Variation In Leaf Shape Research Articles

Divergent leaf shapes among Passiflora species arise from a shared juvenile morphology.

Not only does leaf shape vary between Passiflora species, but between sequential nodes of the vine. The profound changes in leaf shape within Passiflora vines reflect the temporal development of the shoot apical meristem from which leaves are derived and patterned, a phenomenon known as heteroblasty. We perform a morphometric analysis of more than 3,300 leaves from 40 different Passiflora species using two different methods: homologous landmarks and Elliptical Fourier Descriptors (EFDs). Changes in leaf shape across the vine are first quantified in allometric terms; that is, changes in the relative area of leaf subregions expressed in terms of overall leaf area. Shape is constrained to strict linear relationships as a function of size that vary between species. Statistical analysis of leaf shape, using landmarks and EFDs, reveals that species effects (regardless of node) are the strongest, followed by interaction effects between species and heteroblasty (i.e., species‐specific patterns in leaf shape across nodes) and that heteroblasty effects across nodes (regardless of species) are negligible. The ability of different nodes to predictively discriminate species and the variability of landmark and EFD traits at each node is then analyzed. Heteroblastic trajectories, the changes in leaf shape between the first and last measured leaves in a vine, are then compared between species in a multivariate space. Leaf shape diversity among Passiflora species is expressed in a heteroblastic‐dependent manner, unique to each species. Leaf shape is constrained by linear, allometric relationships related to leaf size that vary between species. There is a strong species × heteroblasty interaction effect for leaf shape, suggesting that different leaf shapes between species arise through changes in shape across nodes specific to each species. The first leaves in the series are not only more like each other, but are also less variable across species. From this similar, shared leaf shape, subsequent leaves in the heteroblastic series follow divergent morphological trajectories. The disparate leaf shapes characteristic of Passiflora species arise from a shared, juvenile morphology.

Rare sporophyte found in Europe for Herbertus sendtneri with a range expansion to Africa and Malesia

The sporophytes of the genus Herbertus are rare or completely absent in some areas. The first discovery of the sporophyte of Herbertus in Europe, on H. sendtneri from a herbarium specimen collected in Austria in 1851, is reported here. We report that finely papillose spores characterize Herbertus species which have originated in the Northern Hemisphere, whereas the spores of the species which have originated in the Southern Hemisphere are tuberculate or shortly spinulose. Based on morphological studies of over 600 herbarium specimens of Herbertus, supported by previously published molecular phylogenetic studies, H. armitanus and H. circinatus are new synonyms of H. sendtneri. It is distinct from other Northern Hemisphere species by its coarsely toothed leaf base, despite large variation in leaf size and shape, and leaf apex cilia. The range of H. sendtneri is now extended to east Africa (Tanzania) and Malesia (Papua New Guinea and the Solomon Islands).

Erratum to: Morphometric analysis of Passiflora leaves: the relationship between landmarks of the vasculature and elliptical Fourier descriptors of the blade.

BackgroundLeaf shape among Passiflora species is spectacularly diverse. Underlying this diversity in leaf shape are profound changes in the patterning of the primary vasculature and laminar outgrowth. Each of these aspects of leaf morphology—vasculature and blade—provides different insights into leaf patterning.ResultsHere, we morphometrically analyze >3300 leaves from 40 different Passiflora species collected sequentially across the vine. Each leaf is measured in two different ways: using 1) 15 homologous Procrustes-adjusted landmarks of the vasculature, sinuses, and lobes; and 2) Elliptical Fourier Descriptors (EFDs), which quantify the outline of the leaf. The ability of landmarks, EFDs, and both datasets together are compared to determine their relative ability to predict species and node position within the vine. Pairwise correlation of x and y landmark coordinates and EFD harmonic coefficients reveals close associations between traits and insights into the relationship between vasculature and blade patterning.ConclusionsLandmarks, more reflective of the vasculature, and EFDs, more reflective of the blade contour, describe both similar and distinct features of leaf morphology. Landmarks and EFDs vary in ability to predict species identity and node position in the vine and exhibit a correlational structure (both within landmark or EFD traits and between the two data types) revealing constraints between vascular and blade patterning underlying natural variation in leaf morphology among Passiflora species.

