中文摘要：

为了研究UVB对两栖类动物早期胚胎发育的影响，以中华大蟾蜍为研究对象，用UVB分别以不同强度和不同时间照射其二细胞期胚胎，观察记录胚胎的发育过程、统计死亡率并在形态学上对UVB照射诱导的畸胚进行分析。结果表明，30μW／cm^2强度的UVB分别照射二细胞期胚胎20s、60s和80μW／cm。强度分别照射20s、60s、120s后，对中华大蟾蜍早期胚胎发育有促进作用，使发育过程中的死亡率降低，畸胚出现的类型较少且畸变程度低；80μW／cm。强度的UVB照射二细胞期胚胎600s，100μW／cm^2强度的UVB照射20s、60s、600s，120μw／cm。强度的UVB照射20s，导致胚胎发育过程中死亡率明显升高，畸胚数量多且畸变程度高。结论：UVB照射剂量和时间不同，对中华大蟾蜍早期胚胎发育的影响有明显差异。

英文摘要：

To study the effects of UVB on development of early stage embryos of amphibian, two-cell stage embryos of Bufo bufo gargarizans Cantor were irradiated by UVB with various intensity and time. The results showed that compared with control and other irradiated groups, when exposured to low intensity and short time, such as 30 μW/cm^2 in 20 s, 60 s and 80 μW/cm^2 in 20 s, 60 s, 120 s respectively, embryos development process was promoted, and embryos＇ death rate and degree of deformities were reduced. On the contrary, when irradiated by high intensity and long time, such as exposured to 80 μW/cm^2 in 600 s and 100 μW/cm^2 in 20 s, 60 s, 600 s and 120 μW/cm^2 in 20 s respectively, embryos＇ death rate increased. Then it could be concluded that various radiation intensity and time of UVB result in different effects on early stage embryos of Bufo bufo gargarizans Cantor.