Taxonomic Significance of Seed Morphology in Veronica L. (Plantaginaceae) Species from Central Europe

In this study, 1159 seeds of 29 Central European species of the genus Veronica were analyzed based on scanning electron microscopy images. The species belonged to nine subgenera: Beccabunga, Chamaedrys, Cochlidiosperma, Pellidosperma, Pentasepalae, Pocilla, Pseudolysimachium, Stenocarpon and Veronica, following the newest phylogenetic classification of the genus. Nine measured characteristics of seeds and nine ratios were analyzed statistically using ANOVA followed by post hoc testing, cluster analysis and discriminant analysis. In most cases, the results were not congruent with the contemporary classification of the genus. Examinations of qualitative seed features by scanning electron microscopy included the cochlidiospermous or discoid seed type, the seed shape, the general sculpture of the seed coat surface, the sculpture of anticlinal and periclinal walls and some species-specific traits such as the presence of the epidermal appendix. All these features, apart from seed shape, were useful to distinguish all subgenera and some species within subgenera: Beccabunga, Chamaedrys, Pellidosperma, Pocilla (only V. filiformis) and Veronica. The identification key based on the seed micromorphological features was prepared.

Seed Macro- And Micro-Morphology of Some Species Of Kickxia Dumort, Scrophularia L. And Plantago L. From Saudi Arabia

The seed macro- and micro-morphological characters of 13 species belonging to three genera; Kickxia Dumort, Scrophularia L. and Plantago L., collected from different localities of Saudi Arabia, were studied using a Stereomicroscope and Scanning Electron Microscope for evaluating their taxonomic relationships. Three macro-morphological characters of seeds were shape, size, and color while three diagnostic micromorphological characters were seed coat sculpture, the anticlinal and periclinal wall., The seed shape seems to be specific in Plantago L. (peltate, angled) than the two other genera while the color and seed size show little importance. The Plantago L. has a specific rugose sculpture while the other two genera have either tuberculate or alveolate. So Plantago L. was possessed no affinities to Kickxia Dumor or Scrophularia L.. This observation gives extra support to the earlier taxonomic views that suggested the retention of two genera in the traditional family Scrophulariaceae and maintaining Plantago L. in a separate monogeneric family Plantaginaceae Detailed analysis of seed characters of more species is needed to clarify the systematic relationships between the three genera. A key to the identification of studied species based on seed micro- and macro-morphological characters is provide. Bangladesh J. Plant Taxon. 28(2): 385-393, 2021 (December)

New Techniques for Seed Shape Description in Silene Species

Seed shape in Silene species is often described by means of adjectives such as reniform, globose, and orbicular, but the application of seed shape for species classification requires quantification. A method for the description and quantification of seed shape consists in the comparison with geometric models. Geometric models based on mathematical equations were applied to characterize the general morphology of the seeds in 21 species of Silene. In addition to the previously described four models (M1 is the cardioid, and M2 to M4 are figures derived from it), we present four new geometric models (model 5–8). Models 5 and 6 are open cardioids that resemble M3, quite different from the flat models, M2 and M4. Models 7 and 8 were applied to those species not covered by models 2 to 6. Morphological measures were obtained to describe and characterize the dorsal view of the seeds. The analyses done on dorsal views revealed a notable morphological diversity and four groups were identified. A correlation was found between roundness of dorsal view and the geometric models based on lateral views, such that some of the groups defined by seed roundness are also characterized by the similarity to particular models. The usefulness of new morphological tools of seed morphology to taxonomy is discussed.

