Liu Jian-Jun

Molecular mapping of powdery mildew resistance gene in wheat cultivar Jimai 22

Wheat powdery mildew,caused by Blumeria graminis f.sp.tritici,is one of the most important diseases of wheat (Triticum aestivum L.)worldwide.Breeding resistant wheat cultivars is the most economical and effective approach to control the disease.Jimai 22,a newly released wheat cultivar with high yield,broad adaptability,and good quality,is related to broad-sprectrum resistance to the isolates of B.graminis f.sp.tritici at both seedling and adult plant stages.To map the resistance gene of Jimai 22 on wheat chromosome,we used a highly virulent isolate E20 to screen the F2 plants and F2:3 lines derived from the cross of Jimai 22/Chinese Spring.Genetic analysis indicated that Jimai 22 carried a single dominant gene for resistance to powdery mildew,designated PmJM22 tentatively.Using bulked segregant analysis(BSA)with SSR and STS markers,PmJM22 was located to chromosome 2BL.Linkage analysis indicated that the resistance gene was linked to four SSR and five EST markers,with genetic distances from 7.7(Xwmc149)to 31.3 cM(Xbarc101).Based on the origins,chromosome locations,and reaction patterns,PmJM22 is different from all the known powdery mildew resistance genes Pm6,Pm26,Pm33,and Mlzec1 on chromosome 2BL.

Identification of 1BL/1RS translocation based on mixograph parameters in common wheat

1BL/1RS translocation has been widely used for improving agronomic performance and disease resistance in wheat(Triticum aestivum L.),however,it has strong negative effect on processing quality.To develop a method for 1BL/1RS transloca-tion identification with mixograph parameters,404 advanced lines from 146 crosses in 2005–2006(experiment I) and 175 ad-vanced lines and main cultivars of Shandong province(experiment II) in 2005–2006 and 2006–2007 cropping seasons were used in this study.All materials were sown under irrigation condition in a randomized complete design with 1 replication in Jinan.The genetic effect of 1BL/1RS translocation on mixograph parameters was investigated.The variations of mixograph parameters under different combinations of the high molecular weight glutenin subunits(HMW-GS) and low molecular weight glutenin subunits(LMW-GS) were also analyzed.1BL/1RS translocation lines showed significantly shorter mixing time,less bandwidth of peak and bandwidth after 1 min peak,and higher angle of descent and the bandwidth ratio(the ratio of bandwidth of peak/bandwidth after 1 min peak) in comparison with non-1BL/1RS translocation lines.It indicated that the 1BL/1RS translocation has deleterious effects on mixograph parameters.Mixograph of the 1BL/1RS translocation was characterized with the bandwidth sharply declin-ing and narrowing after 1 min peak,and increasing the bandwidth ratio,whereas the bandwidth of non-1BL/1RS translocations declined gently after 1 min peak or had a longer mixing tolerance,and had a little variation about the bandwidth ratio.Further-more,85.2%(experiment I) and 96.8%(experiment II) accuracies were achieved in grouping the 1BL/1RS translocation and non-1BL/1RS translocation on the basis of the band width ratio,i.e.,1BL/1RS translocation line had a value more than or equal to 1.6,and non-1BL/1RS translocation line had a value smaller than 1.6.Although the Glu-B3 alleles showed better quality parame-ters when HMW-GS 5+10 was presented,it was still the most unfavorable allele on mixograph parameters among all Glu-B3 al-leles.Therefore,mixograph parameters could be used to determine the rheological properties and the presence of 1BL/1RS translocation.

Effect of allelic variation at the Glu-1 Loci and 1B/1R translocation on the quantity of gluten protein fractions and pan bread making quality in common wheat

选用北方冬麦区近年来育成的优质强筋品种及山东省主栽品种共42份,采用反相高效液相色谱法（RP-HPLC）和凝胶色谱法（SE-HPLC）对小麦贮藏蛋白组分进行量化,分析了不同高分子量谷蛋白亚基（HMW-GS）组成对其表达量、面团流变学特性和面包加工品质的影响。结果表明,Glu-D1位点对谷蛋白亚基含量和加工品质的加性效应最大,达5%显著水平,贡献率为28.5%～71.3%。在Glu-A1和Glu-D1位点,单个亚基对谷蛋白亚基含量和加工品质的贡献分别为1〉2^＊〉N和5＋10〉2＋12〉4＋12,而在Glu-B1位点,则表现为差异不显著。不同亚基组合的HMW–GS表达量差异达5%显著水平,相同亚基组合的品种间贮藏蛋白组分表达量的变异较大,亚基表达量的差异可能是导致品种间品质差异的重要原因。1B/1R易位显著降低LMW-GS、谷蛋白总量和%UPP,导致加工品质变劣。选择具有优质亚基组合,且谷蛋白亚基表达量高的类型,是有效改良面筋强度,进一步提高优质新品种选育的有效途径。