Comparative somatic mutation dynamics in long-lived and clonally propagated chestnut trees

Long-lived trees accumulate somatic mutations during growth, making them useful for studying DNA changes over time. Chestnut (Castanea spp.) is a good model due to its longevity and clonal propagation. This study estimated mutation rates in a 130-year-old Marrone Avellinese tree and compared them with grafted clones. Results show mutations increase with growth, but grafted trees have fewer mutations, suggesting a "grafting reset effect". This highlights how grafting may limit mutation buildup and supports SNP-based tools for cultivar identification.长寿树木在生长过程中会累积体细胞突变（somatic mutation），这使其成为探究随时间推移DNA动态变化的优质研究材料。栗属（Castanea spp.）植物因其长寿特性与无性繁殖特性，成为理想的研究模型。本研究对一株130年树龄的马罗内阿韦利内塞（Marrone Avellinese）板栗植株的突变率进行了估算，并与嫁接克隆株开展了对比分析。研究结果显示，体细胞突变数量随生长进程不断增加，但嫁接植株的突变丰度更低，这提示存在"grafting reset effect"。该研究揭示了嫁接可限制突变累积的潜在机制，并为基于单核苷酸多态性（SNP，single nucleotide polymorphism）的品种鉴定工具提供了实证支持。