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- Critical Factors Responsible for Potato Tuberization
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Abstract: The potato (Solanum tuberosum) is the fourth most cultivated and consumed crop worldwide. The swelled stolonic region of the plant is economically important due to its considerable quantities of carbohydrates plus modest quantities of minerals and vitamins. Tuber formation is governed by various external and internal factors including light, oxygen concentration, photosynthate availability, phytochromes, transcription factors, and metabolite availability. This review updates and expands upon our current knowledge regarding the involvement of these variables in the tuberization process. Tuber formation starts at the onset of the supportive season under optimal light conditions where phytochromes in leaves sense the signal. The transmittance of the signal results in photosynthate accumulation, phloem loading with sucrose, phloem transport and unloading at the stolonic region, sucrose entry into the tuber cell, and conversion of sucrose to starch, all under the direction of regulatory enzymes. Several genes are associated with tuberization and regulated either positively or negatively. During the course of these cellular micro-reactions, a very fine stolonic tip will ultimately be transformed into a fully matured potato tuber. Tuber formation can be increased by genetic modifications, that further improve tuber yield and quality.
PubDate: 2023-05-05
- Seed Dispersal in Pines (Pinus)
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Abstract: Pines (n = 121 species) are important elements of forest ecosystems. They are economically and ecologically valuable and are often at the center of efforts to manage forests to reduce the risk of wildland fires. The pattern and process of pine seed dispersal and seedling establishment have important implications for maintaining healthy forests. 75% of pines are dispersed by wind, and 25% are dispersed by scatter-hoarding birds and rodents. Among the wind-dispersed pines, there are about 20 species that attract the attention of seed-caching animals that gather seeds and cache them in soil, so these species are dispersed by a combination of wind and animals. Animal-dispersed pines often occur in semi-arid ecosystems. The seeds cached by animals are a dynamic resource. Animals pilfer each other’s caches, move them to new sites and recache them. Some seed reside in dozens of different cache sites between seed maturation and seed germination. Many pines are adapted to fire. This involves serotinous cones (about 24 species), which are dense, woody, and lignified and remain closed at maturity. Serotiny establishes a canopy seed bank that can persist for several decades. Shortly after fire, these cones open and shed seeds onto the burned landscape. Pines often mast, producing large crops of seeds at intervals of several years. These large cone crops satiate the appetites of specialist seed predators, resulting in increased seedling establishment and also increases the effectiveness of seed dispersal. In the past, pines have responded to climate change by shifting geographic ranges, and some pines appear to be responding to warming climates in a similar way.
PubDate: 2023-03-22
DOI: 10.1007/s12229-023-09288-8
- Leaf Secretory Structures in Asteraceae: A Synthesis of Their Diversity
and Evolution-
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Abstract: This study presents the first comparative analysis of the leaf secretory structures across Asteraceae. In this work, the leaf secretory structures of more than 500 species of 35 of the 40 tribes and 11 of the 13 subfamilies of Asteraceae are described and compared to evaluate their diversity at the tribe level and to identify evolutionary patterns. Leaf secretory structures are present in 28 of the 35 analyzed tribes and correspond to canals (recorded in 17 tribes), secretory cavities (1 tribe), hydathodes (19 tribes), laticifers (4 tribes) and glandular trichomes (24 tribes). Canals are mostly associated with vascular bundles and predominate in Asteroideae, while cavities were only present within Tageteae. Hydathodes occur in leaves without divisions and with well-developed teeth. Laticifers were observed only in the tribes of Cichorioideae. Seven glandular trichome morphotypes were differentiated by their cellular composition and shape. These observations together with the available information showed that secretory structures are found in 80% of the Asteraceae tribes. Four of the 40 tribes did not present any type of secretory structure. Our study reveals that almost all of the tribes possess one to three types of secretory structures, and are absent in some early-diverging clades. Character evolution analyses show that glandular trichomes are plesiomorphic in Asteraceae. This study found that secretory structures prevail in late-diverging lineages and were taxonomically informative at different levels. Our comparative study of the secretory structures in Asteraceae is essential for the standardization of its terminology and will provide a frame of reference for future studies.
