辐射诱导荆州黑麦染色体1R结构变异的研究

以60Co γ射线(12Gy)辐照普通小麦辉县红-荆州黑麦染色体1R二体添加系花粉,并授粉给辉县红,获得153粒辐射杂种M₁代种子。以Fluorescein-12-dUTP标记的荆州黑麦基因组DNA为探针,对其中33粒M₁代种子根尖细胞有丝分裂中期染色体进行GISH(genomic in situ hybridization)分析发现,23粒种子中的荆州黑麦1R染色体未发现明显变化,而另外10粒均发生了小麦和黑麦染色体易位,变异率为30.30%。电离辐射诱发产生的易位类型包括相互易位、大片段易位、小片段易位、整臂易位及端体等。这些易位染色体涉及1R染色体11个易位断点,其中位于长臂4个,短臂6个,位于着丝粒区1个,说明电离辐射可有效诱发目标染色体系列结构变异,为染色体缺失作图、重要性状基因定位和培育仅具目标基因的小片段易位提供了可能。

STRUCTURAL VARIATIONS OF CHROMOSOME 1R FROM RYE CULTIVAR JINGZHOUHEIMAI INDUCED BY IRRADIATION

Irradiated with 60Co γ-rays (12Gy), the pollen of wheat landrace Huixianhong-Secale cereale cv. Jingzhouheimai DA1R was pollinated to the emasculated spikes of Huixianhong. Analyzed with genomic in situ hybridization GISH using gDNA of rye cv. Jingzhouheimai as a probe, four plants with reciprocal translocation, four plants with large segmental translocation and one plant with distal segmental translocation, one plant with one telocentric chromosome were identified from 33 M1 seeds. The results showed that the translocation frequency was 30.30% and of the total 11 breakage-fusion events, 1 involved centric regions and 10 involved interstitial regions, The experiment showed that pollen irradiation was an effective method to induce wheat alien chromosomal structural variations, which could effectively be used in deletion mapping, chromosomal location of important agronomic genes and development of small segmental translocations with target genes.