黑龙江省超强面筋小麦的育种策略和方法

根据黑龙江省的生态条件和我国强筋小麦的主要用途,提出了在黑龙江省培育和种植超强筋小麦及利用生化标记辅助选择等技术进行连续选择性回交等选育超强筋小麦的方法,分析了超强筋小麦的HMW-GS组成。     

小麦胚乳蛋白遗传变异及基因多态性研究进展

小麦的品质可分为营养品质和加工品质,其中加工品质主要由小麦胚乳贮藏蛋白决定,小麦胚乳贮藏蛋白主要由麦谷蛋白和麦醇溶蛋白构成。不同小麦品种的蛋白组成、数目都存在较大的差异,小麦基因具有多态性。介绍了小麦胚乳蛋白基因多态性研究进展。这对改良我国小麦品种、提高小麦品质具有积极的指导作用,对物种基因资源的发掘与保护也具有非常重要的意义。     

104份甘肃小麦品种主要品质基因的分子标记检测

高分子量麦谷蛋白亚基、黄色素质量分数和1B/1R易位系均影响小麦的加工品质。为明确相关品质性状基因在104份甘肃育成小麦品种中的分布,并为小麦品质育种提供亲本材料,利用高分子质量谷蛋白亚基Dx5、Bx7、By8、By9和黄色素质量分数基因及1B/1R易位系的特异性标记对104份小麦品种进行检测。结果表明,含基因Dx5、Bx7、By8、By9和1B/1R易位系的品种分别占总品种数的63.46%、76.92%、52.88%、45.19%和45.19%。含有等位基因Psy-A1a和Psy-A1b品种分别占总品种数的60.58%和21.15%,其黄色素质量分数均值差异达到显著水平(P0.05)。总体来看,甘肃育成小麦品种中含适合加工馒头和面粉等传统食品的单个品质优质基因频率较高,而优质基因组合的比例较低,具有黄色素质量分数较高的品种比例高。     

Glu-B1位点亚基色谱鉴定及7OE对面团强度的影响

准确鉴定高分子量谷蛋白亚基(HMW-GS)及探讨其对面团特性的影响是小麦品质研究的重要内容。用聚丙烯酰胺凝胶电泳(SDS-PAGE)和反相高效液相色谱(RP-HPLC)对62份品种(系)的HMW-GS组成进行鉴定。结果表明,结合SDS-PAGE和RP-HPLC两种方法可以对Glu-B1位点,尤其是Glu-B1(7 8)进行有效鉴定。选用13份姊妹系为材料,使用RP-HPLC和凝胶色谱(SE-HPLC)方法,研究了Glu-B1al(7OE 8*)以及贮藏蛋白组分含量对面团强度的影响。结果表明,Glu-B1al(7OE 8*)可显著提高HWM-GS总量和面团强度,7OE可作为优质亚基用于强筋小麦育种。相关性分析表明,谷蛋白总量、HWM-GS、LMW-GS以及x-HMW含量与最大抗阻力呈1%显著正相关,相关系数分别为0.76、0.76、0.77和0.72。SDS-不溶性谷蛋白大聚体(UPP)占谷蛋白聚合体总量的百分比与揉面仪峰值时间、粉质仪形成时间和稳定时间以及最大抗阻呈1%或0.1%显著正相关,相关系数分别为0.77、0.90、0.89和0.87。醇溶蛋白与谷蛋白含量的比值与揉面仪峰值时间呈1%显著负相关,相关系数为-0.69;与粉质仪稳定时间和最大抗阻呈5%显著负相关,相关系数分别为-0.58和-0.64。HPLC可有效分离和量化HWM-GS,并作为小麦品质育种有效的辅助手段。     

Breeding for end-use quality: Reflections on the Nebraska experience

Every cultivar released in Nebraska must have four characteristics:improved agronomic performance relative to existing cultivars, exceptionalwinterhardiness, resistance to Puccinia graminis (the causal agent ofstem rust), and acceptable end-use quality. This paper will discuss ourstrategy for breeding cultivars with acceptable end-use quality. Allexperimental lines are derived from crosses with at least one or moreparents with acceptable end-use quality. As soon as individual lines areidentified (F₅) generation, microquality analyses are conducted andapproximately 10% are discarded on the basis of poor end-use quality. Inthe F₆ and later generations, samples are composited from three ormore locations/year, milled on a Buhler Mill, and baked using 100 g offlour per loaf. Though genotype-by-environmental interactions are large forend-use quality traits, composite samples are satisfactory for determiningthe end-use quality when repeated over time. By using phenotypicselection, the program has released cultivars with acceptable qualityinvolving known `poor' quality genes and chromosomes, such ashigh-molecular weight (HMW) glutenin subunits 2+12 (Scout 66 andLancota), 1BL.1RS (heterogeneous in Rawhide and homogeneous inCougar), and 1AL.1RS (heterogeneous in Nekota and Niobrara).Phenotypic selection is preferred to genotypic selection.     

Changes in expression of HMW glutenins of wheat (Triticum aestivum L.) induced by nitrosoethylurea

The application of a chemical mutagen, N-nitroso-N-ethylurea, to the grains of wheat (Triticum aestivum L.) cv. ‘Viginta’, provided a mutant line,‘NT-10′, with an altered composition of high molecular weight (HMW) glutenin subunits. The qualitative mutation was detected in the Glu-B1 locus by electrophoretic analyses of glutenins. Instead of the HMW glutenin subunits 7 + 9 present in the original genotype, a separate HMW subunit 6 was expressed in the mutant line. The other glutenin and gliadin proteins of the mutant line remained unchanged. The mutant line is also characterized by several changes in morphological and physiological characters—stronger stem, wider leaf, bigger spike and higher grain hardness. This is the first communication of the possibility of changing the composition of high molecular weight subunits of wheat glutenin by means of mutagenesis.     

High molecular weight glutenin subunits of current bread wheats grown in Iran

Variation of high molecular weight gluteninsubunits (HMW-GS) at the Glu-1 lociwas studied using SDS-PAGE method in 43advanced lines or cultivars commonly grownin Iran. Fourteen alleles and 21 alleliccompositions were detected. Among the 43bread wheats analysed only five showed aunique HMW-GS composition. The mostfrequent HMW-GS patterns were 2^*, 7+8,2+12 and 2^*, 17+18, 2+12 which wereobserved in 13 and six cultivars,respectively. In the remainings, each twoto three lines or cultivars showed a commonHMW-GS pattern. Therefore, allelicvariation at Glu-1 loci is of limitedvalue for cultivar identification comparedwith loci controlling gliadins. Sevencultivars were observed to consist of twoto three biotypes with different alleles.In cultivar Mahdavi a biotype showedinactivity at the Glu-B1 locus. Analready reported rare subunit pair'2^***+12' at Glu-D1locus was found in cultivar Kavir. Theresults of scoring cultivars for theirquality based on the HMW-GS compositionswith an average score of eight, wasgenerally good. Cultivars Inia, Tajan, andadvanced lines N-75-11 and N-75-15 showedquality score equal to 10, whereas Alamootand C-75-5 showed quality scores equal tofive. The quality of former and latterlines and cultivars were considered highestand lowest, respectively. The resultsobtained in this study are useful inbreeding programs to improve bread makingquality, developing uniformity andimproving heterogeneous cultivars by meansof selection of the best genotypes.