PubDate: 2023-03-01
DOI: 10.1007/s12229-022-09276-4
- Phylogenetic, Developmental and Functional Aspects of Stomatal Patterning:
Lessons from Magnoliids-
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Abstract: The magnoliid clade encompasses 18 extant families arranged in four orders, plus several extinct taxa, including some of the most ancient angiosperm fossils. The clade is characterized by paracytic stomata with a distinct pair of lateral subsidiary cells that flank the guard cells, though other stomatal types are also reported, including anomocytic and anisocytic. In contrast with monocots, the paracytic stomata of magnoliids develop from linear triads, and the lateral subsidiary cells are stomatal-lineage ground cells (SLGCs). Anisocytic stomata typically possess three SLGCs. Amplifying divisions are rare in magnoliids, but occur in some Piperales, in association with anisocytic stomata. Differences in mature stomatal types result from differences in cell shape and polarity at critical developmental stages. Stomatal clusters have been reported in Cinnamomum (Lauraceae) and Galbulimima (Himantandraceae), but neither are apparently formed by amplifying divisions, in contrast with eudicots. In Galbulimima, each peltate scale hair is surrounded by a ring of 3–8 non-contiguous stomata, each derived from different initial meristemoids.
PubDate: 2023-01-19
DOI: 10.1007/s12229-023-09287-9
- A Comprehensive Review on the Taxonomy, Ecology, Reproductive Biology,
Economic Importance and Conservation Status of Indian Himalayan
Rhododendrons-
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Abstract: The Indian Himalaya is characterized by high plant diversity and endemism levels. Here, the genus Rhododendron is one of the largest flowering plant genera. The flowering of rhododendrons across elevations in the Himalaya supports insects, birds, and animal movements seasonally. Their diverse life forms and habits also form an important structural component of diverse vegetation types from tropical to temperate forests and alpine thickets. Rhododendrons are also a source of livelihood for many rural communities in the Himalaya. The high ecological and economic significance of rhododendrons in this mountain region qualifies it as an important genus for further investigation and exploration. However, over time, climate change and the ever‐increasing demand for natural resources have collectively exerted considerable pressure on Indian Himalayan rhododendrons in their natural habitats. Available data on various aspects of taxonomy, ecology and conservation status are scanty. There is an urgent need to assess the potential ecological and economic benefits that rhododendrons provide to local mountain communities and associated wildlife. This critical review provides comprehensive detail on taxonomy, evolutionary history, ecology, reproductive biology, hybridization, economic importance, impact of climate change on its ecology and evolution, and the conservation status of rhododendrons in the Indian Himalaya. Further, we conclude with a discussion of the strategies to be adopted for the conservation of Rhododendron-dominated forests in the Indian Himalaya. This comprehensive compilation will open new perspectives for future studies and improve ongoing conservation efforts to manage valuable plant resources.
PubDate: 2022-12-01
DOI: 10.1007/s12229-021-09273-z
- Composition of Sexual Fluids in Cycas revoluta Ovules During Pollination
and Fertilization-
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Abstract: The composition of fluids that mediate fertilization in cycads is described for the first time. Using tandem mass spectrometry, proteomes of two stages of fluid production, megagametophyte fluid and archegonial chamber fluid production, are compared in Cycas revoluta. These were compared with the proteome of another sexual fluid produced by ovules, the pollination drop proteins. Cycad ovules produce complex liquids immediately prior fertilization. Compared with the pollination drops that mainly had few proteins in classes involved in defense and carbohydrate modification, megagametophyte fluid and archegonial chamber fluid had larger proteomes with many more protein classes, e.g. proteins involved in programmed cell death. Using high-performance liquid chromatography, megagametophyte fluid and archegonial chamber fluid were shown to have elevated concentrations of smaller molecular weight molecules including glucose, pectin and glutamic acid. Compared to megagametophyte fluid, archegonial chamber fluid had elevated pH as well as higher osmolality.
