ratio of 8 primers reached 100%. And the polymorphic information content (PIC) at between 0.783 ~ 0.907, the average of PIC was 0.861. From above, it is indicated that the SCoT was an efficient fingerprinting technology with adequate polymorphism.Secondly, the genetic diversity analysis of the tested 107 sugarcane clones successfully were successfully implemented, and 11,449 genetic similarity coefficients, which range from 0.375 to 0.881, were obtained, thus the measurement of the genetic similarity of the 107 sugarcane clones was achieved.Thirdly, cluster analysis and principal component analysis was carried out in the 107 sugarcane clones with SCoT fingerprinting method. At the genetic similarity coefficient of 0.674, 107 sugarcane clones could be divided into six groups of clones: Groupâ… , mainly the Q, Mintang,Yuegan series; Groupâ…¡, mainly the FN series; Groupâ…¢, mainly the Yacheng and part of the CP series; Groupâ…£, mainly the ROC, part of the CP and India Co series; Groupâ…¤, including two clones, ROC1 and Q162; and Groupsâ…¥including some Yuetang series and other series. Principal component analysis showed that 107 clones tested clones should be divided into two categories of germplasm, the domestic and imported germplasm, which demonstrated that the genetic basis between these two kinds of germplasm was to some extent great.The using of the domestic germplasm and the germplasm imported abroad in cross utilization is expected to significantly improve the genetic diversity among the hybridization lines.Fourly, the results of cluster analysis showed the main cultivars ROC22, ROC16 and ROC10, which taking about 80% of the total sugarcane cultivation areas in our country, were distrituted in Groupâ… , Groupâ…¡and Groupâ…£, respectively. The genetic similarity coefficients between ROC16 and ROC10, ROC22 and ROC10 and ROC22 and ROC16 were 0.449, 0.455 and 0.722, respectively. It indicated the genetic diversity of three"ROC"varieties was relatively abundant. It is beneficial to sugarcane industrial safety. Besides, the average genetic similarity coefficient in 22 tested varieties entried national variety regional test was 0.593 only. It indicated the genetic diversity of varieties bred and released domestic was relatively abundant.Fifthly, according to the different breeding institute, 107 sugarcane clones could be assorted into 11 main ie. FN, ROC, Guitang, Mintang, Yacheng, Yuetang, Q, CP, Brazil, India Co, Yunzhe and other miscellaneous series. The results of the genetic diversity analysis showed that the genetic diversity (h) among the above 12 series ranged from 0.1635 to 0.3619. The highest h was found in the other series (0.3619), subsequently the h of the ROC and CP series was 0.3496 and 0.3466, respectively, while the lowest h existed in Yunzhe series (0.1635). The genetic diversity between two different series was much bigger than that among the clones in a single series. The genetic diversity among all the 107 sugarcane clones (0.3656) was 1.01 times the genetic diversity among different series (0.3615), and 1.41 times the genetic diversity among the clones in a single series. It is can be deduced that the genetic diversity among the tested 107 sugarcane clones was mainly existing among the 11 different series. |
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