甘蔗与斑茅杂交后代特殊染色体遗传机制研究

The type of chromosomal inheritance affects the process of nobilisation in sugarcane improvement, in-depth study will contribute to germplasm innovation and variety breeding. Our previous study indicated that the inheritance pattern was 2n + n or more than 2n + n transmission in the BC1 progeny between Saccharum spp. and Erianthus arundinaceus. Two hypotheses were proposed to explain the genetic phenomenon, but these hypotheses were ratiocinated between two successive generations from the GISH result of chromosomal composition. There is no evidence to determine when and how lead to the formation of the specific inheritance pattern. Therefore, it is important to determine the special mechanism of chromosomal inheritance in the BC1 progeny between Saccharum spp. and Erianthus arundinaceus for in-depth study. Using molecular markers, flow cytometry-genetics analysis and cytology technology, FISH chromosome karyotype and the system of flow sorting of individual Erianthus arundinaceus chromosome could be established, the chromosome type and chromosome transformation in the F1 female gamete at different stages of meiosis could be explored, as well as chromosomal composition and karyotype from the mitosis result of meristematic cells in root tip in F1 and BC1 could be determined. In addition, combined the performance results of yield, quality and resistance, the influence of different types of chromosomal inheritance on the yield, quality and resistance could be investigated. This study not only can analysis FISH chromosome karyotype and sort individual Erianthus arundinaceus chromosome, but also can determine this special mechanism of chromosomal inheritance. This study has important theoretical and practical significance for germplasm innovation and formulation of breeding strategies, selective breeding of breakthrough varieties.

染色体遗传类型影响甘蔗“高贵化”进程，深入研究利于种质创新和品种选育。本课题组前期研究发现甘蔗与斑茅BC1存在2n+n或超2n+n的遗传方式，提出两种假说解释该遗传现象，但假说是基于前后世代GISH的染色体组成推理而来，未能确定减数分裂何时、何种方式形成该遗传方式。本项目拟利用分子标记、流式细胞遗传学和细胞学技术相结合，研究斑茅FISH染色体核型，分选单条斑茅染色体，探索F1在减数分裂各阶段的雌配子染色体类型和染色体变化情况，结合F1和BC1的体细胞染色体组成和核型分析，对该特殊染色体遗传机制进行深入研究，并与抗性鉴定、产量和品质分析结果相联系，研究不同遗传类型对后代抗性、产量和品质的影响。本研究不仅可以获得斑茅染色体FISH核型并建立单条斑茅染色体分选技术体系，还可以探明甘蔗与斑茅的杂交后代的特殊染色体遗传机制，将对甘蔗种质创新和育种策略的制定，选育突破性品种具有重要的理论与实践意义。

染色体遗传类型影响甘蔗“高贵化”进程，深入研究利于种质创新和品种选育。本课题在前期研究发现甘蔗与斑茅BC1存在2n+n或超2n+n的遗传方式，并提出两种假说解释该遗传现象。课题利用分子标记、流式细胞术对该特殊染色体遗传机制进行深入研究，并与抗性鉴定、产量和品质分析结果相联系，获得以下主要结果：1、利用重复序列标记结合染色体长度，建立可以把一组染色体10条都分开的初步的FISH核型；利用玉米全染色体Oligo可快速识别斑茅染色体，完成斑茅1-10染色体Oligo-FISH核型。2、建立了适合甘蔗染色体分选的根尖细胞周期同步化技术体系，染色体悬浮液制备技术体系和染色体分选技术参数的模索，最终建立了稳定的GISHIS杂交后的斑茅染色体分选技术体系。3、研究了甘蔗与斑茅的F1的胚囊母细胞中染色体行为。4、创制含有1-2条斑茅染色体的材料66份，为染色体分选贮备了丰富材料。5、利用斑茅染色体FISH核型和对FI和BC1原位杂交结果，认为FDR + NSC遗传模式更符合BC1的染色体遗传机制。6、对BC1材料进行抗性鉴定，结果表明BC1抗黑穗病表现出性状分离，材料对花叶病、锈病具有普遍的抗性；甘蔗与斑茅杂交后代材料在产量上有明显优势，BC1的糖分总体较低，BC2、BC3的糖分回升，有的甚至优于对照种ROC22。.课题组与捷克和美国的染色体分选与Oligo研究先进单位建立的合作关系，与广西大学亚热带农业生物资源保护与利用国家重点实验室合作实现在国内的染色体分选。发表SCI论文6篇，核心期刊论文3篇，申请发明专利4件进入实审。创制的材料也是甘蔗育种重要中间材料，有可能从中选育出突破性品种。.项目成员2人晋升为副研究员；培养1位博士生毕业，8位硕士生毕业，2位硕士毕业后在本课题组攻读博士。