PubDate: 2022-12-01
DOI: 10.1007/s12229-021-09271-1
- Leaflet Anatomical Diversity in Zamia (Cycadales: Zamiaceae) Shows Little
Correlation with Phylogeny and Climate-
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Abstract: Cycads (Cycadales) are among the most ancient lineages of extant seed-bearing plants and are the most threatened plant order on Earth, with circa 75% of the 356 accepted species endangered or threatened with extinction. Zamia is the most species-rich (81 spp.) and widely distributed cycad genus in the Americas, notable for its morphological and ecological diversity. Across the genus, there appears to be a high degree of convergence among macromorphological traits, with many characters that are useful for species identification proving uninformative for elucidating relationships among species. However, it remains unknown whether anatomical variation in leaflet structure corresponds with phylogenetic or geographic patterns, as has been investigated in Dioon and Cycas. Here, we present a broad comparative survey of leaflet anatomy across Zamia species with the goals of describing anatomical diversity and uncovering diagnostic characters for resolved clades. Anatomical characters were scored based on the literature and newly prepared sections of leaflets from 20 Zamia species plus the outgroup species Microcycas calocoma. The resulting matrix covers 39 Zamia species representing all five major clades and spanning the geographic distribution of the genus. Anatomical characters scored from leaflet sections were mapped onto a previously published phylogeny and evaluated for their phylogenetic signal. Most anatomical characters examined are not diagnostic for clades, but newly reported mesophyll sclereids may be unique to one large lineage. Given the widespread incongruence between phylogenetic relationships and the distribution of anatomical traits, we tested the relationship between anatomical characters and environmental signals but did not uncover significant correlations between anatomy and ecology. While further work is required to elucidate the evolutionary history of anatomical characters in this genus, this research improves our understanding of micromorphological character evolution, anatomical diversity, and phylogenetic relationships within this highly threatened lineage of plants.
PubDate: 2022-12-01
DOI: 10.1007/s12229-021-09272-0
- An Overview on Orchids and their Interaction with Endophytes
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Abstract: Orchids, being one of nature’s most magnificent as well as abundant plant species, are often a bit of an enigma because their seeds lack endosperm and rely on endophytes for seedlings, development, as well as evolution. Orchids are valued by ecologists as well as the community at large for their decorative, therapeutic, as well as nutritional content. Many orchid species have become affected and extinct as a result of growers’ eagerness to obtain them. The current orchid study has concentrated on isolating and identifying mycorrhizal and non-mycorrhizal endophytes that lead to orchid growth and development and also the synthesis of useful bioactive compounds. In the large-scale biosynthetic pathway of industrially as well as pharmaceutically essential biomolecule derivatives, the biodynamics of orchid-fungal endophytes is assisted for renewable production of bio-applications and technologies. The associations between orchids as well as endophytes are the focus of the study.
PubDate: 2022-12-01
DOI: 10.1007/s12229-022-09275-5
- Retraction Note: Ecological and Biological Features of the Primrose
Distribution in Transbaikalia as the Model Territory of Eastern Siberia-
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PubDate: 2022-09-20
DOI: 10.1007/s12229-022-09286-2
- Richness, Endemism and Floristic Affinities of the Palms of Mexico
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Abstract: The Arecaceae family is ecologically, ethnobotanically and floristically important in Mexico; however, an updated review is required. Here, we investigate the species richness, floristic geographic affinities, and conservation status of the native Mexican palm flora. We constructed a database of the distribution of species by state, performed a cluster analysis, and identified threatened species according to the Mexican red list (NOM-ECOL-059). We found that Mexico hosts 3 subfamilies, 10 tribes, 21 genera, and 99 species of palms (37.7% of which are endemic). Compred to other families, Arecaceae presents intermediate diversity, in which 62.7% of the species are considerd rare. Arecaceae is one of the most threatened families in Mexico. Five large regions are segregated according to species composition (similarity < 8%). Western Mexico exclusively presents Nearctic elements; the tribes Chamaedoreeae, Sabaleae, and Trachycarpeae are the most diversified. The genera Brahea, Sabal and Washingtonia prefer calcareous substrates, and are responsible for the distinctiveness of the Mexican palm flora. The species assemblage has South American and Laurasian origins. The remarkable species richness of Mexican palms is due to the speciation of these Chamaedoreeae, Sabaleae and Trachycarpeae tribes. The greatest species richness is presented in the South-Southeast region of the country (CAM, Q.ROO, YUC, CHIS, OAX, VER, TAB, PUE). Given the importance of palms for humans and the threatened status of the family in general, a more comprehensive analysis of the taxonomy and systematics of the family is required in Mexico, as well as to motivate the continued scientific study of these key plants. Specifically, more studies are required of the ecology, conservation, and sustainable management of the family in the southern states such as Chiapas, Oaxaca and Veracruz, which present the highest species richness, but also face rapid anthropogenic transformation.
