The mantled phenotype in oil palm is a somaclonal variant that can only be visibly detected when the plant reaches reproductive maturity, which is typically 2 to 3 yr after planting in the field. This phenotype is linked to the Bad Karma epiallele, which involves reduced methylation of the Karma retrotransposon in the EgDEF1 gene. In this study, Karma-EgDEF1 methylation was examined in clonal mother palms (clonal ortets) that were phenotypically normal, but upon clonal propagation, produced high mantling rates in their reclones. These clonal ortets were clones of a seed-derived ortet. Single-nucleotide methylation analysis identified two hypomethylated regions located in the mid-Karma region of the high-mantling clonal ortets. One of these regions is located next to the RsaI methylation feature within Karma in mantled clones. This is the first report of such an event in oil palm clonal propagation, where almost all clonal ortets cloned from a seed-derived ortet produced high mantling rates in their reclones, representing a significant economic risk. The differentially methylated regions identified in this study could serve as potential methylation markers for screening high-risk clonal ortets, which merits further investigations.

油棕中的披覆表型是一种体细胞克隆变体，只有当植物达到生殖成熟时才能明显检测到，通常是在田间种植后 2 至 3 年。这种表型与Bad Karma表观等位基因有关，该表型涉及EgDEF1基因中Karma逆转录转座子的甲基化减少。在这项研究中，Karma - EgDEF1甲基化在表型正常的克隆母棕榈（克隆 ortets）中进行了检查，但在克隆繁殖后，在其再克隆中产生了较高的覆盖率。这些克隆 ortet 是种子衍生的 ortet 的克隆。单核苷酸甲基化分析确定了位于高曼特克隆 ortets中部Karma区域的两个低甲基化区域。这些区域之一位于mantled 克隆中Karma内 RsaI 甲基化特征旁边。这是油棕克隆繁殖中此类事件的首次报告，几乎所有从种子衍生的 ortet 克隆的克隆 ortet 在其再克隆中都产生了很高的覆盖率，代表着重大的经济风险。本研究中确定的差异甲基化区域可以作为筛选高风险克隆ortets的潜在甲基化标记，值得进一步研究。