Chromosome substitutions of Triticum timopheevii in common wheat and some observations on the evolution of polyploid wheat species
Chromosome substitutions of Triticum timopheevii in common wheat and some observations on the evolution of polyploid wheat species
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DOI：
10.1007/bf00223462
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发表时间：
1996-12-01
影响因子：
5.4
通讯作者：
Cox, TS
中科院分区：
文献类型：
--
作者：
BrownGuedira, GL;Badaeva, ED;Cox, TS
是否这两个四倍体小麦种，众所周知的Triticum turgidum L. （macaroni wheat， AABB基因组）和鲜为人知的T. timopheevvii Zhuk。(A(t)A(t)GG)，来自同一或不同的二倍体物种的单系或双系起源提出了一个有趣的进化问题。此外，timopheevi及其野生型T. araratium是通心粉和面包小麦改良的重要遗传资源。为了研究这些目的，分析了T. timopheevi染色体对T. aestivum 'Chinese Spring' （AABBDD）缺失染色体的替代和遗传补偿能力。将“中国春”非整倍体（零体-四体组）与一株提莫费耶夫和一株陶氏Aegilops tauschii两倍体杂交，分离出单体条件下的提莫费耶夫染色体。将F-1杂种与中国春非整倍体回交1 ~ 4次，不选择感兴趣的T. timopheevi染色体。虽然发现了涉及所有A(t)-和g基因组染色体的自发替换，但目标t . timopheevi染色体并不总是恢复。选择自发替换的系进行回交。共分离到6个t . timopheevi染色体替换：6A(t) （6A）、2G （2B）、3G （3B）、4G （4B）、5G （5B）和6G （6B）。替代系形态和育性正常。timopheevi的6A(t)与1G染色体发生易位，导致group-1麦胶蛋白位点转移到6A(t)上。染色体2G取代2B的频率高于预期，并且可能携带一些外来物种2组染色体上存在的配子体杀子基因的同等位基因。我们的数据表明四倍体小麦物种有一个共同的起源，但由于存在不同的基因组间易位谱，因此来自不同的杂交事件。
Whether the two tetraploid wheat species, the well known Triticum turgidum L. (macaroni wheat, AABB genomes) and the obscure T. timopheevii Zhuk. (A(t)A(t)GG), have monophyletic or diphyletic origin from the same or different diploid species presents an interesting evolutionary problem. Moreover, T. timopheevii and its wild form T. araraticum are an important genetic resource for macaroni and bread-wheat improvement. To study these objectives, the substitution and genetic compensation abilities of individual T. timopheevii chromosomes for missing chromosomes of T. aestivum 'Chinese Spring' (AABBDD) were analyzed. 'Chinese Spring' aneuploids (nullisomic-tetrasomics) were crossed with a T. timopheevii x Aegilops tauschii amphiploid to isolate T. timopheevii chromosomes in a monosomic condition. The F-1 hybrids were backcrossed one to four times to Chinese Spring aneuploids without selection for the T. timopheevii chromosome of interest. While spontaneous substitutions involving all A(t)- and G-genome chromosomes were identified, the targeted T. timopheevii chromosome was not always recovered. Lines with spontaneous substitutions from T. timopheevii were chosen for further backcrossing. Six T. timopheevii chromosome substitutions were isolated: 6A(t) (6A), 2G (2B), 3G (3B), 4G (4B), 5G (5B) and 6G (6B). The substitution lines had normal morphology and fertility. The 6A(t) of T. timopheevii was involved in a translocation with chromosome 1G, resulting in the transfer of the group-1 gliadin locus to 6A(t). Chromosome 2G substituted for 2B at a frequency higher than expected and may carry putative homoeoalleles of gametocidal genes present on group-2 chromosomes of several alien species. Our data indicate a common origin for tetraploid wheat species, but from separate hybridization events because of the presence of a different spectrum of intergenomic translocations.