In this work, we analyse morpho-physiological modifications presented during the allomorphic growth of the aroid vine Rhodospatha oblongata Poepp throughout its ascent into the forest canopy. We test the hypothesis that morphological modifications in the root, shoot and leaf are followed by a gradual improvement of the xylem vascular system in order to increase water acquisition and transport as body size increases. The characterisation of these structural modifications was based on 30-35 specimens divided into six size classes. The dimensions of shoots, leaves and roots were quantified and qualified. The transition from the terrestrial to the epiphytic phase was followed by a simultaneous increase of leaf number and lamina area, together with increased length and diameter of the petiole. Furthermore, as the plant grows, the shoot internodes become shorter and thicker. However, occurrence of aerial roots is the most important characteristic in the ascending phase. In taller individuals, the increase in number of roots with wider xylem vessels guarantees an increased theoretical xylem hydraulic conductance for this growth phase. Along an acropetal direction of the same shoot, the diameter of xylem vessels increased, while the number of vessels per stele area decreased, in contrast with such allometric models as that of West, Brown and Enquist, showing that xylem vessel number and diameter taper in a reverse manner along the same direction. Such structural changes of R. oblongata allow improved foraging for light and water, facilitating the survival of bigger-sized plants of this vine in the canopy.
In herbaceous communities which host many perennial species, belowground clonal organs and traits remain largely overlooked in ecosystem functioning studies. However, the belowground compartment is expected to play a key role as the greatest proportion of biomass is allocated belowground. Our main goal was to test whether including underexplored clonal traits (in tandem with widely used aboveground traits) improves the ability to predict biomass production and soil carbon in temperate grasslands. We examined the relationships between five plant functional traits (canopy height, specific leaf area [SLA], lateral spread, multiplication rate, persistence of rhizome) and biomass allocation (aboveground, roots, rhizomes) and soil organic carbon (SOC). We studied 52 grassland plots clustered in two Central European regions differing by management intensity. We assessed biomass allocated aboveground and belowground (into roots and rhizomes separately). SOC was measured from averaging five soil cores at each plot. Trait community means were calculated for each trait from species compositions using databases. The most important traits in predicting biomass allocation were canopy height and persistence of rhizome. Results, however, differed for the two regions implying context dependency of the relationships. Persistence of rhizome and canopy height emerged as traits largely affecting ecosystem functioning at the less intensively managed grasslands—likely because of their links to biomass production and plant economics spectrum. At the more intensively managed grasslands, canopy height and SLA were negatively correlated with root biomass, with persistence of rhizome playing a (lesser) role. We found no significant predictors for SOC. Synthesis. This study is the first attempt to integrate belowground clonal and aboveground traits to predict biomass allocation and soil carbon. Findings indicate that the ability of plant functional traits in predicting ecosystem functioning is highly context dependent, varying greatly even within the same community type. Only SLA and, to a lesser extent, persistence of rhizome consistently predicted root biomass in the two regions. We call for a broader implementation of the whole‐plant multifunctional approach applied here, ideally extending to other open ecosystems. A free Plain Language Summary can be found within the Supporting Information of this article.
Background and Aims Root sprouting (RS), i.e. the ability to form adventitious buds on roots, is an important form of clonal growth in a number of species, and serves both as a survival strategy and a means of spatial expansion, particularly in plants growing in severely and recurrently disturbed habitats. Occurrence and/or success of plants in severely and recurrently disturbed habitats are determined by two components, viz.; the ability to produce adventitious buds on roots and the vigour of their production. As mechanisms behind different magnitudes of RS remain unclear, our study investigates: (i) whether the presence or absence of specific tissues in roots can promote or limit RS, and (ii) whether there is some relationship between RS ability, RS vigour and species niche. Methods We studied RS ability together with RS vigour in 182 Central European herbaceous species under controlled experimental conditions. We used phylogenetic logistic regressions to model the presence of RS, RS vigour, the relationship between RS and anatomical traits, and the relationship between RS and parameters of species niche. Key Results One quarter of herbs examined were able to produce adventitious buds on roots. They were characterized by their preference for open dry habitats, the presence of secondary root thickening and the occurrence of sclerified cortical cells in roots. Root sprouting vigour was not associated with any specific anatomical pattern but was correlated with the environmental niches of different species, indicating that preferred disturbed and dry habitats might represent a selection pressure for more vigorous root sprouters than undisturbed and wet habitats. Conclusions Our study shows that sprouting from roots is quite common in temperate dicotyledonous herbs. Two components of RS, ability and vigour, should be considered separately in future studies. We would also like to focus more attention on RS in herbs from other regions as well as on external forces and internal mechanisms regulating evolution and the functions of RS in both disturbed and undisturbed habitats.
