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：斑叶物种以其独特的观赏美学特征广受青睐。尽管二者常被混淆，但斑叶现象（variegation）与嵌合现象（chimerism）实为两种截然不同的生物学过程。嵌合现象同样可导致植物器官产生色彩变异，但其本质为一类特殊的遗传嵌合体。目前学界关于兰科（Orchidaceae）植物斑叶与嵌合现象的研究资料仍较为匮乏。本研究首次报道了拉利亚亚族（subtribe Laeliinae）野生叶部嵌合突变体的发现记录。2020年7月，研究人员在巴西东北部巴伊亚州萨尔瓦多市的阿巴埃特湖与沙丘环境保护区（Área de Proteção Ambiental das Lagoas e Dunas do Abaeté）内的一处海滨砂生植被片段中，发现并拍摄了一株不育的朱砂树兰（Epidendrum cinnabarinum）嵌合个体。该植株的表型为叶片呈现不同比例的绿色、奶油色与黄色条纹镶嵌分布；单个茎上的叶片不仅叶缘存在色彩变异，中央区域亦存在明显的色泽差异。目前该嵌合标本的解剖学与生态生理学特征尚待研究，后续将对该个体的嵌合斑叶性状的丰度与持续性进行监测，并针对该物种的此类现象展开更为深入的探究。