小偃麦异代换系山农0095辐照花粉后代的细胞学及SSR标记分析

CYTOLOGICAL AND SSR ANALYSIS OF IRRADIATION-INDUCED PROGENIES OF TRITITRIGIA SUBSTITUTION LINE SN0095

本研究采用60Co-γ射线辐照小偃麦异代换系山农0095花粉,对其M1、M2代的细胞遗传学特点进行分析,结果表明:M1、M2代均出现频率不同和染色体数目不等(2n=41、2n=40和2n=39)的染色体数目变异类型;在两个世代的花粉母细胞减数分裂过程中,普遍观察到单价体、多价体、染色体片段、落后染色体、染色体桥及微核等现象,说明辐射有效地促进了染色体数目和结构的改变,有可能导致染色体易位重组。利用已建立的山农0095中中间偃麦草染色体的特异SSR标记BARC159240对M2代进行检测,结果发现大部分M2单株仍含有该标记位点,说明这些植株仍然具有标记位点的中间偃麦草染色体特异区段;少部分单株虽然保留了该位点,但缺少普通小麦中的条带,这些单株可能发生了染色体重组。

Pollens of Trititrigia substitution line SN0095 were radiated with ^60Co-γ ray and cytological characters of the progenies M1 and M2 were studied. The results showed that variations with different frequencies and chromosome numbers （2n=41, 2n=40 and 2n=39） were observed in both M1 and M2. Abnormal phenomena, such laggard as univalents, multivalents, chromosome fragments, chromosomes, chromosome bridges and micronucleus, appeared in high frequencies during the meiosis. It suggested that irradiation could promote changes of chromosome number and configuration efficiently, and could lead to rearrangements or translocations between chromosomes. The M2 progenies were examined using BARC159240, a Thinopyrum inter medium-specific SSR marker of SN0095. Most M2 plants carried the locus BARC159240, which indicated that the specific segment involving the locus BARC159240 of Thinopyrum intermedium existed in these plants. However, a band of common wheat YN15 disappeared in a few plants although the locus BARC159240 existed, which implied that chromosome rearrangements may have occurred in these plants.