-(Comparative anatomy of leaf and spathe of Anthurium (Araceae) species from the Atlantic Rain Forest). Leaf and spathe anatomy of nine species of the genus Anthurium (sections Urospadix and Leptanthurium) were analyzed. Plant material was collected from different locations in Brazil and cultivated under identical conditions in the Instituto de Pesquisas Jardim Botânico do Rio de Janeiro. Our objective was to evaluate the diagnostic potential of leaf and spathe anatomy for taxonomic purposes. Leaves presented smooth and striated cuticle, epidermal cells randomly disposed, raised and non-raised stomata, epidermal glands, periclinal divisions of epidermal cells, raphides, druses, carotene and diosmin crystals, palisade parenchyma on the adaxial surface of the midrib and sclerenchymatic fibre sheath in the bundle. The spathes also presented smooth and striated cuticle, epidermal cells in parallel rows, raised and non-raised stomata, epidermal glands, raphides, druses and flavonoidic crystals, uniform mesophyll, and presence of sclerenchyma as fibre caps associated to the vascular bundles. The Anthurium species have differences between leaves and spathes based on anatomical characters, but clustering analysis did not separate the species from different sections. Results indicate that spathe can give a better resolution than leaves for segregation of species groups in Anthurium.Key words -Leptanthurium, taxonomy, Urospadix RESUMO -(Anatomia comparada da folha e espata de espécies de Anthurium (Araceae) ocorrentes na Mata Atlântica). São apresentados dados relativos à anatomia da lâmina foliar e espata de nove espécies do gênero Anthurium (seções Urospadix e Leptanthurium). Os indivíduos foram coletados em diversas partes do Brasil e aclimatados no Instituto de Pesquisas Jardim Botânico do Rio de Janeiro. O objetivo deste estudo foi comparar as características anatômicas da lâmina foliar e da espata, detectando caracteres que sejam potenciais para subsidiar e contribuir aos estudos taxonômicos do gênero Anthurium. Observa-se nas folhas a presença tanto de cutícula lisa quanto estriada, células epidérmicas dispostas ao acaso, estômatos no mesmo nível das demais células da epiderme ou elevados, glândulas epidérmicas e divisões periclinais em células epidérmicas, além de ráfides, drusas, cristais de caroteno e diosmina, parênquima paliçádico na face adaxial da nervura central e bainha de fibras esclerenquimáticas nos feixes. Quanto à espata observa-se cutícula lisa e estriada, células epidérmicas ordenadas de forma paralela, estômatos no mesmo nível das demais células da epiderme ou elevados, glândulas epidérmicas, ráfides, drusas e cristais de natureza flavonoídica; o mesofilo é uniforme, apresentando apenas calotas de fibras associadas aos feixes vasculares, quando não ausentes. As espécies de Anthurium avaliadas mostraram-se distintas quanto à anatomia de folha e espata, mas as análises de agrupamento não permitiram separar espécies de acordo com a respectiva seção. Os resultados indicam ser a espata a estrut...
Background and Aims The aroid vine Rhodospatha oblongata is characterized by a habitat change from terrestrial to canopy, relying on aerial roots at maturity to obtain water and nutrients from the forest soil. We hypothesize that morpho-physiological acclimation occurs in roots as they grow under atmospheric conditions. These changes would guarantee the whole plant survival of aroid vines in the new and potentially stressful habitat of the canopy. Methods Terrestrial and aerial roots were compared on a morpho-physiological basis. Root anatomy, water balance, water absorption capacity via fluorescent tracer, and photochemical activity via chlorophyll fluorescence were measured. Key Results While thin fasciculate roots occur on terrestrial crawling individuals, two clearly distinct aerial roots (anchor and feeder) are produced on canopy individuals, which are both adhered to the host trunk. The color of both aerial roots change during development from red and brownish to striped and green at maturity. Color changes are induced by the replacement of epidermis, exodermis, and outer cortex by an inner layer of lignified cork on the root region exposed to the atmosphere. In the root region that is in contact with the host, covering substitutions do not occur and both exodermis and lignified cork, along with several epidermal hairs, appear. Water retention capacity was higher in green roots than in other root types. Rehydration capacity via water absorption by hairs of aerial roots was confirmed by fluorescence. Chlorophyll fluorescence data indicated low levels of photosynthetic capacity in both root types. Conclusions Plants should evolve strategies to survive stress situations. The transition from soil to canopy imposes abiotic changes and potentially stressful situations to R. oblongata. We conclude that the morpho-physiological changes observed represent an important strategy that permits the maintenance of aroid roots and the survival of R. oblongata in the canopy.
