云南不同海拔八倍体割手密种质群体构建及其抗旱性遗传研究

Saccharum Spontaneum L. is one of the main stress resistance gene sources of sugarcane cultivars, with excellent rooting property, strong stress resistance and wide adaptation. Octaploid S.spontaneum of Yunnan has a significant meaning in population construction, good characteristics research based on cellular or molecular level and sugarcane breeding benefit from its small chromosome genome and stress resistance gene polymorphism. In view of this, two or three S.spontaneum from different altitudes will be used to create multi-type populations by crossing with original cultivars and other main parents. This could offer germplasms for good stress resistance characteristics analysis from the view of cytology and molecular genetics. In addition, analyze the phenotype and inheritance difference of main target traits. Finally, we will implement the drought resistance identification and genetic diversity evaluation of drought resistance functional markers from drought and high temperature resistance genes to reveal the correlation between drought resistance markers and stay-green traits. This study could resolve the difficulties of more evaluation but less utilization, and genetic population shortage in sugarcane breeding. Published 3 research papers.

割手密宿根性好、抗逆性强、适应性广等特性，是甘蔗品种抗逆基因的主要来源。云南八倍体割手密染色体数量少，抗逆基因多态性却更丰富，利用其构建遗传群体对研究其优良特性的细胞、分子遗传，以及育种利用均具重要意义。本项目拟选用原生地不同海拔的云南八倍体割手密2-3个与栽培原种、常用亲本正反交、测交、回交，创制多类型遗传群体，（1）为割手密优良抗逆特性的细胞、分子遗传研究奠定种质基础；(2)研究不同海拔云南八倍体割手密主要性状表现型差异及其遗传；（3）对不同世代群体材料进行抗旱性鉴定，选用根据植物抗旱和耐高温相关基因设计引物组成的功能标记对持绿性极端材料进行抗旱功能标记的遗传多样性评价，研究云南八倍体割手密抗旱相关基因功能标记多态性与持绿性的相关性，初步解析云南八倍体割手密抗旱性遗传及其育种潜力。解决甘蔗野生种评价多，杂交利用少，优良性状遗传研究群体困乏等问题。发表研究论文3篇。

项目针对甘蔗遗传背景复杂、遗传群体构建困难的问题，选用染色体较少的八倍体云南割手密与栽培原种，构建多亲群体，并开展割手密育种潜力及抗旱性遗传研究，旨在解决甘蔗野生种质评价多，杂交利用少等问题。获得以下结果：（1）利用三种生态型四个海拔区域的八倍体云南割手密构建群体50个，群体构建兼顾了割手密细胞质、核遗传，起始亲本本土化特征突出，构建方式保证了染色体充分重组，后代PCR扩增多态性丰富。（2）育种潜力评价结果表明云南八倍体割手密杂交F1、F2代性状变异丰富，对培育多茎、强宿根、高糖种质更具潜力；筛选出优异杂交组合6个，高产高糖育种亲本15份。（3）通过人工水分胁迫鉴定出高度抗旱性种质18份，群体材料抗旱功能标记多态性分析结果表明群体的血缘基础越丰富，其多态性就越高； 利用MLM模型共检测到与抗旱性状关联的SSR标记14个，对表型变异的解释率范围为11.06% ~ 36.32%。研究结果一是可为甘蔗基因定位及遗传研究提供必备的杂交群体，为甘蔗高产高糖和抗逆育种提供优良组合和优异亲本，二是为利用SSR标记开展甘蔗分子辅助育种奠定了基础。项目实施发表核心期刊论文3篇。