PubDate: 2022-09-09
DOI: 10.1007/s12229-022-09284-4
- A Review on the Ecology, Evolution and Conservation of Piper (Piperaceae)
in India: Future Directions and Opportunities-
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Abstract: The genus Piper (Family Piperaceae), consisting of more than 2000 species worldwide, is one of the most speciose genera of flowering plants that belong to the broad category known as basal angiosperms. Piper is known for the several medicinally and economically important species that have been used throughout their native range. Interestingly, this genus is also one of the most taxonomically challenging genera among the angiosperms. The presence of taxonomically complex as well as ecologically and economically important species makes Piper an excellent study system to address the evolution of tropical biodiversity. Being an early-diverging angiosperm genus, understanding Piper systematics and divergence patterns holds vital clues to plant evolution in the tropics. However, research on this plant group is still in a nascent stage, with the primary focus being on its medicinal importance and natural product chemistry. Its distribution, natural history, ecology, evolution and systematics remain less explored. Lack of such knowledge will impede the ongoing conservation effort and may affect the sustainable utilization of this valuable plant resource. The Indian subcontinent is an important center of Piper diversity harboring ca. 100 species, including several economically and medicinally important species such as Black pepper. Piper species in India have a high potential for future utilization; however, their conservation status and needs have not been widely reviewed. Here, we review the taxonomy, ecology and evolution, of Piper species, the threats they face, and further discuss future research directions and suggest ways forward in conserving and effectively utilizing this important plant group in India.
PubDate: 2022-09-01
DOI: 10.1007/s12229-021-09269-9
- Overview of Cold Stress Regulation in Plants
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Abstract: Among different environmental stresses,cold stress can significantly affect plant’s physiological activity, biochemical metabolism, growth,development and crop productivity. Problems due to cold stress should be addressed seriously keeping in concern extreme temperature events due to climate change, alarming increase in population growth and demanding food needs. Cold signal is recognized by receptors of cell membrane,severity of which is determined by factors like light and temperature. The signal is transduced by cold responsive genes, second messengers like calcium and transcription factors to exert symptoms including decreased germination, stunted growth, chlorosis, wilting of leaves, compromised reproductive development and ultimately necrosis. Cold stress induces cell membrane damage, reduction in scavenging enzymes’ activity, loss of energy in photosynthetic apparatus and stability of proteins. This review presents a broader overview of components regulating cold stress responses, changes in physiological processes, transcriptional; post-transcriptional regulations,coldsignaling pathway and interactions with photoreceptors, phytohormones, pathogenesis-related genes, microbial interactions during cold stress.