The arms race between heliconiine butterflies and Passiflora plants - new insights on an ancient subject.

Heliconiines are called passion vine butterflies because they feed exclusively on Passiflora plants during the larval stage. Many features of Passiflora and heliconiines indicate that they have radiated and speciated in association with each other, and therefore this model system was one of the first examples used to exemplify coevolution theory. Three major adaptations of Passiflora plants supported arguments in favour of their coevolution with heliconiines: unusual variation of leaf shape within the genus; the occurrence of yellow structures mimicking heliconiine eggs; and their extensive diversity of defence compounds called cyanogenic glucosides. However, the protection systems of Passiflora plants go beyond these three features. Trichomes, mimicry of pathogen infection through variegation, and production of extrafloral nectar to attract ants and other predators of their herbivores, are morphological defences reported in this plant genus. Moreover, Passiflora plants are well protected chemically, not only by cyanogenic glucosides, but also by other compounds such as alkaloids, flavonoids, saponins, tannins and phenolics. Heliconiines can synthesize cyanogenic glucosides themselves, and their ability to handle these compounds was probably one of the most crucial adaptations that allowed the ancestor of these butterflies to feed on Passiflora plants. Indeed, it has been shown that Heliconius larvae can sequester cyanogenic glucosides and alkaloids from their host plants and utilize them for their own benefit. Recently, it was discovered that Heliconius adults have highly accurate visual and chemosensory systems, and the expansion of brain structures that can process such information allows them to memorize shapes and display elaborate pre-oviposition behaviour in order to defeat visual barriers evolved by Passiflora species. Even though the heliconiine-Passiflora model system has been intensively studied, the forces driving host-plant preference in these butterflies remain unclear. New studies have shown that host-plant preference seems to be genetically controlled, but in many species there is some plasticity in this choice and preferences can even be induced. Although much knowledge regarding the coevolution of Passiflora plants and heliconiine butterflies has accumulated in recent decades, there remain many exciting unanswered questions concerning this model system.

Anthocyanin Contents Enhancement with Gamma Irradiated Mutagenesis in Blackberry (Rubus fructicosus)

Effects of radiation processing on the endogenous phytochemical production in blackberry ( Rubus fructicosus L.) were investigated through a metabolites analysis, using high-performance liquid chromatography with a diode array detector and a triple quadrupole mass spectrometer (HPLC-DAD-ESI-MS/MS). Four mutant cultivar lines (B, C, D, and E) were developed through the treatment of various doses of gamma irradiation (80, 60, 40, and 20 Gy) on the control blackberry cultivar (V3). These mutant cultivar lines were selected according to their different morphological variations in leaf shape and branch color. In the present study, we performed quantitative analyses of the four standard compounds in blackberry mutant cultivars: cyanidin-3- O-glucoside, cyanidin-3- O-xyloside, cyanidin-3- O-malonylglucoside, and cyanidin-3- O-dioxalylglucoside. The HPLC fingerprints displayed different profiles for six blackberry cultivar lines, demonstrating that the accumulation of total anthocyanins was affected by the gamma irradiation. The contents of cyanidin-3- O-glucoside and cyanidin-3- O-xyloside were high in the gamma-irradiated mutant cultivars of blackberries, compared to those of the control cultivar (V3) and the cross breeding cultivar ( R. fructicosus × R. parvifolius; CB). Cyanidin-3- O-malonylglucoside and cyanidin-3- O-dioxalylglucoside were also analyzed for their quantification in six cultivar lines, as metabolites contributing to the discrimination of six cultivar lines. Among gamma irradiated mutant blackberry cultivars, the highest dose level of gamma irradiation (80 Gy) resulted in the highest cyanidin-3- O-glucoside content enhancement. Therefore, these results can be useful to determine the optimized gamma irradiated value at which anthocyanins reaches an abundant level in Rubus species.

Taxonomic Study of Japanese Deparia petersenii (Woodsiaceae) Based on Cytological and Molecular Information

Deparia petersenii has a large morphological variation in plant size and leaf shape in Japan. To reveal possible distinct biological units of this species, we determined the chromosome numbers and nuc

Digital Morphometrics of Two North American Grapevines (Vitis: Vitaceae) Quantifies Leaf Variation between Species, within Species, and among Individuals.

