Abstract Wild oat (Avena ludoviciana Durieu.) and turnipweed (Rapistrum rugosum (L.) All.) are the most important annual weed species of winter wheat (Triticum aestivum L.) in the Khorasan Razavi province of Iran. This study investigated freezing tolerance in wheat (cv. Mihan) and these two weeds based on electrolyte leakage (EL), survival (SU), regrowth characteristics and maximum photochemical efficiency of photosystem (PS) II (F'v/F'm). Significant differences in EL% at freezing temperatures were noted between these plant species. By decreasing the freezing temperatures, EL% of the leaf in all three plants was increased. The lowest and the highest temperature causing 50% EL (TEL50) of leaves belonged to wild oat (-16.6℃) and wheat (-15℃), respectively. At a temperature of -12℃, SU% of wheat and turnipweed decreased by 15% and 20% compared to the SU% at 4℃, respectively. However, the decrease in SU% in wild oat from 4℃ to -12℃ was not significant. Lethal temperature for 50% SU (LT50su) of wheat, wild oat, and turnipweed was -13.7, -14.3, and -13.5℃, respectively, and there was no significant difference between wheat and turnipweed. A general trend observed in our study was that species with higher freezing tolerance scores had a higher regrowth capacity. During the first 24 h after the freezing treatment, the F'v/F'm levels in wheat, wild oat, and turnipweed decreased by 33%, 33%, and 28%, respectively, compared to before the freezing stress. Therefore, the presence of these weeds in wheat fields after freezing stress will be possible. Under optimal conditions and lack of integrated weed management programs, these weeds, especially wild oat, will emerge, set seeds and enrich the soil seed bank and thereby continue to be a problem in the cold climates of Iran, especially in the Khorasan Razavi province. Winter weed management using tillage, non-successive planting of annual winter crops, and crop rotation will reduce the dispersal of these weeds.

中文翻译：

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与冬小麦相比，野燕麦 (Avena ludoviciana Durieu.) 和芜菁 (Rapistrum rugosum (L.) All.) 冷冻后的再生能力

摘要 野燕麦 (Avena ludoviciana Durieu.) 和芜菁 (Rapistrum rugosum (L.) All.) 是伊朗呼罗珊省最重要的冬小麦 (Triticum aestivum L.) 一年生杂草种类。本研究基于电解质泄漏 (EL)、存活 (SU)、再生特性和光系统 (PS) II (F'v/F'm) 的最大光化学效率，研究了小麦 (cv. Mihan) 和这两种杂草的抗冻性. 在这些植物物种之间注意到冷冻温度下 EL% 的显着差异。通过降低冷冻温度，所有三种植物中叶子的 EL% 都增加了。引起叶片50%EL(TEL50)的最低和最高温度分别属于野燕麦(-16.6℃)和小麦(-15℃)。在-12℃的温度下，与4℃下的SU%相比，小麦和芜菁的SU%分别降低了15%和20%。然而，野燕麦SU%从4℃降到-12℃并不显着。小麦、野燕麦和芜菁的50% SU(LT50su)致死温度分别为-13.7、-14.3和-13.5℃，小麦和芜菁无显着差异。在我们的研究中观察到的一般趋势是，具有较高抗冻性分数的物种具有较高的再生能力。在冷冻处理后的前 24 小时内，与冷冻胁迫前相比，小麦、野燕麦和芜菁中的 F'v/F'm 水平分别降低了 33%、33% 和 28%。因此，这些杂草在冷冻胁迫后存在于麦田中是可能的。在最佳条件和缺乏综合杂草管理计划的情况下，这些杂草，尤其是野燕麦，将出现、结籽并丰富土壤种子库，因此在伊朗寒冷的气候中继续成为问题，尤其是在呼罗珊拉扎维省。使用耕作、不连续种植一年生冬季作物和轮作进行冬季杂草管理将减少这些杂草的扩散。