白菜型油菜抗寒性评价指标体系及数学模型构建

Identification of cold resistance is an important technical foundation for the breeding for cold resistance as well as genetic mapping and analysis of relevant genes. In this study, 22 cultivars (lines) of rapeseed (Brassica rapa L.) are selected and planted at six pilot sites under different eco-conditions by sowing in autumn. Intra-cultivar changes and inter-cultivar variations in seedling morphology, leaf tissue anatomy and stomatal morphology are examined and plant physio-biochemical parameters and accumulation and distribution of photosynthetic products are determined in rapeseed before (early October) and after evident cooling (mid-November) in the pre-winter growth stage, in order to examine the correlation between plant indicators and cold resistance (winter rate). Dimensional gel electrophoresis is employed to detect differential protein expression in pre-winter leaves and wintering roots among cultivars. Public resource search engine platform or cold-resistance gene sequences are used to develop molecular markers, and hybridization and backcross populations are used to screen out polymorphic markers, in order to establish a molecular marker technique for identification of rapeseed. Additionally, selected cultivars are planted at the pilot site under specific eco-conditions (Qinchuan). The correlation between vernalizing parameters and cold resistance is analyzed to identify relevant indicators significantly related to cold resistance in the rapeseed cultivars. Finally, an integrated index system and a mathematical model are established for identification and evaluation of cold resistance in rapeseed. This work will lay a foundation for breeding for cold resistance and genetic analysis in rapeseed.

抗寒鉴定是白菜型冬油菜抗寒育种、抗寒相关基因定位和遗传分析等的重要技术基础。本项目拟在6个不同生态条件试点，选择22个白菜型油菜品种（系）秋播种植，冬前苗期分别于明显降温前（10月上旬）后（11月上中旬），观测植株形态、叶片组织解剖结构和气孔形态特征、测定生理生化、光合和产物积累分配参数等的变化和品种间差异，分析上述各指标与抗寒性（越冬率）间的相关性；双向电泳分析冬前叶片和越冬期根部品种间差异表达蛋白；在公共资源平台检索或依据抗寒基因序列研发分子标记，利用杂交及回交群体，筛选多态性标记，建立白菜型油菜分子标记鉴定技术；在特定生态条件试点（秦川）春播种植，通过分析春化特征参数与抗寒性间的相关关系，筛选与品种抗寒性显著相关指标，建立白菜型油菜抗寒性鉴定与评价的综合指标体系及其数学模型，为白菜型冬油菜抗寒育种及遗传分析等研究奠定基础。

抗寒性鉴定是白菜型冬油菜抗寒育种、抗寒相关基因鉴定及遗传分析的重要基础。本研究在4个不同的生态条件试点，选择8个抗寒性不同的白菜型冬油菜品种为实验材料，根据相关的形态及生理指标建立抗寒性建立与评价的综合指标和数学模型。结果表明：.1、白菜型冬油菜北移过程中，侧裂叶对数总体呈增加趋势，苗期从半直立向匍匐方向变化。.2、冷胁迫下抗寒性强的品种抗氧化能力较高，叶片中含有较高的可溶性蛋白。.3、低温胁迫下，气孔张开比和张开度与品种抗寒性呈正相关，抗寒性强的品种处于开放状态的气孔占很大的比例。.4、叶绿体超微结构分析显示超强抗寒品种多数基粒保持完整垛叠结构，部分基质片层出现断裂，有一定数量的叶绿体淀粉粒积累。.5、外源ABA喷施可增加白菜型冬油菜抗寒性。.6、蛋白组学研究发现白菜型冬油菜低温胁迫后叶片显著富集通路为代谢途径与次级代谢合成途径，而根部除代谢、次级代谢物合成通路外，淀粉和蔗糖代谢通路也显著富集，对白菜型冬油菜抗寒性具有重要作用。