State Key Laboratory of Crop Genetics and Germplasm Enhancement, Cytogenetics Institute, Nanjing 210095, China.
Henan Academy of Crop Molecular Breeding, Henan Academy of Agricultural Sciences/Key Laboratory of Oil Crops in Huang-Huai-Hai Plains, Ministry of Agriculture/Henan Provincial Key Laboratory for Oil Crops Improvement, Zhengzhou, Henan 450002, China.
Genome. 2022 Apr;65(4):205-217. doi: 10.1139/gen-2021-0074. Epub 2021 Dec 16.
Modern hexaploid wheat ( L.; AABBDD) has evolved from a hybrid of tetraploid wheat (closely related to L. ssp. (Desf.) Husn., AABB) and goatgrass ( Coss., DD). Variations in chromosome structure and ploidy have played important roles in wheat evolution. How these variations occur and their role in expanding the genetic diversity of modern wheat remain largely unknown. Synthetic hexaploid wheat (SHW) can be used to investigate chromosome variations that occur during the early generations of existence. SHW lines derived by crossing durum wheat 'Langdon' with 12 accessions were analyzed using oligonucleotide probe multiplex fluorescence in situ hybridization (FISH) of metaphase chromosomes and SNP markers. Cluster analysis based on SNP markers categorizes them into three groups. Among 702 plants from the S and S generations, 415 (59.12%) carried chromosome variations involving all 21 chromosomes, but with different frequencies for each chromosome and sub-genome. Total chromosome variation frequencies varied between lines, but there was no significant difference among the three groups. The non-random chromosome variations in the SHW lines detected in this study may indicate that similar variations occurred in the early stages of wheat polyploidization and played important roles in wheat evolution.
现代六倍体小麦（ L.；AABBDD）是由四倍体小麦（与 L. ssp. (Desf.) Husn.，AABB 密切相关）和山羊草（ Coss.，DD）杂交进化而来的。染色体结构和倍性的变化在小麦进化中发挥了重要作用。这些变化是如何发生的，以及它们在扩展现代小麦遗传多样性方面的作用在很大程度上仍然未知。合成六倍体小麦（SHW）可用于研究早期存在过程中发生的染色体变异。通过用硬粒小麦 'Langdon'与 12 个品系杂交获得的 SHW 系，使用中期染色体寡核苷酸探针多重荧光原位杂交（FISH）和 SNP 标记进行了分析。基于 SNP 标记的聚类分析将它们分为三组。在 S 和 S 世代的 702 株植物中，有 415 株（59.12%）携带涉及所有 21 条染色体的染色体变异，但每条染色体和亚基因组的频率不同。各系间总染色体变异频率不同，但三组间无显著差异。本研究在 SHW 系中检测到的非随机染色体变异可能表明，在小麦多倍化的早期阶段发生了类似的变异，并在小麦进化中发挥了重要作用。