Recent studies have demonstrated that grapevine (Vitis spp.) leaf shape can be quantified using digital approaches which indicate phylogenetic signal in leaf shape, discernible patterns of developmental context within single leaves, and signatures of local environmental conditions. Here, we extend this work by quantifying intra-individual, intraspecific, and interspecific variation in leaf morphology in accessions of North American Vitis riparia and V. rupestris in a common environment. For each species at least four clonal replicates of multiple genotypes were grown in the Missouri Botanical Garden Kemper Center for Home Gardening. All leaves from a single shoot were harvested and scanned leaf images were used to conduct generalized Procrustes analysis, linear discriminant analysis, and elliptical Fourier analysis. Leaf shapes displayed genotype-specific signatures and species distinctions consistent with taxonomic classifications. Leaf shape variation within genotypes and among clones was the result of pest and pathogen-induced leaf damage that alters leaf morphology. Significant trends in leaf damage caused by disease and infestation were non-random with respect to leaf position on the shoot. Digital morphometrics is a powerful tool for assessing leaf shape variation among species, genotypes, and clones under common conditions and suggests biotic factors such as pests and pathogens as important drivers influencing leaf shape.

ギョウジャニンニクの変異と選抜 : 2. 実生集団における葉形変異とその年次間相関について

ギョウジャニンニクの変異と選抜 : 2. 実生集団における葉形変異とその年次間相関について

Mapping morphological shape as a high-dimensional functional curve.

Detecting how genes regulate biological shape has become a multidisciplinary research interest because of its wide application in many disciplines. Despite its fundamental importance, the challenges of accurately extracting information from an image, statistically modeling the high-dimensional shape and meticulously locating shape quantitative trait loci (QTL) affect the progress of this research. In this article, we propose a novel integrated framework that incorporates shape analysis, statistical curve modeling and genetic mapping to detect significant QTLs regulating variation of biological shape traits. After quantifying morphological shape via a radius centroid contour approach, each shape, as a phenotype, was characterized as a high-dimensional curve, varying as angle θ runs clockwise with the first point starting from angle zero. We then modeled the dynamic trajectories of three mean curves and variation patterns as functions of θ. Our framework led to the detection of a few significant QTLs regulating the variation of leaf shape collected from a natural population of poplar, Populus szechuanica var tibetica. This population, distributed at altitudes 2000-4500m above sea level, is an evolutionarily important plant species. This is the first work in the quantitative genetic shape mapping area that emphasizes a sense of 'function' instead of decomposing the shape into a few discrete principal components, as the majority of shape studies do.

In Vitro Enhancement of Bacoside in Brahmi (Bacopa monnieri) Using Colchicine

Present investigation on in vitro effects of two levels of colchicine (0.1% and 0.2%) for 1, 2, 3, 4 and 5 hours treatment on leaf explants of Brahmi (Bacopa monnieri) collected from Paithan (Aurangabad) was conducted with a view to induce somaclonal variations and enhancement in the bacoside content in regenerated plants. Bramhi plants regenerated through previously treated leaf explants with colchicine showed morphological variations in leaf shape, number of leaves per node, leaf arrangement, etc. and enhance the bacoside content. 0.2% colchicine treatment for 5 hours showed maximum variations in number of leaves per node under in vitro conditions; however, these variations were not continued after subculture. While the 0.1% colchicine treatment for 2 hours significantly increase the bacoside content up to 0.72% i.e., more than four folds to the in vitro regenerated Brahmi plants without colchicine treatments.

