【作者】 尹淑霞；

【导师】 韩烈保；

【作者基本信息】 北京林业大学 ， 森林培育， 2005， 博士

【摘要】 为探讨空间飞行和γ射线辐射对草坪草的诱变效应,本研究对多年生黑麦草（Lolium perenne L.）超级德比（Derby Supreme）的干种子分别搭载于“神舟四号”飞船进行空间飞行和不同剂量的⁶⁰Co—γ射线辐射处理,而后与对照种子在室内进行种子发芽试验、在田间进行幼苗生长观察,通过聚丙烯酰胺垂直电泳技术对处理种子F1代植株的过氧化物酶同工酶（POD）和酯酶同工酶（EST）进行分析,利用AFLP分子标记技术对处理种子F1代植株进行DNA突变效应的检测,从种子萌发、幼苗生长特征、同工酶和DNA水平上研究空间飞行和γ射线辐射对多年生黑麦草的诱变效应。 种子发芽试验结果表明,空间飞行可提高种子发芽势和种子活力,但会降低种子发芽率。低剂量辐射对种子萌发无显著影响。随着辐射剂量的增加,对种子萌发的抑制作用增强。 田间播种后30d分别测量不同处理的植株生长高度和分蘖枝数,结果表明,经空间飞行的种子F1代植株总体上比对照材料高,株高变异幅度大,植株分蘖枝数也比对照材料多。辐射剂量为50Gy的材料,株高的分布区间与对照相近,但分蘖枝数比对照材料多。随着辐射剂量的加大,植株高度及分蘖枝数呈下降趋势。 同工酶分析结果表明,不同处理材料的POD同工酶酶谱有一定差异,空间飞行处理的材料比对照增加了2条谱带,辐射剂量为150Gy的材料则出现了一条特征带。EST同工酶分析结果表明,空间飞行和辐射剂量为150Gy的材料与对照EST酶谱相近,但酶活性的强弱有一定变化。其他处理材料的酶带与对照相比均出现增加或缺失。 AFLP指纹分析图谱表明,不同处理材料在DNA水平上均发生了较大的变异。其中,辐射剂量150Gy的材料的平均变异率最高,达到27.8%,其次是空间飞行材料,平均变异率为24.97%,最低的是辐射剂量100Gy的材料,其平均变异率为18.19%。各材料间遗传距离范围在0.109～0.226。在辐射处理中,随辐射剂量加大,对种子萌发和幼苗生长抑制作用增强,但其DNA变异率并没有这种变化趋势。根据AFLP指纹图谱进行的聚类分析表明,7份材料可聚为4类,即对照、辐射剂量为50Gy、100Gy和300Gy的材料为一类,辐射剂量为200Gy、空间飞行及辐射剂量150Gy各自成一类。 本研究结果表明,空间飞行及不同辐射剂量的⁶⁰Co—γ射线辐射处理,在多年生黑麦草超级德比的种子萌发、幼苗生长、植株同工酶和DNA水平上均发生一定的变化,特别是在DNA水平上证明了不同处理材料的基因发生了突变,为空间诱变和辐射诱变技术在多年生黑麦草育种中的应用提供了理论依据。更多还原

【Abstract】 In order to inquire the mutagenic effects of space flight and gamma rays radiation on turfgrass, the dry seeds of perennial ryegrass(Lolium perenne L.) variety Derby Supreme were flied in space carried by SZ-4 spaceship and radiated by 60~Co gamma rays with different doses in this paper. The treated and CK’s seeds were germinated indoors and planted in fields, respectively, to learn their differences in seeds germination and seedlings growth, then POD and EST isozymes of plants were analyzed through PAGE, and the DNA mutation effects of plants were checked by AFLP fingerprintings. That was, the mutation effects of space flight and gamma rays radiation on seeds of perennial ryegrass were probed through four aspects, including seeds germination, seedlings growth, isozymes and DNA level.The results of seeds germination showed that space flight could improve seeds germination power and seeds vigor, but seeds germination rate declined. With regard to the radiation, low dose of gamma rays had no obvious effects on the seeds germination. With the increase of radiation dose, the seeds germination was depressed.The plants height and tillers number were measured and investigated after planting 30 days in fields. The results showed that the height of plants that seeds flied in space were taller than CK plants in general, and the variation of plants height was broader and there were more tillers in plants. The distribution interval of tillers number of 50Gy gamma rays plants was similar to CK plants, but there were more tillers than CK. Also, with the increase of radiation dose, the plants height and tillers number descended.The isozymes analysis showed that there were some differences among different treated materials in zymogram patterns of POD isozymes. Comparing to CK plants, there were 2 POD bands more in plants that seeds flied in space and a special band in plants of 150Gy gamma rays radiation. The results of EST analysis showed that EST patterns of plants that seeds flied in space and radiated by 150Gy gamma rays were similar to CK, but there were some differences in the vigor of isozymes. The EST bands were added or absent in other treated materials compared to CK.The analysis of AFLP fingerprinting showed that there were more differences among different treated materials in DNA level. The highest average mutation percentage was 27.8% in the plants that seeds radiated with 150Gy Gamma rays, the next was the plants that seeds flied in space, which the average mutation percentage was 24.97%, and the lowest one was 18.19% in the plants that seeds radiated with l00Gy Gamma rays. The genetic distance of all materials ranged between 0.109 and 0.226. Regard to the radiation,the seeds germination and seedling growth were depressed with the increase of Gamma rays dose, however, this trend were not approved by the DNA mutation percentage. According to the AFLP fingerprinting, 7 materials could be clustered to 4 groups, that was, CK, materials that seeds radiated by Gamma rays with 50Gy, lOOGy and 300Gy doses were in the same group, other materials including seeds radiated by Gamma rays with 200Gy, 150Gy doses and flied in space were in different groups, respectively.Based on the analysis of seeds germination, seedlings growth, isozymes and DNA mutation, mutagenic effects of space flight and Gamma rays radiation on dry seeds of perennial ryegrass Derby Supreme were proved, which provided the theoretic proofs for the applications of space flight and gamma rays radiation on perennial ryegrass breeding.更多还原