PubDate: 2022-09-01
DOI: 10.1007/s12229-021-09267-x
- Estimation of genetic diversity and its exploitation in plant breeding
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Abstract: Estimation of genetic diversity is a prerequisite to select genetically diverse parents. Availability and collection of genetically diverse parents contribute significantly towards the selection and utilization of promising parents in plant breeding to develop a commercial variety or hybrid. Germplasm is an important source for various qualitative and quantitative traits that may be used to introgress through combination breeding for the improvement of the existing cultivars or development of new cultivars and hybrids by using marker assisted selection. Genetic diversity refers to the variations among the alleles of a gene and it may be examined at nucleotide level in the DNA sequence. Various classical and DNA tools are available to access genetic diversity at morphological and molecular levels and can be expressed in the form of dendrogram, percentage polymorphic loci and genetic distance. Estimation of genetic diversity using molecular techniques is more reliable as it is based on highly polymorphic molecular markers which remain unaffected by the influence of environment. Genetically diverse genotypes are used as valuable source by the plant breeders for the development of new or improved crop varieties with desirable traits to cope up the biotic and abiotic stresses such as drought tolerant, salt tolerant, insect pest and disease resistance etc. This article reviews various traditional to molecular methods used in estimation of genetic diversity and their exploitations in plant breeding programme.
PubDate: 2022-09-01
DOI: 10.1007/s12229-021-09274-y
- Palynological Diversity of Melliferous flora around Apiaries from District
Mardan Khyber Pakhtunkhwa-Pakistan-
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Abstract: The guiding principles for raising beekeeping products in developing countries provide support for commercializing honey production in order to generate income for beekeepers through the exploration of melliferous flora. The main objective of this study was to conduct a preliminary investigation into the pollen morphology of selected melliferous species that are frequently visited by honeybees in the vicinity of apiaries in the district of Mardan, Khyber Pakhtunkhwa. In this study, an updated overview was provided by reviewing the literature regarding palynological investigation of melliferous flora. The morpho-palynological features, dominant plant families visited by honeybees, and life forms of melliferous species were also discussed. The Acetolysis method was used to prepare the microscopic slides of pollen, measure and describe the qualitative and quantitative features using LM and SEM. Results showed maximum pollen polar and equatorial diameter in M. azadirachta (37.9 μm) and (40.9 μm) respectively. The polar to equatorial diameter ratio (P/E) was observed to be the highest in M. domestica (1.14). Colpi length was calculated to be the highest in the P. granatum (13.8 μm). The highest percentage of pollen fertility was calculated in V. tricolor (92.5%), whereas the lowest was in O. rosea (64.28%). Studied characters under LM and SEM have appeared as a useful tool for the delimitation of melliferous flora, which may lead to the correct identification of the potential and valuable bee floral resources for beekeepers. The outcomes of this study aid in the assessment of melliferous flora and help in providing conservation measures for the sustainable development of beekeeping and the honeybee flora of the region.
PubDate: 2022-09-01
DOI: 10.1007/s12229-021-09268-w
- The Ligule in Poaceae: a Historical and Evolutionary Review
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Abstract: Ligules are classified, predominantly, on their position and morphology, which are still without a consensus as to their nature and diversity in an evolutionary context in Poaceae. Based on a broad review of this structure, we have identified five hypotheses for the definition of ligules, originating between the years 1800 and 1834; some of these hypotheses are still valid today. Our results also demonstrate that 95.28% of the family representatives have homoligulate ventral ligules and 1.75% have heteroligulate ventral ligules, with Panicoideae being the subfamily with the greatest morphological diversity of ligules. Dorsal and culm leaf ligules occur mainly in Puelioideae and Bambusoideae (except in Olyreae), and may occasionally occur in Pooideae, Panicoideae and Chloridoideae. Although homoligulate and ciliate ventral ligules are ancestral states in the Poaceae, several reversals occurred within the subfamilies so that the eciliate membrane type is more common (especially in the BOP clade).
