小麦面包、面条优质兼用的淀粉理化特性及其合成机理研究

Bread quality has been considering the major objective of quality genetic improvement for short of elite cultivars, while noodle is the most popular food nationally and widely consumed. Therefore, wheat cultivar with both good bread and noodle quality would be more suitable for our production conditions and traditional consumption custom. It is deduced from previous research that starch physicochemical properties maybe play a vital role in the breeding programmes. Six types of wheat cultivars, including cultivars with good or bad bread quality, noodle quality or both of them, will be screened from collected germplasm worldwidely. Then their protein and starch physicochemical properties, together with bread and noodle making quality, were compared to find the relationships between starch properties and protein characteristics, bread and noodle quality. The key parameters affecting bread and noodle quality greatly will be selected to improve wheat quality in breeding programmes. Starch (granules) will be extracted from 6 types of wheat cultivars and blended with other flours proportionally. Then the blended flours were also compared with each other in the bread and noodle processing quality in order to confirm the function of starch physicochemical properties to end use, as well as the key parameters. The influences of genotype, environment and their interactions on starch physicochemical properties, bread and noodle quality will be invested through trials at three locations during three crop seasons. The dynamic changes of gene expressions and activities of 4 key starch biosynthetic enzymes in developing endosperm during grain filling will be detected for further understanding of the biosynthesis mechanism of starch physicochemical properties. All the results are essential for current wheat genetic improvement and cultivation.

面包品质是我国小麦改良的重点，面条是我国的传统主食和消费主体，面包、面条优质兼用型品种更符合我国国情。分析表明淀粉理化特性改良可能是选育兼用型优质小麦的关键。 筛选面包优质和劣质、面条优质和劣质、二者兼优和均劣6类面包和面条品质差异显著的典型品种，对比其蛋白和淀粉理化特性，进行面包和面条评价，明确淀粉理化特性与蛋白特性的关系及其对面包和面条品质的影响，筛选影响面包和面条品质的关键淀粉指标。 提取6类品种的淀粉（粒），分别添加到其他类型品种面粉中，比较其淀粉理化特性和面包、面条品质的变化，进一步明确淀粉特性对面包和面条品质的影响及其作用机理，验证关键淀粉指标的作用，指导育种实践。 将6类材料3年3点试验，明确基因型和环境对淀粉理化特性和面包、面条品质的影响；检测籽粒灌浆期4种淀粉合成关键酶基因表达和酶活性的动态变化，明确淀粉理化特性形成的酶学机理和调控机制，指导小麦遗传改良和栽培生产。

淀粉理化特性对小麦品质至关重要。筛选出6类12个面包、面条品质不同的小麦品种，其淀粉理化特性存在显著差异，包括淀粉组分、支链淀粉链长分布、颗粒大小和分布、糊化、膨胀和胶凝特性。研究的大多数参数与面包和面条品质显著相关，说明淀粉特性对小麦品质有重要影响。支/直链淀粉含量比例、支链淀粉短链（2≤DP≤10）比例、C-型淀粉粒比例、糊化峰值粘度和DSC胶凝终止温度可作为改善小麦加工品质的有效指标，5项指标变化范围分别在2.1－2.6、47.8－51.0%、36.2－46.7%、2890－3450 cP、68.5－69.6℃时面包和/或条品质较好。.环境对小麦品质有重要影响，通过2年3点试验结果表明品种和环境对12个品种面包、面条总分均存在极显著影响，面包、面条评分各项指标主要受品种的极显著影响。配粉能够显著改善劣质面粉面包、面条品质，添加30%的优质面粉就可以明显改善面粉品质，当添加到50%优质面粉时，面条评分达到85分，面包评分也接近85分。.普通小麦淀粉合成调控的研究相对较少，鉴定出57个淀粉合成基因，系统进化分析表明与短柄草遗传距离较近，与水稻和高粱相距稍远。表达谱分析表明绝大部分淀粉合成基因在生殖器官中高效表达，说明其重要功能；12个基因在干旱胁迫6 h后上调，6个基因在热胁迫6 h后上调，说明淀粉合成对抗逆也有一定的作用。.14-3-3基因家族成员参与许多生物过程中的调节，从济麦22中克隆了14-3-3基因，亲和层析表明其与5个淀粉合成关键酶存在互作，说明参与了淀粉合成的调控。基因表达分析表明16个TaGF14基因是组成型表达，花后20 d籽粒中表达量最高，另外部分TaGF14还参与抗旱调节和耐热反应。.检测比较了12个品种籽粒灌浆过程中11种淀粉合成关键酶编码基因的动态表达情况，发现品种间存在明显差异。.引进博士1名，培养博士后1人、毕业研究生3人，新招收博士后1人；取得知识产权18项，其中育成优质小麦新品种2个，转让收益1580万元。