Features of leaf morphology such as secretory duct distribution and venation patterns are important taxonomical tools; however, some species can have variation in these traits. This study evaluates whether the secretory duct distribution in the midrib and venation is similar across different leaves of 17 Aldama species. Six fully expanded leaves (three each of the largest and smallest size) from five distinct plants were selected to analyze the duct distribution. The samples were histologically examined, and the quantitative data were statistically analyzed. The venation pattern was analyzed in five fully expanded leaves of different plants. In all, 23 secretory duct distribution patterns were identified; they showed intra- and inter-species variations except in Aldama anchusifolia (DC.) E.E.Schill. & Panero and A. trichophylla (Dusén) Magenta. The largest number of ducts was not correlated with leaf and midrib dimensions (width and length). Further, Aldama venation could be divided into two groups: (1) pinnate camptodromous brochidodromous type (four species), and (2) acrodromous venation type and its basal and suprabasal variations (13 species). Thus, distinct secretory duct arrangements of the midrib might assist in the discrimination of Aldama species. The venation patterns were also important for distinguishing the majority of species selected.
Vegetative aerial organs are considerably more exposed to environmental conditions and can reflect the specific adaptations of plants to their local environment. Aldama grandiflora species are known to be widely distributed in Brazil; therefore, individuals from different populations of this species are thought to be exposed to different abiotic and biotic conditions. Several anatomical studies conducted on Brazilian Aldama species have mainly focused on the qualitative anatomical characters or traits of these species, but not on their quantitative traits. In this study, we evaluated whether climate and soil conditions can change the morphometry among individuals of A. grandiflora collected from six sites in the Goiás State, Brazil, by assessing their anatomical characters. Further, soil sampling was performed, and climate data were collected from all the six sites. The analysis indicated few statistical differences among the populations evaluated, showing that A. grandiflora presented consistent leaf and stem anatomical characteristics. The small morpho-anatomical differences found among individuals of the different populations evaluated, reflected the soil conditions in which these populations were grown. Therefore, environmental factors have a significant influence on the morpho-anatomy of Aldama grandiflora.Keywords: cerrado, Compositae, morphometry, phenotypic plasticity, leaf anatomy. Condições climáticas e de solo podem alterar a morfo-anatomia entre indivíduos de diferentes localidades? Um estudo de caso emAldama grandiflora (Asteraceae) ResumoOs órgãos vegetativos aéreos estão consideravelmente mais expostos às condições ambientais e podem refletir as adaptações específicas das plantas ao seu habitat. A espécie Aldama grandiflora é amplamente distribuída no Brasil e, dessa forma, indivíduos de diferentes populações podem estar expostos a diferentes condições ambientais. Vários estudos anatômicos realizados com espécies brasileiras do gênero Aldama têm abordado, principalmente, as características anatômicas qualitativas dessas espécies, mas não em suas características quantitativas. Neste estudo avaliamos se as condições climáticas e do solo podem alterar a morfometria entre os indivíduos de A. grandiflora coletados em seis populações do Estado de Goiás. Foram avaliados os caracteres anatômicos foliares e caulinares, além da amostragem do solo e coleta de dados climáticos, para os seis locais. A análise indicou algumas diferenças estatísticas entre as populações avaliadas, mostrando que A. grandiflora apresentou características anatômicas foliares e caulinares bastante consistentes.As pequenas diferenças morfo-anatômicas encontradas entre indivíduos das diferentes populações avaliadas, refletiram as condições do solo nos quais essas populações se desenvolveram. Assim sendo, fatores ambientais relacionados ao clima e condições do solo têm uma influência significativa sobre a morfo-anatomia de Aldama grandiflora.
Background and Aims Petioles are important plant organs connecting stems with leaf blades and affecting light-harvesting ability of the leaf as well as transport of water, nutrients and biochemical signals. Despite the high diversity in petiole size, shape and anatomy, little information is available about their structural adaptations across evolutionary lineages and environmental conditions. To fill our knowledge gap, we investigated the variation of petiole morphology and anatomy of mainly European woody species to better understand drivers of internal and external constraints in an evolutionary context. Methods We studied how petiole anatomical features differed according to whole-plant size, leaf traits, thermal and hydrological conditions, and taxonomical origin in 95 shrubs and trees using phylogenetic distance-based generalized least squares models. Key Results Two major axes of variation were related to leaf area and plant size. Larger and softer leaves are found in taller trees of more productive habitats. Their petioles are longer, with a circular outline and anatomically characterized by the predominance of sclerenchyma, larger vessels, interfascicular areas with fibers and indistinct phloem rays. In contrast, smaller and tougher leaves are found in shorter trees and shrubs of colder or drier habitats. Their petioles have terete outline, phloem composed of small cells and radially arranged vessels, fiberless xylem and lamellar collenchyma. Individual anatomical traits were linked to different internal and external drivers. The petiole length and vessel diameter increase with enlarging leaf blade area. Collenchyma becomes absent with increasing temperature, and petiole outline becomes polygonal with increasing precipitation. Conclusions We conclude that species temperature and precipitation optima, plant height, leaf area and thickness exerted a significant control on petiole anatomical and morphological structures not confounded by phylogenetic inertia. Species with different evolutionary histories but similar thermal and hydrological requirements have converged to similar petiole anatomical structures.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.