Breeding a hard, winter type durum wheat by the gene shuttling method

普通小麦(基因组，AABBDD)携带重要的农艺性状基因，如与烘烤品质有关的Glu-D1d基因(位于1D染色体上)、控制半矮秆小麦生长的RHT2基因(位于4D染色体上)、与强冬生长习性有关的vrn3基因(位于5d染色体上)等，这些都是硬粒小麦(AABB)所没有的。本研究旨在利用硬粒小麦的D-基因组染色体置换系将这些基因导入硬粒小麦。(1)Glu-D1d基因的转移：用兰登的1D(1A)和1D(1B)代换系与两个面包小麦品种Max和Stoa杂交，这两个品种携带Glu-D1d等位基因，以获得最好的麦谷蛋白组分。在纯合子条件下，成功地选择了几个具有2n=28和Glu-D1d等位基因的F2植株。对自花授粉结实的籽粒进行收获，并测定面粉品质。与朗顿面粉相比，两种剂量的Glu-D1d等位基因没有改变面粉的蛋白质含量，但其混合耐受性明显提高，面包体积和质构得到改善。(2)Transf…较多的Rht基因：将携带Rht1和Rht2两个半矮秆基因的日本品种Norin 10与兰登杂交，在F_2代对染色体数和株高进行选择。获得了一株Rht1和vrn1基因均为纯合子的F3株系。用Norin 10与兰登的4D(4A)和4D(4B)代换系杂交，对F_2代进行染色体数目和株高选择。(3)vrn基因的转移：将兰登5D(5B)代换系与两个日本冬小麦品种杂交，对F_2代的染色体数目和F_3代的生长习性进行选择。获得了几个具有较强越冬生长习性的F3植株，染色体数目接近2n=28，推测为这两个VRN基因的纯合子。较少

Common wheat (genome, AABBDD) carries agronomically important genes, such as Glu-D1d gene (on chromosome 1D) for high baking quality, Rht2 gene (on 4D) for semidwarfism, and vrn3 (on 5D) for strong winter growth habit, which are not found in durum wheat (AABB). The present investigation aimed to transfer those genes to durum wheat using the D-genome chromosome substitution lines of a durum wheat.(1) Transfer of the Glu-D1d gene : Langdon's 1D (1A) and 1D (1B) substitution lines were crossed to two bread wheat cultivars, Max and Stoa, which carry a Glu-D1d allele for the best glutenin fractions. Several F_2 plants having 2n=28 and Glu-D1d allele in the homozygous condition were successfully selected. Grains set by self-pollination were harvested and flour characteristics were tested. Two doses of the Glu-D1d allele did not change protein content of flour but its mixing tolerance clearly was increased, and loaf volume and texture were improved, comparing to the Langdon's flour.(2) Transf … More er of the Rht genes : Japanese cultivar, Norin 10, that carries two semidwarf genes, Rht1 and Rht2, was crossed to Langdon and in the F_2 generation selection was made on chromosome number and plant height. An F_3 line was obtained that carries the Rht1 and vrn1 genes both in homozygous condition. In another experiment, crosses were made between Norin 10 and Langdon's 4D (4A) and 4D (4B) substitution lines and in the F_2 generation selection was made on chromosome number and plant height. Several short culm plants having nearly 2n=28 were obtained, which are assumed to be the Rht2 homozygote in the durum background.(3) Transfer of the vrn genes : To produce a durum line having both the vrn1 and vrn3 genes, Langdon's 5D (5B) substitution line was crossed to two Japanese winter cultivars of common wheat, and selection was made on chromosome number in the F_2 generation, and on growth habit in the F_3 generation. Several F_3 plants having strong winter growth habit and nearly 2n=28 chromosomes were obtained, which are assumed to be the homozygote of both vrn genes. Less