水稻对UV-B辐射增强的抗性遗传及其生理生化特性研究

本研究结果表明紫外线B(UVB,280～330nm)能严重影响水稻秧苗生长发育,从而引起植株矮化,叶片干枯,叶绿素含量降低,单株干物质减少甚至死亡。不同水稻基因型对紫外线的反应存在明显差异。在3个供试品种(HR、M63、Hr)中,HR最抗UVB危害。遗传分析表明水稻抗UVB的性状为数量遗传性状且受多对隐性基因控制,生化分析表明水稻秧苗经UVB处理后,在0～3d内,随着时间推移,秧苗保护酶活性明显增强,之后,保护酶活性逐惭下降,MDA含量相应增加。抗UVB品种HR比感UVB品种Hr保护酶活性一直较高,膜质过氧化程度较低,反映了保护酶对抵抗UVB危害的重要作用。

Genetics of resistance of Oryza sativa to increased UV-B radiation and its physiobiochemical characteristics

The results show that UV-B (280～330nm) radiation strongly affected the growth and development of rice (Oryza sativa) seedlings, and thus, induced dwarf plants, wilted leaves, decreased chlorophyll content and dry matter of individual plants, and even death. The response of different rice genotypes to UV-B radiation was quite different. Among the three tested rice cultivars (HR, M63 and Hr), HR had the best resistance to UV-B radiation. The genetic analysis indicates that the resistance of rice UV-B radiation was the quantitative genetic trait mainly controlled by recessive polygenes. The biochemical analysis demonstrates that the activity of protective enzymes in rice seedlings treated with UV-B radiation significantly increased within 0～3days, then decreased gradually, and the content of malondialhyde (MAD) consequently enhanced. The resistant cultivar HR had a higher activity of protective enzymes than sensitive Hr, but a lower extent of lipid peroxidation, implying that the protective enzymes played an important role in resistance to UV-B radiation.