黑麦端部特异重复序列pSc200在新合成的不同小麦-黑麦双二倍体中的变异

Variation of Rye-Specific Telomeric Tandem Repeat pSc200 in Newly Synthesized Wheat-Rye Amphiploids

【目的】更好地了解在小麦-黑麦双二倍体形成过程中,黑麦染色体变异的情况。【方法】利用黑麦Kustro及黑麦AR106BONE分别与小麦品种绵阳11杂交,获得两种双二倍体(MKS1及MARS1)。以黑麦亚端部串联重复序列pSc200为探针,采用荧光原位杂交的方法,分析亲本黑麦及相应的双二倍体中黑麦染色体端部染色体结构变化。【结果】检测到pSc200杂交位点在MKS1中减少,而在MARS1中增加。【结论】异源多倍体化过程中,染色体端部结构的变异是伴随多倍体化快速发生的。这可能有利于新合成的异源多倍体快速稳定,使得两个不同的基因组在同一核中协调共存。来自不同组合的小麦-黑麦双二倍体中,黑麦染色体结构发生不同的变异为黑麦在小麦育种中的应用提供了启示。

[ Objective ] Structural variation of rye chromosomes during the formation of wheat-rye amphiploids was analyzed for better application of rye in wheat breeding. [Method] Two kinds of wheat-rye amphiploids, MKSI and MARSI, were derived from Triticum aestivum Mianyangl 1 xSecale cereale Kustro and Triticum aestivum Mianyangll ~Secale cereale AR106BONE, respectively. Fluorescence in situ hybridization （FISH） analysis was applied using pSc200, a rye-specific subtelomeric tandem repeat as probe. [Result] FISH sites of pSc200 decreased in MKS1, but expanded in MARS1, comparing with their parental rye. [Conclusion] Allopolyploidy in wheat-rye can be accompanied by immediate structural variation oftelomere, which presumably play a role in the initial stabilization of the nascent amphiploid plants and in coordination between the constituent genomes. Different variation of rye chromosomes in different amphiploids gives inspiration for breeders to utilize rye germplasm in wheat breeding.