PubDate: 2022-08-24
DOI: 10.1007/s12229-022-09285-3
- Development, Diversity and Dynamics of Plant Architecture in Utricularia
subgenus Polypompholyx – Towards Understanding Evolutionary Processes in
the Lentibulariaceae-
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Abstract: To uncover the nature of various kinds of stolons of Utricularia subgenus Polypompholyx (Lentibulariaceae) we studied branching of stolons by scanning electron microscopy, statistically investigated correlations of stolon types and other traits across 56 species, and evaluated seedling development and process morphological aspects. Some results were compared to the sister genera Pinguicula and Genlisea. A key to nine stolon types in Polypompholyx is provided. Predominant stolon types were rhizoids, runner stolons with rhizoids on nodes, and runner stolons without rhizoids on nodes but with bladders on internodes. Stolon types were taxonomically relevant and correlated to the distribution/climate. They obviously diverged with speciation events in Australia. Examined seedlings of Genlisea and Polypompholyx showed similar developmental patterns. Stolons were homologous to traps and leaves. Selected subterranean organs contained specific but similar process combinations of roots, shoots and/or leaves. We assume the Genlisea-Utricularia ancestor trap included processes of a Pinguicula root and leaf.
PubDate: 2022-08-12
DOI: 10.1007/s12229-022-09283-5
- Vascular epiphytes in Argentinian Yungas: distribution, diversity, and
ecology-
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Abstract: Vascular epiphytes are an important component of the flora of subtropical regions, but they remain understudied compared to tropical regions. Subtropical montane region of Yungas in Argentina has high epiphyte diversity, but information on epiphytes remain in little disseminated sources such as herbariums, theses and publications not available on the web. The objective of this study was to describe the distribution and diversity of epiphytes and to review ecological research on epiphytes in Yungas of northwestern Argentina. Occurrence records of epiphytes were compiled to prepare a floristic list, to describe spatial bias, and latitudinal and altitudinal patterns. There are 168 epiphyte species in Argentinian Yungas, which belong mainly to the families Orchidaceae, Bromeliaceae, and Polypodiaceae. Most species are holoepiphytes and facultative epiphytes (83%), and the rest are trees, herbs, and shrubs that occasionally occur as epiphytes. The species richness of the 14 most abundant epiphyte species in this region peaks at 1500 m, and decreases at higher and lower elevations. Most trees with a diameter at breast height ≥ 10 cm (62.2%) are epiphyte hosts, and epiphytes are most diverse in larger than in smaller native trees of this region. Species richness and cover of epiphytes increased with the diameter at breast height of Ocotea porphyria, the most important host tree for epiphytes in this region. It is expected that this study will serve to acknowledge the high diversity of epiphytes in the region and identify gaps in knowledge for new sampling and studies.
PubDate: 2022-06-07
DOI: 10.1007/s12229-022-09281-7
- Apomixis: A Foresight from Genetic Mechanisms to Molecular Perspectives
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Abstract: Apomixis is considered to be a natural mode of clonal propogation from seed to seed, in which progeny serves as a replica of maternal genotype. The process evades creation of variation by circumventing sexual fusion and recombination, offering great advantage to fix heterosis or hybrid vigour in plants. As this would permit the conservation of complex favourable genotypes that are of agricultural value, it has immense potential in crop seed production. In order to accomplish this, a comprehensive knowledge on the genetic basis and the molecular mechanisms regulating different components of apomixis stands as a key prerequisite. So far, despite of the persistent interest and extensive research on apomixis, the underlying gene regulatory networks and their evolutionary origins are not well deciphered and still remain unclear. From the developmental perspective, apomixis is widely accepted to be controlled or deviated form of sexual reproduction and studies based on comparative analysis of genes or mutants regulating sexual and apomictic pathways revealed their resemblance across various plant species. Since apomixis is a complex, yet well regulated phenomenon that constantly requires action of specific genes during all developmental stages, the present review summarises recent advances in apomixis and compiles information on vital genes and mutants involved in regulating apomixis during various stages of development. Graphical abstract Graphical abstract: Brief illustration on mechanisms of apomictic and sexual life cycle in angiosperms. Apomixis avoids the process of meiosis and recombination offering advantage over sexuals by conservation of heterosis or vigor for several generations, easy maintenance of superior genotypes and rapid production of homozygous lines. In sexuals owing to nuclear division and fertilization, fixation of heterosis cannot be achieved and maintenance/development of homozygous lines becomes intricate.*Based on the fertilization the ploidy of endosperm may vary. 
