Orbicules in south American Balanophoraceae: Analysis of its possible role and its taxonomic value in the family

IF 1.7 4区生物学 Q3 ECOLOGY

Flora Pub Date : 2024-11-12 DOI:10.1016/j.flora.2024.152642

Virginia Cristina Gómez Villafañe , Héctor Arnaldo Sato , Diego Demarco , Ana María Gonzalez

{"title":"Orbicules in south American Balanophoraceae: Analysis of its possible role and its taxonomic value in the family","authors":"Virginia Cristina Gómez Villafañe , Héctor Arnaldo Sato , Diego Demarco , Ana María Gonzalez","doi":"10.1016/j.flora.2024.152642","DOIUrl":null,"url":null,"abstract":"<div><div>Balanophoraceae are root parasites, lacking both chlorophyll and typical cormophytic organization. There have been few studies of pollen dispersal mechanisms in Balanophoraceae, and no studies on structures accompanying pollen, such as orbicules. Anthers were analyzed in five South American taxa of Balanophoraceae (Langsdorffia hypogaea, Lophophytum pyramidale, L. mirabile. subsp. bolivianum, Ombrophytum subterraneum and Helosis cayennensis), in order to: (1) determine the presence of orbicules, characterize them and relate their presence with the tapetum type, characteristics of the anther wall and dehiscence, and the pollination mode; (2) and analyze its possible taxonomic value in relation to the phylogeny of the family Balanophoraceae. In three genera (Lophophytum, Langsdorffia and Ombrophytum), the anthers were found to be dithecous, tetrasporangiate with longitudinal dehiscence. In these taxa the endothecium is present and is responsible for dehiscing the anthers. In Helosis the pollen sacs are welded in a synandrium with apical groves and lacking an endothecium. In all species, a secretory tapetum is responsible for nourishing the pollen grains during their formation. The presence of orbicules is variable among the species studied: it is found in Lophophytum and Langsdorffia, and is absent in Ombrophytum and Helosis. In Lophophytum the orbicules appear as small and spheroidal corpuscles with smooth surfaces. In Langsdorffia hypogaea the orbicules are conspicuous spherical, ellipsoid to ovoid forms. This study shows that there is no relationship between layers present in mature anthers, dehiscence type, pollination mode and orbicules presence. We report for the first time the presence of orbicules in the holoparasitic family Balanophoraceae belonging to the order Santalales, in which there is scarce information available regarding the presence of orbicules. Given the intergeneric variations and the consistency at generic level observed in the taxa here analyzed, orbicules may have predictive value and potential for systematically oriented research questions.</div></div>","PeriodicalId":55156,"journal":{"name":"Flora","volume":"321 ","pages":"Article 152642"},"PeriodicalIF":1.7000,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Flora","FirstCategoryId":"99","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0367253024001944","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ECOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Balanophoraceae are root parasites, lacking both chlorophyll and typical cormophytic organization. There have been few studies of pollen dispersal mechanisms in Balanophoraceae, and no studies on structures accompanying pollen, such as orbicules. Anthers were analyzed in five South American taxa of Balanophoraceae (Langsdorffia hypogaea, Lophophytum pyramidale, L. mirabile. subsp. bolivianum, Ombrophytum subterraneum and Helosis cayennensis), in order to: (1) determine the presence of orbicules, characterize them and relate their presence with the tapetum type, characteristics of the anther wall and dehiscence, and the pollination mode; (2) and analyze its possible taxonomic value in relation to the phylogeny of the family Balanophoraceae. In three genera (Lophophytum, Langsdorffia and Ombrophytum), the anthers were found to be dithecous, tetrasporangiate with longitudinal dehiscence. In these taxa the endothecium is present and is responsible for dehiscing the anthers. In Helosis the pollen sacs are welded in a synandrium with apical groves and lacking an endothecium. In all species, a secretory tapetum is responsible for nourishing the pollen grains during their formation. The presence of orbicules is variable among the species studied: it is found in Lophophytum and Langsdorffia, and is absent in Ombrophytum and Helosis. In Lophophytum the orbicules appear as small and spheroidal corpuscles with smooth surfaces. In Langsdorffia hypogaea the orbicules are conspicuous spherical, ellipsoid to ovoid forms. This study shows that there is no relationship between layers present in mature anthers, dehiscence type, pollination mode and orbicules presence. We report for the first time the presence of orbicules in the holoparasitic family Balanophoraceae belonging to the order Santalales, in which there is scarce information available regarding the presence of orbicules. Given the intergeneric variations and the consistency at generic level observed in the taxa here analyzed, orbicules may have predictive value and potential for systematically oriented research questions.

查看原文本刊更多论文

南美洲芭蕉科植物的鳞茎：分析其可能的作用及其在该科中的分类价值

芭蕉科植物是根寄生植物，缺乏叶绿素和典型的球根植物组织。有关芭蕉科植物花粉传播机制的研究很少，对花粉附着结构（如花粉囊）的研究也不多。本研究分析了五种南美洲巴兰角科分类群（Langsdorffia hypogaea、Lophophytum pyramidale、L. mirabile. subsp：(1)确定是否存在眼珠，描述眼珠的特征，并将眼珠的存在与锥体类型、花药壁和开裂特征以及授粉方式联系起来；(2)分析眼珠在 Balanophoraceae 科系统发育中可能具有的分类价值。在三个属（Lophophytum、Langsdorffia 和 Ombrophytum）中，发现花药为二室、四孢子囊状，具有纵向开裂。在这些分类群中，内皮层存在并负责花药开裂。在 Helosis 中，花粉囊被焊接在带有顶端凹槽的合胞体中，缺乏内皮层。在所有物种中，花粉粒在形成过程中都由分泌性的绦膜来滋养。在所研究的物种中，轨道的存在是可变的：在 Lophophytum 和 Langsdorffia 中发现了轨道，而在 Ombrophytum 和 Helosis 中则没有。在 Lophophytum 中，球体呈小球状，表面光滑。在 Langsdorffia hypogaea 中，球体呈明显的球形、椭圆形或卵圆形。这项研究表明，成熟花药中存在的花药层、开裂类型、授粉方式与花球的存在之间没有关系。我们首次报道了属于山茶目 Balanophoraceae 的全缘花科中存在的小花球，在该科中有关小花球存在的信息很少。鉴于在本文分析的类群中观察到的属间变异和属级上的一致性，轨道可能具有预测价值和系统性研究问题的潜力。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Flora 生物-植物科学

CiteScore

3.30

自引率

10.50%

发文量

130

审稿时长

54 days

期刊介绍： FLORA publishes original contributions and review articles on plant structure (morphology and anatomy), plant distribution (incl. phylogeography) and plant functional ecology (ecophysiology, population ecology and population genetics, organismic interactions, community ecology, ecosystem ecology). Manuscripts (both original and review articles) on a single topic can be compiled in Special Issues, for which suggestions are welcome. FLORA, the scientific botanical journal with the longest uninterrupted publication sequence (since 1818), considers manuscripts in the above areas which appeal a broad scientific and international readership. Manuscripts focused on floristics and vegetation science will only be considered if they exceed the pure descriptive approach and have relevance for interpreting plant morphology, distribution or ecology. Manuscripts whose content is restricted to purely systematic and nomenclature matters, to geobotanical aspects of only local interest, to pure applications in agri-, horti- or silviculture and pharmacology, and experimental studies dealing exclusively with investigations at the cellular and subcellular level will not be accepted. Manuscripts dealing with comparative and evolutionary aspects of morphology, anatomy and development are welcome.