Department of Forest Botany, Poznan University of Life Sciences, Poznań, Poland.
Department of Plant Taxonomy, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.
PLoS One. 2018 Oct 24;13(10):e0204557. doi: 10.1371/journal.pone.0204557. eCollection 2018.
The Erica genus has as yet not been investigated satisfactorily in terms of palynology. Its complicated taxonomic system, large number of species, as well as its extensive but disrupted range of occurrence, all contribute to the fact that few researchers have undertaken investigations of this species. It was assumed that the research results would be representative thanks to a complex comparative analysis of all diagnostical, morphological pollen features performed on properly selected plant material, representing the most important distinguished intrageneric taxons at the present time (45 species from all five subgenera and 22 sections), both discriminated pollen dispersal units (tetrads and monads) as well as the main centres of genus occurrence and diversification (species from Europe, the Republic of South Africa (RSA) and Madagascar). The study revealed that the diagnostic features of the pollen grains studied were: pollen dispersal unit, exine ornamentation, P/E ratio, tetrad diameter (D) and length of polar axis (P). On the basis of these traits, 14 Erica species (six creating monads and eight-tetrads) were distinguished which, in the case of pollen features, constitutes a significant number. Other heaths created small groups, usually containing two or three species, but up to seven species. The present study, based on the highest number of Erica species (45) analysed so far, corroborated the view that an examination of palynological features may assist in clarifying classification systems for the large and taxonomically very difficult Erica genus, in particular, at the level of the subgenus and section, but also at species level. The results obtained indicate the need to continue palynological investigations on the Erica genus.
埃里卡属的孢粉学研究至今仍不令人满意。其复杂的分类系统、大量的物种，以及广泛但分散的分布范围，都导致很少有研究人员对该物种进行研究。由于对所有诊断性、形态花粉特征进行了复杂的比较分析，并在适当选择的植物材料上进行了分析，这些材料代表了目前最重要的区分属内分类群（来自所有五个亚属和 22 个组的 45 种），因此研究结果被认为是具有代表性的，包括区分花粉传播单位（四联体和单体）以及属发生和多样化的主要中心（来自欧洲、南非共和国和马达加斯加的物种）。研究表明，所研究花粉粒的诊断特征为：花粉传播单位、外壁纹饰、P/E 比、四联体直径（D）和极轴长度（P）。基于这些特征，区分了 14 种埃里卡物种（6 种形成单体，8 种形成四联体），就花粉特征而言，这是一个相当大的数量。其他石南科形成小群体，通常包含两个或三个物种，但最多可达七个物种。本研究基于迄今为止分析的最多数量的埃里卡物种（45 种），证实了这样一种观点，即对孢粉学特征的研究可能有助于澄清大型且分类非常困难的埃里卡属的分类系统，特别是在亚属和组的水平上，但也在种的水平上。研究结果表明，需要继续对埃里卡属进行孢粉学研究。