PubDate: 2022-06-01
DOI: 10.1007/s12229-021-09266-y
- Pollen morphology and its implication in the taxonomy of some selected
tribes of the Asteraceae of Hainan Island South China-
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Abstract: Pollen morphological traits are mostly used in resolving taxonomic problems at various taxonomic ranks to define species boundaries for long in the systematics and evolution. This study aims to provide new and useful information regarding the extent of pollen morphological diversity among the Asteraceae taxa and thus to contribute a better understanding of the taxonomy of studied species. These species belonged to three subfamilies Asteroideae having eight tribes (Senecioneae, Heliantheae, Milleriae, Eupatorieae, Coreopsideae, Inulaceae, Plucheeae, Tageteae, followed by Cichorioideae (Cichorieae) and the Vernonioideae (Vernonieae). Both light and scanning electron microscopy were used to investigate the ultrastructure of the exine. Principal component analysis (PCA) was performed to show the relationship among the Asteraceae taxa. The results showed two main types the echinolophate and echinate pollen. The echinate and echinolophate features were found to have a significant taxonomic value at the family level that delimits the Asteraceae from rest of the families. Besides, the ehinolophate feature was found to be the diagnostic trait of the tribe Vernonieae (Elephantopus tomentosus), Cichorieae (Youngia japonica) and echinate mixed with other morphological features in the inter-spinal area i.e. perforate, verrucate, scabrate, micro-reticulate and psilate were found in rest of the tribes. Aperture traits were found useful to differentiate between tribes. The maximum spines length was found in Bidens pilosa (5.43 μm) while maximum pollen size was observed in Elephantopus tomentosus (28.43 × 21.93 μm) followed by Tagetes erecta (28.36 × 19.51 μm). Furthermore, the size, spines length, density, arrangement and number of the spines at the apocolpium region were found useful taxonomically important to discriminate the species. The overlapped features showed interspecies relationships because to be in the same families while the interspecies variation in pollen traits validate their existence as distinct species. The PCA analysis showed that the spine length, polar axis, equatorial diameter, colpus length and width, P/E ratio and inter-spinal area were found useful pollen morphological traits. In conclusion, our results showed that pollen morphology has a significant taxonomic potential to identify and define species boundaries at the tribe and generic levels. Hence, the pollen features can be used as an additional tool for regrouping taxa within the family Asteraceae by using both light and scanning electron microscopic techniques.
PubDate: 2022-05-20
DOI: 10.1007/s12229-022-09277-3
- Phytogeographic Meta-Analysis of the Vascular Epiphytes in the Neotropical
Region-
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Abstract: The Neotropical Region (NR) is one of the areas with the most plant diversity globally, and its richness of vascular epiphyte (VE) species is higher than Africa and Asia combined. This richness is a consequence of the heterogeneous climate and geological history of the region, both factors also being responsible for the plant distribution patterns. Here, we aimed to explore the phytogeographic relationships of the VE in the NR using 14,636 identified records from 173 surveys exclusively of VE, carried out in 14 countries and 23 biogeographic provinces, comprising 3849 identified species. We assessed the floristic patterns and relationships with climatic variables by multivariate analysis (cluster and ordination analyses). The clustering formed 13 main groups, partly corresponding to the biogeographic units of the NR. Our results demonstrate consistent floristic patterns confirmed through the analysis of floristic similarity, corroborating previous biogeographic classifications in well-studied areas, while broader patterns were found in poorly studied areas. We found a floristic gradient pattern, which allowed us to understand the relationships between environmental conditions and floristic patterns. Furthermore, we discuss our results under the light of the history that likely shaped the current distribution patterns and richness of the VE in the NR. The VE proved to be an important model for testing biogeographic classifications. We encourage the studies of this synusia in the several geographical gaps that remain in the NR, which undoubtedly will improve further studies and support conservationist policies.
PubDate: 2022-01-20
DOI: 10.1007/s12229-021-09270-2
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