【作者】 李桂萍；

【导师】 陈佩度；

【作者基本信息】 南京农业大学 ， 作物遗传育种， 2007， 博士

【摘要】 小麦白粉病是由白粉菌（Erysiphe graminis Dc．f．sp tritic Marchal）引起的世界性真菌病害，培育抗性品种是控制白粉病的有效途径。南京农业大学细胞遗传所选育的小麦-簇毛麦6VS/6AL易位系带有目前对小麦白粉病抗性最强，抗谱最广的基因Pm21，已作为抗源选育出一批高抗白粉病的新品种和新品系。可以预见6VS/6AL及其衍生系将在我国小麦抗病育种和生产中发挥重要作用。系统深入研究小麦背景中6VS/6AL易位染色体的检测、鉴定方法以及6VS/6A易位染色体在不同小麦背景中的遗传传递及其对普通小麦农艺性状和品质性状的遗传效应，对于充分利用外源染色体携带的有用基因具有十分重要的意义。外源基因的有效转移与利用，在很大程度上依赖于对导入小麦背景中的外源染色体或染色体片段的准确鉴定。本研究利用白粉病抗性鉴定、染色体C-分带、荧光原位杂交（FISH）和STS-PCR分子标记等方法，对征集的22份国内育种单位及本课题组用6VS/6AL易位系做亲本育成的高代品系和新品种进行了6VS/6AL易位染色体的鉴定并对几种鉴定方法进行了比较。结果表明，在这22份材料中共有18份材料含有纯合6VS/6AL易位染色体，可以用来研究外源染色体对小麦农艺性状和品质性状的影响。对多数育种者来说，在鉴定6VS/6AL易位染色体的方法中，以PCR为基础的STS-PCR分子标记是一种快速有效的检测方法，最易于在小麦育种中进行标记辅助选择．本研究选用6组21份含有纯合6VS/6AL易位染色体的高代品系和新品种及其轮回（杂交）亲本，以及3份含有杂合6VS/6AL的高代品系和5个用6VS/6AL易位系作亲本组配的杂交F₂群体为试验材料，研究了6VS/6AL易位染色体在不同小麦遗传背景中对小麦农艺性状和品质性状的影响。结果表明，在农艺性状方面，利用6VS/6AL易位系做抗源亲本选育高代品系时，6VS/6AL易位染色体对后代品系的农艺性状诸如产量性状、小穗数、穗粒数和穗粒重等没有表现出明显的影响，对旗叶面积和千粒重表现出了一定的正向效应。多数6VS/6AL后代品系的株高与亲本相比有所增加，但在同一组合的不同品系之间表现出了一定的差异，说明在育种过程中对株高的选择具有重要的作用。在品质性状方面，6VS/6AL易位染色体对籽粒容重和出粉率有一定的负向效应，在用6VS/6AL易位系进行抗病育种过程中应该注重对这几个性状的选择。6VS/6AL对沉降值和面团强度有一定的正向效应，含有6VS/6AL的后代品系与其亲本相比拉伸面积和最大抗拉伸阻力明显提高。6VS/6AL易位对籽粒硬度、籽粒蛋白质含量、和面特性以及粉质参数不会产生明显的影响。含6VS/6AL的高代品系与其亲本相比大多数品系在淀粉糊化特性的各项指标有所下降，但淀粉糊化特性在不同遗传背景与环境之间有一定的变异，通过合适的选择可以避免淀粉糊化特性的下降．6VS/6AL易位系对白粉病免疫，并且遗传稳定，对小麦的加工品质没有明显的影响，对小麦的抗病育种将是很好的抗源亲本．利用高抗白粉病的普通小麦-簇毛麦6VS/6AL易位系92R137与不抗白粉病的栽培品种百农64、百农9310、邯5310、小偃54、淮麦20、徐麦856进行杂交，并用这些品种分别与杂种F₁进行正反回交．对杂种F₁的花粉母细胞减数分裂中期Ⅰ的细胞学行为进行观察，结果表明：在减数分裂中期Ⅰ易位染色体6VS/6AL通常以6AL与6A染色体配对形成棒状二价体．各杂种F₁高抗白粉病，在F₂中有69.0％-74.0％植株抗白粉病，表明位于6VS上的抗白粉病基因Pm21在不同小麦背景中呈显性单基因遗传．由于6VS与6AS在通常情况下不发生配对交换，因此可通过白粉病抗性鉴定并结合利用6VS上的分子标记来跟踪6VS/6AL易位染色体的传递．测交结果表明，在不同小麦背景中6VS/6AL易位染色体能够正常传递．6VS/6AL易位染色体通过雌配子的传递率为49.2％（45.8％-54.9％），通过雄配子的传递率为44.7％（43.1％-46.8％），均接近50％的理论值．但在各组合中，6VS/6AL易位染色体通过雄配子的传递率均低于雌配子的传递率．更多还原

