Pahkala Maarit, Laurila Anssi, Merilä Juha
Department of Population Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18d, SE-752 36, Sweden.
Oecologia. 2002 Dec;133(4):458-465. doi: 10.1007/s00442-002-1058-6. Epub 2002 Dec 1.
Interspecific variation in ultraviolet-B (UV-B) radiation tolerance in amphibians is well established, but little is known about the possible intraspecific variation in UV-B radiation tolerance within any species. We studied the effects of UV-B radiation on common frog Rana temporaria embryos originating from eight populations spanning a 1,200 km latitudinal gradient across Sweden. Newly fertilised eggs were exposed to three different UV-B treatments [absent (no UV-B), normal (1.254 kJ m) and enhanced (1.584 kJ m, 26% above normal) levels] in a laboratory, and effects on survival, frequency of developmental anomalies, developmental rate and hatchling size were documented. UV-B radiation treatments did not have main factor effects on embryonic mortality or frequency of developmental anomalies. Survival to hatching was lower at higher latitudes, but it was independent of UV-B treatments. High UV-B treatment prolonged development time in five populations, whereas in one population development time was longest in the absence of UV-B. Even though the northernmost populations had the shortest development times, the interaction between latitude and development time was not significant. There was a significant population×UV-B interaction in hatchling size, indicating that hatchling size was negatively affected by the UV-B treatments in some of the populations. Hatchling size increased until mid-latitudes and was again somewhat smaller at the northernmost latitudes, but this was independent of UV-B treatments. These results suggest that although R. temporaria embryos are rather tolerant of UV-B radiation, and there is no clear latitudinal pattern to UV-B tolerance in this species, the sublethal effects of UV-B on embryonic development may differ among different populations.
两栖动物对紫外线B（UV-B）辐射耐受性的种间差异已得到充分证实，但对于任何物种内UV-B辐射耐受性可能存在的种内差异却知之甚少。我们研究了UV-B辐射对源自瑞典境内跨越1200公里纬度梯度的8个种群的普通青蛙（林蛙）胚胎的影响。在实验室中，将新受精的卵暴露于三种不同的UV-B处理条件下[无（无UV-B）、正常（1.254千焦/平方米）和增强（1.584千焦/平方米，比正常水平高26%）水平]，并记录了对存活率、发育异常频率、发育速率和幼体大小的影响。UV-B辐射处理对胚胎死亡率或发育异常频率没有主要影响。在较高纬度地区孵化的存活率较低，但这与UV-B处理无关。高UV-B处理延长了5个种群的发育时间，而在1个种群中，在无UV-B的情况下发育时间最长。尽管最北部的种群发育时间最短，但纬度与发育时间之间的相互作用并不显著。幼体大小存在显著的种群×UV-B相互作用，表明在某些种群中，UV-B处理对幼体大小有负面影响。幼体大小在中纬度地区之前增加，在最北部的纬度地区又有所减小，但这与UV-B处理无关。这些结果表明，尽管林蛙胚胎对UV-B辐射具有相当的耐受性，并且该物种的UV-B耐受性没有明显的纬度模式，但UV-B对胚胎发育的亚致死效应在不同种群之间可能存在差异。
