Co^(60)-γ辐射对2种高羊茅染色体核型的影响

Effects of Co^(60)-γ Radiation on the Chromosome Karyotypes of Two Festuca arundinace Cultivars

以2种高羊茅(Festuca arundinace)为材料,用Co^(60)-γ射线为照射源辐照干种子,辐射剂量分别为0 Gy、100 Gy、200Gy、300 Gy,采用染色体常规压片方法对辐射处理材料的染色体数目及核型进行了初步研究,结果表明:1)对照组2个品种的染色体数目均相同(2n=42),均属于大染色体,但在核型组成上存在一定的差异,多数染色体为中部着丝粒,核型多为对称型。2)同一品种高羊茅在不同剂量辐射下染色体核型存在差异,而相同剂量辐射下不同品种染色体结构变化也存在差异。3)辐射后的高羊茅染色体数目发生了变化,出现40条和42条两种情况。4)核型类型有3种,分别为:2B、2C和1B。5)组成结构大多都为中部染色体和近中部染色体,少数有正中部染色体或者近端部染色体,极少数出现了小染色体和随体。本文从染色体水平上进行研究,旨在为草坪草种质资源的研究和利用提供细胞遗传学依据。

The seeds of two Festuca arundinace cultivars were radiated by Co60y/rays with 0 Gy, 100 Gy, 200 Gy and 300 Gy radiation doses, and the chromosome number and karyotype of these two cultivars and radiated lines were investigated by using histological sectioning technique. The results showed that the two varieties possessed the same chromosome number （2n=42） belonging to macrochromosome but exhibited some differences in the compo- nents of karyotype. The most chromosomes of the two varieties were metacentric and most of the karyotype was sym- metric. The chromosome karyotype of the radiated lines by different doses of radiation showed differences for each individual Festuca arundinace cuhivar, and chromosome structure changes were also observed in the different lines by the same doses of radiation. After radiation, change of the chromosome number n=40 and n=42 were found in the radiated lines. There were three karyotypes 2B, 2C and 1B found in the lines. Central and near central chromosomes were mostly found in the composition structure of karyotype and only a few had middle or near the end chromosomes, very few small chromosome and satellite were detected. Our results provide some information at the chromo- some level for the future germplasm resources research and utilization of the turfgrass.