Monitoring viability loss of seeds conserved ex situ for timely germplasm regeneration is a challenging task in germplasm management and conservation as the process of seed deterioration under long-term storage remains poorly understood and effective tools for assessing seed deterioration are lacking. This paper reports findings from four experiments that were aimed to study the fragmentation of mitochondrial DNA (mtDNA) due to degradation in naturally or artificially aged (NA or AA) wheat seeds. Together, it was found that mtDNA fragmentation occurred in aged wheat seeds. More mtDNA fragmentation was observed in AA than NA seeds and degradation was more prominent in abnormal seedling tissues than in normal seedling tissues. Fragmentation of mtDNA was linearly associated with sample germination; more in less viable seed samples. Mitochondria (mt) in aged seeds were found to break throughout the mitochondrial genome with the observed loss of PCR amplification of atp1-5, nad4.2, atp4, and nad9 gene loci and at the roughly 80 kb repetitive region. These findings are useful for understanding the process and involvement of mtDNA degradation in NA or AA wheat seeds and for further exploration to develop aging biomarkers for monitoring seed viability.

在种质管理和保存中，监测在异地保存的种子的生存能力丧失，以进行及时的种质更新是一项艰巨的任务，因为人们对长期保存下的种子退化过程仍然知之甚少，并且缺乏评估种子退化的有效工具。本文报告了四个实验的发现，这些实验旨在研究由于自然或人工老化（NA或AA）小麦种子降解而引起的线粒体DNA（mtDNA）片段化。在一起，发现在老化的小麦种子中发生了mtDNA片段化。在AA中观察到比NA种子更多的mtDNA片段化，并且在异常幼苗组织中的降解比在正常幼苗组织中更明显。mtDNA断裂与样品萌发呈线性关系；在不太可行的种子样品中更多。ATP1 - 5，nad4.2，atp4，和的nad9基因位点，并在大约80 kb的重复区。这些发现对于了解NA或AA小麦种子中mtDNA降解的过程和参与以及进一步探索开发老化的生物标记物以监测种子生存力很有用。