【作者】 杨翠；

【导师】 许莉萍； 阙友雄；

【作者基本信息】 福建农林大学 ， 草业科学与技术， 2010， 硕士

【摘要】 甘蔗是我国重要的能源草本植物和最重要的糖料作物,甘蔗品种改良的科技贡献率高达60%,了解种质资源的遗传多样性是有助于指导杂交育种亲本选择和组合配置;了解我国甘蔗主要栽培品种和各育种单位新选育品种和高代品系的遗传相似性,对栽培品种的区域布局和更替以及有关单位后续杂交选育计划的制定,均具有重要的科学意义和应用价值。为此,本研究率先应用2009年国际最新开发的SCoT标记,在筛选多态性引物、建立PCR反应体系和程序的基础上,采用20条18碱基的SCoT引物,对107份甘蔗无性系进行SCoT标记,获得了这些甘蔗无性系的遗传多样性信息,主要结论如下:(1)利用20条18碱基的SCoT引物,对107份甘蔗无性系进行扩增,共扩增出176条条带,其中多态性条带163条,多态性百分比达到92.85%,有8条引物的多态性比率达到100%,多态信息量(PIC)在0.783~0.907之间,PIC平均值为0.861,因此,认为甘蔗SCoT标记具有丰富的多态性。(2)成功实现了对107份甘蔗无性系的遗传多样性分析,得到供试甘蔗无性系之间的遗传相似系数值11,449个,其数值分布在0.375~0.881之间,实现了对所有供试甘蔗无性系的遗传相似性定量分析。(3)采用SCoT标记数据对107份供试无性系进行聚类分析和主成分分析。在遗传相似系数为0.674处,107份甘蔗无性系可划分6个类群:类群Ⅰ主要分布Q、闽糖和粤糖系列中的粤甘系列;类群Ⅱ主要分布FN系列;类群Ⅲ主要分布崖城和部分CP系列;类群Ⅳ主要分布ROC、部分CP和印度Co系列;类群Ⅴ仅有ROC1和Q162;类群Ⅵ为3个粤糖和其他系列无性系。主成分分析结果显示,107份供试无性系分为国内种质资源和国外引进种质资源两大类,两类种质资源间的遗传基础差异大,两类种质的杂交利用有望明显提高杂交后代的遗传多样性。(4)聚类结果显示,占我国甘蔗种植面积80%以上的栽培品种ROC22、ROC16和ROC10,分别分布于类群Ⅰ、类群Ⅱ和类群Ⅳ中,ROC16和ROC10的相似系数仅为0.449,ROC22和ROC10的相似系数也只有0.455,ROC22和ROC16的相似系数为0.722,因此,三个ROC系列主栽品种的遗传多样性比较丰富,这对甘蔗产业的安全来说是有益的。此外,进入国家区试的22个品种的平均相似度也只有0.593,说明我国自育品种的遗传多样性也相对较丰富。(5)按照选育单位不同,将107份甘蔗无性系划分为FN、ROC、桂糖、闽糖、崖城、粤糖、Q、CP、巴西、印度Co、云蔗11个主要系列和其他杂系列,对这12个系列内及系列间的遗传多样性评价,得出12个系列的遗传多样性指数h的变化区间为0.1635~0.3619,其他杂系列最高(0.3619),ROC(0.3496)和CP(0.3466)系列次之,云蔗系列(0.1635)最低,显示了不同系列遗传多样性差异较大。107份甘蔗无性系总体的遗传多样性指数Ht(0.3656)是系列间的遗传多样性指数h(0.3615)的1.01倍,是系列内遗传多样性指数Hs(0.2586)的1.41倍,因此,认为107份甘蔗无性系总体的遗传多样性主要分布于11个系列间。更多还原

【Abstract】 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: GroupⅠ, mainly the Q, Mintang,Yuegan series; GroupⅡ, mainly the FN series; GroupⅢ, mainly the Yacheng and part of the CP series; GroupⅣ, mainly the ROC, part of the CP and India Co series; GroupⅤ, including two clones, ROC1 and Q162; and GroupsⅥincluding 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 GroupⅠ, GroupⅡand GroupⅣ, 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.更多还原