【Abstract】 Powdery mildew, caused by Erysiphe graminis Dc. f.sp.tritici Marchal, is one of the major diseases of common wheat worldwide. Development and utilization of wheat cultivars with resistance gene is an efficient, economic and environmentally safe strategy to control powdery mildew. T. aestivum-H. villosa 6VS/6AL translocation lines were highly resistant to powdery mildew with resistance gene Pm21 located on chromosome 6VS. The 6VS.6AL translocation lines have been extensively used as resistant parents in crossing programs and several cultivars, such as Shimai 14, Xingmai 2, Neimai 9 and Nannong 9918, with resistance to powdery mildew were released in Hebei, Sichuan and Jiangsu. When alien chromosomes or chromosome fragments carrying target genes are transferred to wheat, undesirable traits can be introduced simultaneously. In order to make full use of 6VS/6AL translocation line in breeding program, research work on translocation chromosome identifying in wheat background, effects of the 6VS/6AL translocation on agronomic traits and quality characters in different genetic background and translocation chromosome transmission has been done as follows:Powdery midew resistance tests, chromosome C-banding, fluorescence in situ hybridization（FISH） and a co-dominant PCR marker(NAU/Xibao15₉₀₂ for 6VS, NAU/Xibao15₉₈₄ for 6AS) were used to assay for 6VS/6AL translocation chromosomes in different genetic background in order to confirm the tested materials from different ecological zones. The resistance tests, C-banding, GISH and PCR results confirmed that two 6VS/6AL translocation chromosomes were present in 18 derivatives aomong 22 tested materials. STS-PCR marker made it possible to screen a large number of genotypes reliably and rapidly in practical breeding programs for the presence/absence detection of 6VS/6AL. Thus, it is highly reproducible and reliable, and can be used in breeding program.Twenty-one common wheat cultivars and advanced lines carrying a 6VS/6AL translocation and five parents, three pairs of advanced lines with and without the 6VS/6AL translocation chromosomes and five crosses F₂ were selected and analysed for agronomic traits and quality characters including grain protein and dough properties of wheat to understand the effects of the 6VS/6AL translocation on agronomic characters and quality characters in different genetic background. In general, there were no significant differences between 6VS/6AL lines and their recurrent parents in agronomic, including grain yield, grains/spike and grain weight/spike. 6VS/6AL lines showed slightly but significantly higher thousand-kernel weight, flag leaf area and plant height. However, significant variation occurred for all traits among sister lines from the same cross and among different crosses, indicating that additional selection and parent selection could lead to further improvements. In quality traits, no significant difference was observed between 6VS/6AL derivatives and their recurrent parent in grain protein, mixograph dough properties and farinograpg. Maybe 6VS/6AL translocation has some positive effect on Zeleny sedimentation and extensograph. Starch pasting characteristics measured by Rapid Viscosity Analyzer varied with genetic background and growing locations, better starch pasting characteristics would be obtained by selecting suitable parent and locations. However, 6VS/6AL derivatives show slight, but significant negative effect on test weight and flour yield. Thus, selection for these traits should be taken into account in breeding when using 6VS/6AL translocation line as parent. It is concluded that 6VS/6AL translocation can be used in wheat breeding programs as valuable donor for resistance to powdery mildew with no obvious undersirable effect on agronomic traits and bread making quality traits.The 6VS/6AL translocation line 92R137（highly resistant to powdery mildew） were respectively crossed to common wheat varieties Bainong 64, Bainong 9310, Han 5310, Xiaoyan 54, Huaimai 20 and Xumai 856 introduced from different areas of China and hybrids F₁ were backcrossed with respective varieties as male and female. Fluorescence in situ hybridization（FISH） on hybrid F₁ PMC at MI was used to study the pairing of 6VS/6AL translocation chromosome of hybrid F₁ in different wheat background. The rod bivalent formed by 6AL of translocation chromosome and chromosome 6A was observed in（translocation line×different variety） F₁ plants. All the F₁ plants expressed high resistance to powdery mildew. It indicated that Pm21 gene on 6VS inherited dominantly and expressed well when transferred to different wheat genotype. In hybrid F₂, there were 69.0%—74.0% plants highly resistant to powdery mildew, close to the transmission of one dominant gene expected value of 75%. In general situation, 6VS can not pair and crossover with 6AS, so powdery mildew resistance and molecular marker on 6VS can be together used to trace the transmission of 6VS/6AL translocation through gametes. The result of testcrosses showed that translocation chromosome 6VS/6AL can transmit to offsprings stably, and the transmission frequency of 6VS/6AL was higher through female gametes（49.2%） than through male gametes（44.7%）, but all of them had not significant difference with expected value of 50%.更多还原