模拟UV-B辐射增强条件下灯盏花居群的生理差异及其遗传背景

Physiological differences and their genetic backgrounds of Erigeron breviscapus populations under enhanced UV-B radiation

在温室条件下,研究了模拟UV-B辐射(280～320nm)增强对6个灯盏花居群的类黄酮、丙二醛(MDA)含量和抗氧化酶活性的影响及其种内差异,并利用ISSR分子标记技术对灯盏花居群进行遗传背景分析.结果表明:在UV-B辐射增强条件下,灯盏花D01、D53、D63和D65居群在成苗期、盛花期和成熟期的类黄酮含量均显著增加,成苗期与盛花期MDA含量显著降低;而D47和D48居群3个生育期的MDA含量和盛花期类黄酮含量均显著增加,成熟期显著降低.D01居群3个生育期的POD、APX活性,成苗期、盛花期CAT活性与盛花期SOD活性均显著升高;D47居群3个生育期的SOD、CAT和APX活性,成熟期POD活性显著下降;D48居群3个生育期的POD、APX活性,成苗期、成熟期的SOD活性均显著下降;D53居群成苗期和盛花期SOD、APX活性,盛花期CAT活性显著增加;D63居群3个生育期的SOD、POD和APX活性均显著上升;D65居群除成熟期的CAT和APX活性没有显著变化外,3个生育期的4种抗氧化酶活性均显著上升.灯盏花居群对UV-B辐射增强的响应有明显的种内差异,D01、D53、D63和D65为UV耐性居群,而D47和D48居群的UV敏感性较高.灯盏花居群不同生育期对UV-B辐射的响应为盛花期>成苗期>成熟期.居群间的遗传多样性差异明显,在遗传距离为0.11的水平上,可将D01、D53、D63和D65居群归为一类,D47和D48居群为另一类,这与根据生理响应指数判断的UV耐性与敏感居群的结果基本一致.

A simulation experiment was conducted under greenhouse condition to study the effects of enhanced UV-B radiation （280-320 nm） on the flavonoid and MDA contents and antioxidant enzyme activities of six Erigeron breviscapus populations,and the intraspecific differences in physiology to the UV-B radiation. The related genetic backgrounds of E. breviscapus populations were also analyzed by ISSR analysis. Under enhanced UV-B radiation,the flavonoid content of E. breviscapus populations D01,D53,D63 and D65 increased significantly at seedling,flowering,and maturing stages,and the MDA content decreased significantly at seedling and flowering stages; while the flavonoid content of D47 and D48 increased significantly at flowering stage but decreased at maturing stage,and the MDA content increased significantly at the three growth stages. The POD and APX activities of D01 at the three growth stages,CAT activities at seedling and flowering stages,and SOD activity at flowering stage significantly increased; the SOD,CAT and APX activities of D47 at the three growth stages and the POD activity at maturing stage decreased significantly; the POD and APX activities of D48 at the three growth stages and the SOD activity at seedling and maturing stages decreased significantly; the SOD and APX activities of D53 at seedling and flowering stages and the CAT activity at flowering stage increased significantly; the SOD,POD and APX activities of D63 at the three growth stages increased significantly; and the CAT and APX activities of D65 at maturing stage had no significant changes,but the test enzyme activities at the three growth stages increased significantly. D01,D53,D63,and D65 were tolerant to UV-B radiation,while D47 and D48 were sensitive to UV-B radiation. The responses of E. breviscapus populations to enhanced UV-B radiation varied with growth stage,being in the order of flowering stage 〉seedling stage 〉maturing stage. There was an obvious genetic polymorphism among the six E. breviscapus populations,which were divided into two groups at the level of 0.11 of genetic distance,one group including D01,D53,D63 and D65,and the other including D47 and D48. This classification was consistent with the results of physiological response index to UV-B radiation.