Evaluation of different blueberry genotypes under mid-hill conditions of Himachal Pradesh

Southern highbush blueberry genotypes, namely, Gulf Coast, Jewel, Misty, Sharpblue and two rabbiteye genotypes, viz., Alapaha and Austin were evaluated for growth, flowering and fruiting behavior under mid hill conditions of Himachal Pradesh during 2014–16. The variability among genotypes was observed for their growth habit, foliar characteristics, flowering and fruit quality attributes. Genotype, Misty exhibited single stem trunk with spreading and upright growth habit, whereas, all other genotypes including rabbiteye exhibited multi-stem trunk. However, southern highbush genotype Jewel had more spreading growth habit with vigorous cane having wide crotch angle as compared with other genotypes. In Alapaha, the bush structure was more compact with upright branching having thin and week cane growth. The genotypes also exhibited great variation in leaf shape, colour and size. The variation in flowering and fruiting behavior was also observed among them, Gulf Coast and Misty were earliest to bloom, while Austin was last. Similarly, Gulf Coast and Misty were the earliest in berry maturity. First picking date in Gulf Coast and Misty was on April 25 and harvesting was continued upto first week of May, while Austin was last (last week of May to first week of June). There was also a great variation in the physico-chemical properties of berries among cultivars. The pooled data of three years showed maximum (1.83 g) berry weight in Jewel whereas; Austin produced smallest berries (0.98 g). Similarly, the total soluble solids and titratable acid contents also varied significantly. All genotypes including rabbiteye type had TSS content more than 10% which has been reported as minimum quality index in blueberries. Based on this study it can be concluded that all southern highbush blueberry genotypes as well as two rabiteye genotypes were found promisisg and thus can be grown in northern parts of India where soil is acidic and winter is cool enough to meet-out the chilling requirements.

Morphometric analysis of Passiflora leaves: the relationship between landmarks of the vasculature and elliptical Fourier descriptors of the blade.

Background: Leaf shape among Passiflora species is spectacularly diverse. Underlying this diversity in leaf shape are profound changes in the patterning of the primary vasculature and laminar outgrowth. Each of these aspects of leaf morphology—vasculature and blade—provides different insights into leaf patterning. Results: Here, we morphometrically analyze >3300 leaves from 40 different Passiflora species collected sequentially across the vine. Each leaf is measured in two different ways: using 1) 15 homologous Procrustes-adjusted landmarks of the vasculature, sinuses, and lobes; and 2) Elliptical Fourier Descriptors (EFDs), which quantify the outline of the leaf. The ability of landmarks, EFDs, and both datasets together are compared to determine their relative ability to predict species and node position within the vine. Pairwise correlation of x and y landmark coordinates and EFD harmonic coefficients reveals close associations between traits and insights into the relationship between vasculature and blade patterning. Conclusions: Landmarks, more reflective of the vasculature, and EFDs, more reflective of the blade contour, describe both similar and distinct features of leaf morphology. Landmarks and EFDs vary in ability to predict species identity and node position in the vine and exhibit a correlational structure (both within landmark or EFD traits and between the two data types) revealing constraints between vascular and blade patterning underlying natural variation in leaf morphology among Passiflora species.

Microspore Induced Doubled Haploids Production from Ethyl Methanesulfonate (EMS) Soaked Flower Buds Is an Efficient Strategy for Mutagenesis in Chinese Cabbage.

Chinese cabbage buds were soaked with Ethyl methanesulfonate (EMS) to induce mutagenesis. The influence of different EMS concentrations and treatment durations on microspore development, embryo production rate and seedling rate were evaluated in five Chinese cabbage genotypes. Mutations in four color-related genes were identified using high resolution melting (HRM) curves of their PCR products. The greatest embryo production and seedling rates were observed when buds were treated with 0.03 to 0.1% EMS for 5 to 10 min, while EMS concentrations greater than 0.1% were lethal to the microspores. In total, 142 mutants with distinct variations in leaf shape, leaf color, corolla size, flower color, bolting time and downy mildew resistance were identified from 475 microspore culture derived Doubled Haploids. Our results demonstrate that microspore derived Doubled Haploids from EMS soaked buds represents an efficient approach to rapidly generate homozygous Chinese cabbage mutants.

Quantitative gene-gene and gene-environment mapping for leaf shape variation using tree-based models.

