Leaf Margin Shape Research Articles

Pollen morphology and anatomy of Rubus L. (Rosaceae) in Thailand

Pollen morphology and anatomy were investigated in 19 species of the genus Rubus L. from Thailand by observation and analysis under a light microscope and a scanning electron microscope. The pollen grains are monads, with radial symmetry, circular shaped in polar view and isopolar. The sizes of the pollen grains are small and medium. Considering the species studied, the majority have medium sized pollen grains. There were different shapes detected viz., oblate, suboblate, prolate spheroidal, oblate spheroidal and prolate. The pollen grains have various apertures: tricolporate, tricolporate-tetracolporate, tricolpate and tricolpate-tetracolpate. There were five forms of exine sculpturing as follows: rugulate-perforate, striate-perforate, microverrucate-perforate, microverrucate and perforate. In the genus Rubus it is not possible to use the morphology of the pollen for the identification to species level. Eleven species had the morphology of the pollen studied for the first time. The anatomy of the leaf, petiole and stem were observed by transverse section. The anatomy can be used for the identification to species level. The results indicate that the anatomical characteristics used for the identification key are shape of leaf margin, shape of adaxial surface of midrib, pericyclic fibers, idioblast cell, shape of petiole, starch grain, number of vascular bundles, shape of stem and types of trichomes. In this study, the anatomy of 19 species was reported for the first time. The numerical analysis based on the pollen morphology and anatomy data did not support classification of the genus Rubus L.

Morphological characterization of Indian pummelo (Citrus maxima)

The present study was conducted with the aim to characterize different indigenous pummelo genotypes based on 19 quantitative and 9 qualitative traits. Leaf shape, leaf margin shape, leaf apex shape, petiole wing, petiole wing shape, fruit shape, fruit apex shape, fruit axis, fruit surface texture and pulp colour were the main qualitative characters of study. The higher coefficients of variation were determined for petiole area (36.33%), juice quantity (17.38%), leaf area (14.50%) and fruit weight (14.22%). Principal component analysis (PCA) for quantitative traits indicated that six PCA had Eigen-value greater than one. The cumulative variation explained by six components, viz. leaf length, fruit width, leaf length: width ratio, leaf area, petiole area and lamina wing ratio accounted over 86.12 % variability. However, the result of the PCA for qualitative traits showed that three parameters namely leaf shape, leaf margin shape and leaf apex shape among 10 Principal Component Axis (PCA) had Eigen-values greater than one, and accounted for over 70.23% of the total variability. Based on PCA and coefficient of variation, traits like fruit weight, seed content, juice content, leaf and petiole area, leaf length, leaf width and leaf length: width ratio had significant involvement in pummelo diversity, and can be used in differentiating accessions of citrus.

Revision of Alnus (Betulaceae) in Iran using molecular ITS markers and morphological characteristics

Alnus (Alder) is a genus of Betulaceae, which comprises more than 29 species in the world. According to different classifications of flora, eight taxa of the genus naturally grow in Iran and are distributed along the northern slope of Albourz Mountains in Iran (Hyrcanian forests). In the current research, we investigated morphological characteristics and phylogenetic relationships of 31 populations of the genus in Iran. Twenty-eight qualitative and quantitative traits were studied for morphological evaluation and ITS molecular marker was investigated for molecular study. We used MVSP, SPSS, MrBayes, RAXMLGUI, Mesquite 2.71, Modeltest 3.7 software packages for statistical analyses. Morphological features varied widely among the studied taxa and ANOVA test revealed significant difference for most of them. Moreover, the angle of leaf base, the leaf margin shape, the length and width of the leaf blade, fruits length, and the presence of hair on the petioles, young twigs, and buds were more variable morphological traits. The studied taxa were clustered separately in the UPGMA tree, PCA and PCO plots using morphological traits. In addition, CA-joined plot showed each taxon to have distinct morphological trait(s), which is useful in the identification of the taxa. Phylogeny analysis revealed that Alnus genus is a monophyletic group. Furthermore, the studied taxa were clustered separately in phylogenetic dendrogram. According to morphological and ITS data, we listed ten taxa of the genus in Iran and introduced A. hyrcana and A. longiflorescentia as two new species from Hyrcanian forests of Iran.

