荧光原位杂交（Fluoresence in situ hybridization, FISH）是研究染色体变异的有力工具。本研究基于本实验室开发的寡核苷酸探针套#4（Oligonucleotide probe multiplex#4，ONPM#4）进行FISH分析，结合A基因组寡核苷酸探针开发，分析了人工合成小麦、小麦祖先种和小麦-百萨偃麦草异染色体系中染色体演化特征，主要结果如下： 首先，通过对栽培一粒小麦基因组测序和生物信息学分析，设计了6条寡核苷酸探针，发现这些序列在不同物种中信号数目、分布位置均存在明显差异；同时，利用小麦45S rDNA序列，设计了包含9条寡核苷酸探针的45S rDNA探针套，可以清晰区分小麦及粗山草随体染色体；研究还利用新开发的百萨偃麦草串联重复序列寡核苷酸探针BS-HC CL135-2，与前期开发探针结合，可以清晰区分不同节节麦染色体多态性，确定不同来源节节麦间1D ~ 7D染色体。 其次，利用ONPM#4对13份衍生自硬粒小麦Langdon和不同节节麦的人工合成小麦F8代植株染色体组成进行了分析，发现不同来源节节麦染色体间存在丰富多态性。共发现30种多态类型，其中2D、4D和6D均为5种，5D最多为6种，1D有4种，3D有3种，7D有2种。进一步对13个系301个F8单株（每个系分析5 ~ 40个单株）分析发现，49.17%的单株涉及染色体变异，但不同系间差异明显，变幅为8.33% ~ 100%。对变异染色体分析表明，B基因组染色体变异频率最高（32.89%），其次为D（16.28%)，A最小（15.95%）；21条染色体而言，有20条涉及变异，其中1B变异频率最高（18.27%），从高到低依次为：4B（6.64%）、5A（5.98%）、1D = 4D（5.65%）、4A（3.65%）、1A（3.32%）、7B（2.66%）、3D（1.99%）、5B = 6B = 2D（1.66%）、2A = 6A = 2B = 3B = 6D（1.00%）、3A（0.66%）、7A（0.33%）、5D（0.33%），而7D未发生明显变异。 再者，利用ONPM#4对12个小麦近缘种和2个栽培品种进行分析发现，自然加倍形成的四倍体小麦AABB中，相比于原始的A基因组和S基因组，A和B基因组均发生了大量重复序列变化，两者不同程度的丰富了彼此信号，但在普通小麦第二次远缘杂交和加倍过程，A和B组染色体重复序列变化不大，而且新加入的D基因组染色体与祖先种节节麦相比差异亦不明显。 最后，利用ONPM#4 FISH结合基因组GISH（Genomic in situ hybridization）分析，将中国春-百萨偃麦草易位系T2JS-2BS·2BL回交转移进扬麦6号、烟农19和矮苏三等3个不同栽培品种，并获得农艺性状显著改良的9个小麦种质，T2JS-2BS·2BL的引入显著增加了株高和穗长并明显改善了种质穗发芽抗性，将矮苏三株高平均提高了16.45cm，千粒重提高了9.84g，为小麦育种提供了新的矮秆多穗抗穗发芽种质。

Fluoresence in situ hybridization (FISH) is a powerful tool for studying chromosome variation. FISH using oligonucleotide probe multiplex #4 (ONPM#4) developed by our laboratory and A genome oligonucleotide probes developed in this study was used to analyze chromosomal evolution of synthetic wheat, wheat ancestors and wheat-Thinopyrum bessarabicum chromosome translocations. The main results are as follows: Firstly, six oligonucleotide probes were designed by sequencing and bioinformatics analysis of Triticum monococcum genome. By FISH, significant variations of the signal number and distribution positions in different species were observed. The 45S rDNA sequence of wheat was dissected into 9 oligonucleotide probes and formed a multiplex probe for distinguishing the satellite chromosomes of wheat and Aegilops tauschii. Additionally, a tandem repeat oligonucleotide probe BS-HC CL135-2 which was newly developed using Thinopyrum bessarabicum genomic sequences was combined with the pre-developed probes for corresponding polymorphic chromosomes of different Aegilops tauschii accessions. Secondly, the chromosome composition of 13 Synthetic wheat (SW) lines derived from durum wheat Langdon and different Aegilops tauschii was analyzed by ONPM#4. It was found that there were abundant polymorphisms between the chromosomes of different D genome sources. A total of 30 polymorphic types were found including 5 for each of 2D, 4D and 6D, 6 for 5D, 4 for 1D, 3 for 3D, and 2 for 7D. Further analysis of 301 individual F8 plants from 13 SW lines (5 to 40 individuals for each line) showed that 49.17% of plants involved chromosomal variations, but the frequency varied in different lines, ranging from 8.33% to 100%. According to the analysis of variant chromosomes, the variation frequency of B genome is the highest (32.89%), followed by D (16.28%) and A (15.95%); For 21 pairs of chromosomes, 20 pairs involved variations, of which 1B had the highest frequency of variation (18.27%), followed by 4B (6.64%), 5A (5.98%), 1D = 4D (5.65%), 4A (3.65%), 1A(3.32%), 7B (2.66%), 3D (1.99%), 5B = 6B = 2D (1.66%), 2A = 6A = 2B = 3B = 6D (1.00%), 3A (0.66%), 7A (0.33%), 5D (0.33%) and no significant variation in 7D was found. Thirdly, using ONPM#4, 12 wild species of wheat and 2 cultivars was analyzed, obvious variations of repeat sequences were found in both A and B genomes in tetraploid wheat (AABB) in comparison with the original A and S genomes. However, in the second distant hybridization between AABB and DD, no obvious changes in A and B genome chromosome were found in comparison with the D genome chromosomes of Aegilops tauschii and AABB of tetraploid wheat. Finally, using ONPM#4 FISH combined with GISH (Genomic in situ hybridization), Chinese Spring - Thinopyrum bessarabicum translocation T2JS-2BS·2BL was transferred into three different cultivars Yangmai 6, Yannong 19 and Aisu 3 by backcrossing. Nine wheat lines with promise agronomic traits were obtained and identified. The introduction of T2JS-2BS·2BL significantly increased plant height, spike length and preharvest sprouting resistance. The average height of Aisu 3 was increased by 16.45 cm and 1000 kernel weight by 9.84 g, which provided new germplasm for breeding wheat with reduced plant height, more spikes and higher preharvest sprouting resistance.