Leaf shape traits have long been a focus of many disciplines, but the complex genetic and environmental interactive mechanisms regulating leaf shape variation have not yet been investigated in detail. The question of the respective roles of genes and environment and how they interact to modulate leaf shape is a thorny evolutionary problem, and sophisticated methodology is needed to address it. In this study, we investigated a framework-level approach that inputs shape image photographs and genetic and environmental data, and then outputs the relative importance ranks of all variables after integrating shape feature extraction, dimension reduction, and tree-based statistical models. The power of the proposed framework was confirmed by simulation and a Populus szechuanica var. tibetica data set. This new methodology resulted in the detection of novel shape characteristics, and also confirmed some previous findings. The quantitative modeling of a combination of polygenetic, plastic, epistatic, and gene-environment interactive effects, as investigated in this study, will improve the discernment of quantitative leaf shape characteristics, and the methods are ready to be applied to other leaf morphology data sets. Unlike the majority of approaches in the quantitative leaf shape literature, this framework-level approach is data-driven, without assuming any pre-known shape attributes, landmarks, or model structures.

Genome-wide Identification of TCP Family Transcription Factors from Populus euphratica and Their Involvement in Leaf Shape Regulation.

Higher plants have been shown to experience a juvenile vegetative phase, an adult vegetative phase, and a reproductive phase during its postembryonic development and distinct lateral organ morphologies have been observed at the different development stages. Populus euphratica, commonly known as a desert poplar, has developed heteromorphic leaves during its development. The TCP family genes encode a group of plant-specific transcription factors involved in several aspects of plant development. In particular, TCPs have been shown to influence leaf size and shape in many herbaceous plants. However, whether these functions are conserved in woody plants remains unknown. In the present study, we carried out genome-wide identification of TCP genes in P. euphratica and P. trichocarpa, and 33 and 36 genes encoding putative TCP proteins were found, respectively. Phylogenetic analysis of the poplar TCPs together with Arabidopsis TCPs indicated a biased expansion of the TCP gene family via segmental duplications. In addition, our results have also shown a correlation between different expression patterns of several P. euphratica TCP genes and leaf shape variations, indicating their involvement in the regulation of leaf shape development.

KNAT3/4/5-like class 2 KNOX transcription factors are involved in Medicago truncatula symbiotic nodule organ development.

We investigated the role of KNOX genes in legume root nodule organogenesis. Class 1 KNOX homeodomain transcription factors (TFs) are involved in plant shoot development and leaf shape diversity. Class 2 KNOX genes are less characterized, even though an antagonistic function relative to class 1 KNOXs was recently proposed. In silico expression data and further experimental validation identified in the Medicago truncatula model legume three class 2 KNOX genes, belonging to the KNAT3/4/5-like subclass (Mt KNAT3/4/5-like), as expressed during nodulation from early stages. RNA interference (RNAi)-mediated silencing and overexpression studies were used to unravel a function for KNOX TFs in nodule development. Mt KNAT3/4/5-like genes encoded four highly homologous proteins showing overlapping expression patterns during nodule organogenesis, suggesting functional redundancy. Simultaneous reduction of Mt KNAT3/4/5-like genes indeed led to an increased formation of fused nodule organs, and decreased the expression of the MtEFD (Ethylene response Factor required for nodule Differentiation) TF and its direct target MtRR4, a cytokinin response gene. Class 2 KNOX TFs therefore regulate legume nodule development, potentially through the MtEFD/MtRR4 cytokinin-related regulatory module, and may control nodule organ boundaries and shape like class 2 KNOX function in leaf development.

English

There is low production of okra in Ghana due to lack of improved varieties and biotic constraints. This study was conducted to characterize okra genotypes to predict genetic variation in the crop. Field trial was conducted to determine genetic variability in 21 okra genotypes. The experiment was based on the randomized complete block design (RCBD) involving planting distance of 0.6 × 0.6 m. Thirty-one quantitative and qualitative data were used to generate a dendrogram. Variations in leaf shape, leaf rib colour, petiole colour, petal colour, colour of the darkest ridges and stem colour were distinctive among the okra genotypes. The mean plant height, canopy diameter, leaf length and breadth, petiole length, internode length, number of branches, days to 50% flowering and fruit yield differed significantly (p ≤ 0.05) among the 21 okra genotypes. These were discriminated into three clusters in a dendrogram with GH3731 as the most diverse. UCCC1, UCCC2, UCCC3, UCCC4 and UCCC5 appeared genetically similar with low fruit yield but early maturity. However, GH5332 had a significantly (p ≤ 0.05) the highest fruit yield of 11.88 t ha-1 but late maturing. UCCC5 or similar genotypes with early maturity trait can be hybridized with GH5332 to improve the yield and earliness. Key words: Breeding, germplasm, genotypes, genetic diversity and hybridization.

