Mutation in focus: first record of a wild chimeric individual for the subtribe Laeliinae (Orchidaceae)

ABSTRACT Variegated species are highly appreciated for their unique aesthetics. Although often confused, variegation and chimerism are distinct phenomena. Chimerism can also cause variation in the color of plant organs, but it is a specific type of genetic mosaic. Limited information is available on variegation and chimerism in Orchidaceae. Here, the first record of a wild foliar chimeric mutant for the subtribe Laeliinae (Orchidaceae) is presented. In July 2020, a sterile chimeric individual of Epidendrum cinnabarinum was found and photographed in a fragment of restinga in the Área de Proteção Ambiental das Lagoas e Dunas do Abaeté, a conservation unit in the municipality of Salvador in the state of Bahia, Northeast Brazil. The plant's phenotype is a mosaic of green, cream and yellow striped leaves in different proportions. Leaves on one caulome are distinctly colored, not only on the margins, but also in the central portion. Anatomical and ecophysiological aspects of the chimeric specimen need to be studied. The abundance and persistence of the chimeric variegation in the individual will be monitored while this phenomenon should be more closely examined for the species.

摘要 斑叶物种凭借其独特的美学价值广受青睐。尽管二者常被混淆，但斑叶现象（variegation）与嵌合现象（chimerism）是两种截然不同的生物学现象。嵌合现象同样可引发植物器官的色彩变异，但其属于一类特殊的遗传嵌合类型。目前针对兰科（Orchidaceae）植物斑叶现象与嵌合现象的研究资料仍较为有限。本研究首次报道了兰科拉利安兰亚族（Laeliinae）的野生叶部嵌合突变体。2020年7月，研究人员于巴西东北部巴伊亚州萨尔瓦多市的保护地——阿巴埃特湖与沙丘环境保护区（Área de Proteção Ambiental das Lagoas e Dunas do Abaeté）内的滨海沙生群落（restinga）片段中，发现并拍摄了一株不育的朱色树兰（Epidendrum cinnabarinum）嵌合个体。该植株的表型呈现为绿色、奶油色与黄色条纹叶以不同比例组合而成的嵌合状态。单茎（caulome）上的叶片不仅叶缘存在显著色彩差异，叶中部同样存在色彩变异。该嵌合标本的解剖学与生态生理学特征亟待进一步研究。研究团队将对该个体中嵌合斑叶的出现丰度与存续稳定性开展监测，同时针对该物种的这一现象展开更为深入的研究。