Selection of Morphoagronomic Descriptors in Physalis angulata L. Using Multivariate Techniques

This study aimed at selecting determinant morphoagronomic descriptors to characterize and evaluate Physalis angulata L. germplasm. Twelve quantitative and twenty-two qualitative descriptors were analyzed in six accessions of P. angulata coming from the physalis germplasm collection belonging to the State University of Feira de Santana-BA. The selection and discharge of quantitative descriptors was based on the direct selection and on the Singh method, while qualitative descriptors were analyzed through entropy. The statistic analyses were carried out using the GENES and R programs. Ten quantitative descriptors were excluded through direct selection and five through the Singh method. However, only four descriptors were considered redundant by both methods: east-west fruit, weight of five ripe fruits, width of leaf blade and total soluble solids. Although the total soluble solids descriptor was appointed for discharge, it was included in the group of descriptors selected due to its importance in the characterization of physalis fruit. The list of minimum descriptors to describe physalis accessions comprised 15 descriptors: plant height, stem diameter, north-south fruits, number of fruits per plant, leaf blade length, internode length, fruit longitudinal length, fruit transversal length, total soluble solids, growth habit, stem color, leaf margin shape, unripe calyx color, unripe fruit shape and color. These were nine quantitive and six qualitative descriptors, respectively. The discharge of 55.88% of the descriptors did not cause significant loss of information and might allow the reduction of time and resources spent to characterize and evaluate physalis germplasm.

Reproducibility of fluctuating asymmetry measurements in plants: Sources of variation and implications for study design

Fluctuating asymmetry (FA), i.e. small, non-directional deviations from perfect symmetry in morphological characters, increases under genetic and/or environmental stress. Ecological and evolutionary studies addressing FA became popular in past decades; however, their outcomes remain controversial. The discrepancies might be at least partly explained by inconsistent and non-standardised methodology. Our aim was to improve the methodology of these studies by identifying factors that affect the reproducibility of FA measurements in plant leaves. Six observers used a highly standardised measurement protocol to measure FA using the width, area and weight of the same set of leaves of 10 plant species that differed in leaf size, shape of the leaf margin and other leaf traits. On average, 24% of the total variation in the data was due to measurement error. Reproducibility of measurements varied with the shape of leaf margin, leaf size, the measured character and the experience of the observer. The lowest reproducibility of the width of leaf halves was found for simple leaves with serrate margins and the highest for simple leaves with entire margins and for compound pinnate leaves. The reproducibility was significantly lower for the weight of leaf halves than for either their width or area, especially for plants with small leaves. The reproducibility was also lower for measurements made by experienced observers than by naïve observers. The size of press-dried leaves decreased slightly but significantly relative to fresh leaves, but the FA of press-dried leaves adequately reflected the FA of fresh leaves. In contrast, preservation in 60% ethanol did not affect leaf size, but it decreased the width-based values of FA to 89.3% of the values measured from fresh leaves. We suggest that although reproducibility of leaf FA measurements depends upon many factors, the shape of the leaf margin is the most important source of variation. We recommend, whenever possible, choosing large-leaved plants with entire leaf margins as model objects for studies involving measurements of FA using the width of leaf halves. These measurements should be conducted with high accuracy from images of fresh or press-dried leaves.

쥐손이풀속(쥐손이풀과)의 외부영양형질에 의한 계통분류학적 연구

Vegetative characters (e.g. habitat, root, ramification and habit of stem, phyllotaxy, leaf sape, shape of leaf margin, shape of division and lobe of division, number of division, thick and texture of leaf and shape of stipule) on 35 species of Asian Geranium were reviewed to discussion propriety of taxonomic character and evolutionary trends. Wilfordii group is characterized by three divided leaf, Farreri group was grown a high altitude, and Maculatum group is grouped by life cycle of anneal. Arrangement state of leaf is alternate type G, tripartitum, G. eriostemon, and G. erianthum is thought the more primitive than the other taxon, and regarded as more advanced group the sibiricum group and pseudosibiricum group which divided of leaf deeply. Shape of leaf, division degree of lobes, shape of leaf margin and number of division are considered a good identification characters because width of change are fixed between population.

Repeated evolution of dioecy from monoecy in Siparunaceae (Laurales).

Siparunaceae comprise Glossocalyx with one species in West Africa and Siparuna with 65 species in the neotropics; all have unisexual flowers, and 15 species are monoecious, 50 dioecious. Parsimony and maximum likelihood analyses of combined nuclear ribosomal ITS and chloroplast trnL-trnF intergenic spacer sequences yielded almost identical topologies, which were used to trace the evolution of the two sexual systems. The African species, which is dioecious, was sister to all neotropical species, and the monoecious species formed a grade basal to a large dioecious Andean clade. Dioecy evolved a second time within the monoecious grade. Geographical mapping of 6,496 herbarium collections from all species sorted by sexual system showed that monoecy is confined to low-lying areas (altitude < 700 m) in the Amazon basin and southern Central America. The only morphological trait with a strong phylogenetic signal is leaf margin shape (entire or toothed), although this character also correlates with altitude, probably reflecting selection on leaf shapes by temperature and rainfall regimes. The data do not reject the molecular clock, and branch lengths suggest that the shift to dioecy in the lowlands occurred many million years after the shift to dioecy in the ancestor of the Andean clade.