Expression profiles of miRNAs in the genesis of Populus euphratica Oliv. heteromorphic leaves

The poplar species Populus euphratica Oliv. exhibits a typical heterophylly; lanceolate and broad-oval leaves grow on young and adult trees, respectively. It is therefore an ideal model species for studying leaf shape development. MicroRNAs (miRNAs) have important regulatory functions in plant growth and development, such as the developmental regulation of adaxial–abaxial polarity. To investigate the miRNAs involved in the development of the apical–basal and medial–lateral axes of P. euphratica leaves, an unfolded piece method and microscopy measuring techniques were employed to study the leaf shape variations between lanceolate and broad-oval leaves within buds. We found that the leaf shape of P. euphratica is determined between the first and the third or fifth macroscopic leaf during the germination period. The first three tender leaves of lanceolate and broad-oval leaf buds were obtained to construct six cDNA libraries from small RNAs. MicroRNAs were identified using high-throughput sequencing, and 165 novel miRNAs were found. By comparing the expression levels of the miRNAs between these two kinds of samples (lanceolate and broad-oval leaves), we found that nine miRNAs (six novel miRNAs and three conserved miRNAs) and their 113 target genes are involved in the development of the apical–basal and medial–lateral axes. The expression profiles of these miRNAs and their targets were further validated by quantitative reverse transcription polymerase chain reaction. Moreover, functional information on the targets was annotated using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases.

Butterfly Learning and the Diversification of Plant Leaf Shape

Visual cues are important for insects to find flowers and host plants. It has been proposed that the diversity of leaf shape in Passiflora vines could be a result of negative frequency dependent selection driven by visual searching behavior among their butterfly herbivores. Here we tested the hypothesis that Heliconius butterflies use leaf shape as a cue to initiate approach towards a host plant. We first tested for the ability to recognize shapes using a food reward conditioning experiment. Butterflies showed an innate preference for flowers with three and five petals. However, they could be trained to increase the frequency of visits to a non-preferred flower with two petals, indicating an ability to learn to associate shape with a reward. Next we investigated shape learning specifically in the context of oviposition by conditioning females to lay eggs on two shoots associated with different artificial leaf shapes: their own host plant, Passiflora biflora, and a lanceolate non-biflora leaf shape. The conditioning treatment had a significant effect on the approach of butterflies to the two leaf shapes, consistent with a role for shape learning in oviposition behavior. This study is the first to show that Heliconius butterflies use shape as a cue for feeding and oviposition, and can learn shape preference for both flowers and leaves. This demonstrates the potential for Heliconius to drive negative frequency dependent selection on the leaf shape of their Passiflora host plants.

The significance of shared leaf shape in Alseuosmia pusilla and Pseudowintera colorata

Leaf shape, size, and colour are used by herbivores to identify sources of palatable foliage for food. It is possible, therefore, that an undefended plant might gain protection from herbivores by matching leaf characteristics of a chemically defended species. We demonstrate the use of a geometric morphometric approach to quantify spatial variation in leaf shape and size across populations of Pseudowintera colorata (Raoul) Dandy, and a putative Batesian mimic, Alseuosmia pusilla (Colenso) A. Cunningham. These are unrelated, sympatric species that, to the human eye, bear strikingly similar foliage. Using the Cartesian coordinates of leaf margins as descriptors of leaf shape, we found that in the chemically defended P. colorata, leaves were morphologically distinct from all of the neighbouring species except for the undefended A. pusilla. Alseuosmia pusilla individuals were more similar to neighbouring than to distant P. colorata, and 90% of leaf shape variation in the two species varied similarly across an altitudinal gradient. The data are consistent with Batesian mimicry, wherein the conspicuous characteristic of a defended model is replicated by an undefended mimic across its entire growing range. Our study provides the first detailed and powerful quantitative leaf shape evidence of leaf shape being matched between an undefended plant species to a chemically defended unrelated species across a shared growing range, and highlights the importance of using a spatially explicit morphometric method when investigating leaf shape, especially in relation to plant mimicry.