The long‐term contamination that followed the nuclear disaster at Chernobyl provides a case study for the effects of chronic ionizing radiation on living organisms and on their ability to tolerate or evolve resistance to such radiation. Previously, we studied the fertility and viability of early developmental stages of a castrating plant pathogen, the anther‐smut fungus Microbotryum lychnidis‐dioicae, isolated from field sites varying over 700‐fold in degree of radioactive contamination. Neither the budding rate of haploid spores following meiosis nor the karyotype structure varied with increasing radiation levels at sampling sites. Here, we assessed the ability of the same M. lychnidis‐dioicae strains to perform their whole life cycle, up to the production of symptoms in the plants, that is, the development of anthers full of fungal spores; we also assessed their viability under experimental radiation. Fungal strains from more contaminated sites had no lower spore numbers in anthers or viability, but infected host plants less well, indicating lower overall fitness due to radioactivity exposure. These findings improve our understanding of the previous field data, in which the anther‐smut disease prevalence on Silene latifolia plants caused by M. lychnidis‐dioicae was lower at more contaminated sites. Although the fungus showed relatively high resistance to experimental radiation, we found no evidence that increased resistance to radiation has evolved in populations from contaminated sites. Fungal strains from more contaminated sites even tolerated or repaired damage from a brief acute exposure to γ radiation less well than those from non‐ or less contaminated sites. Our results more generally concur with previous studies in showing that the fitness of living organisms is affected by radiation after nuclear disasters, but that they do not rapidly evolve higher tolerance.

中文翻译：

---

来自切尔诺贝利污染更严重的部位的花药曲霉真菌在实验照射后显示出较低的感染能力和较低的生存力。

切尔诺贝利核灾难之后的长期污染为长期电离辐射对活生物体的影响及其对此类辐射的耐受性或抵抗能力提供了案例研究。以前，我们研究了cast割植物病原体花药曲霉菌Microbotryum lychnidisdioicae的早期发育阶段的肥力和生存力，这些病原菌是从放射性污染程度变化超过700倍的田间地点中分离出来的。减数分裂后单倍体孢子的出芽率和核型结构都没有随采样点辐射水平的增加而变化。在这里，我们评估了相同的M. lychnidis‐dioicae的能力在整个植物生命周期中直至植物产生症状的菌株，即充满真菌孢子的花药的发育；我们还评估了它们在实验辐射下的生存能力。来自受更多污染的部位的真菌菌株的花药或存活率没有降低的孢子数量，但被感染的寄主植物效果欠佳，表明由于放射性暴露而降低了总体适应性。这些发现提高了我们对以前田间数据的了解，在该数据中，由M. lychnidis-dioicae引起的阔叶莲属植物的花药病发病率高在受污染较严重的地方较低。尽管真菌对实验辐射表现出相对较高的抵抗力，但我们没有发现证据表明受污染场所的种群对辐射的抵抗力有所提高。来自较受污染的部位的真菌菌株甚至耐受或修复的短暂急性暴露于γ射线所造成的损害要比未受污染或污染较少的部位的真菌菌株好。我们的研究结果与先前的研究大体上一致，前者表明核灾难后辐射会影响生物体的适应能力，但它们并不能迅速发展出更高的耐受性。