Characterization of Pigeonpea Genotypes Based on DUS Traits

The research entails morphological characterization of pigeonpea genotypes based on qualitative traits which aids in varietal description and ensure genetic purity. The study was conducted at the Department of Pulses, Tamil Nadu Agricultural University during kharif, 2019 and rabi, 2019-2020. The experiment was conducted in Randomized complete block design with two replications. The 68-short duration pigeonpea genotypes were characterized and grouped based on 17 qualitative traits. The morphological characterization revealed that, more variation was identified for traits viz., pattern of streaks on standard petal, plant height, seed colour, seed shape and seed size. Sixty - eight genotypes were subjected to cluster analysis and were grouped into four major clusters with an average similarity of 80%. The similarity coefficient ranged from 0.65 to 1.00. The cluster I consisted of 60 genotypes. Two sub-groups were formed from Cluster I. The sub-group I had 59 genotypes at 84 per cent similarity, whereas the sub-group II consisted of the genotype ICPL19050. Cluster II was made up of six genotypes. The cluster II was divided into two sub-groups at 84 per cent similarity. Clusters III and IV were solitary clusters, each with a single genotype. The characterization of genotypes with specific traits could be used to identify the genotypes, maintenance of genetic purity and to utilize in future breeding programmes.

Geometric Models for Seed Shape Description and Quantification in the Cactaceae

Seed shape in species of the Cactaceae is described by comparison with geometric models. Three new groups of models are presented, two for symmetric seeds, and a third group for asymmetric seeds. The first two groups correspond, respectively, to superellipses and the combined equations of two semi-ellipses. The third group contains models derived from the representation of polar equations of Archimedean spirals that define the shape of asymmetric seeds in genera of different subfamilies. Some of the new models are geometric curves, while others are composed with a part resulting from the average silhouettes of seeds. The application of models to seed shape quantification permits the analysis of variation in seed populations, as well as the comparison of shape between species. The embryos of the Cactaceae are of the peripheral type, strongly curved and in contact with the inner surface of the seed coat. A relationship is found between seed elongation and the models, in which the genera with elongated seeds are represented by models with longer trajectories of the spiral. The analysis of seed shape opens new opportunities for taxonomy and allows quantification of seed shape in species of the Cactaceae.

Genetic Variability of Tunisian Faba Beans (Vicia faba L.) Based on Seeds’ Morphophysical Properties as Assessed by Statistical Analysis

Faba bean (Vicia faba L.) is a legume crop cultivated for its nutritious seeds that are an important worldwide source of human food and feed. Seeds characterization is a prerequisite step for faba bean quality improvement. The morphophysical characterization of the seeds of twenty-four local faba bean accessions following the UPOV descriptors and the AOAC International standards was carried out and assessed with an approach based on Euclidean statistical model. “205 Bulk” was the unique accession harboring white hilum color seed which is linked to low convicine grain content. Irregular seed shape was the most observed character among the studied accessions except “Badii” displaying an elliptical seed shape; therefore, seed shape did not allow discrimination within our Tunisian germplasm. Interestingly, the physical characters of the seeds showed significant diversity between the accessions for all the measured parameters. A highly significant variability was observed for axial, length, and width dimensions of seeds, with “Memdouh” being the longest and largest seed accession, whereas “01-02” was the shortest and narrowest. Classification of the studied faba bean germplasm accessions based on morphophysical characters using clustering by Euclidean distance revealed three different groups. Moreover, multivariate PCA analysis further classified the faba bean accessions into four main clusters. Correlation study performed by using Spearman’s test established positive correlations within physical parameters of seeds such as between mean length and mean width of seeds. Therefore, using morphophysical parameters screening, valuable phenotypes have been selected for deeper physiological characterization and further breeding programs.

Genetic diversity of the Algerian peanut population analyzed using morphological markers and seed storage proteins

Background. The peanut is one of the most important oil crops suitable for cultivation in the tropical areas of the world. Despite its agronomic importance, few studies have been carried out to assess the morphogenetic diversity of Arachis hypogaea L., especially in East African countries. The major interest of this morphologic study lies in the potential of this species to provide useful genes for the improvement of cultivated peanuts. To date, no study has been performed in Algeria to characterize local peanut varieties.Materials and methods. Thirty peanut accessions were collected from four principal areas of peanut production in Algeria. Genetic characterization using 15 agronomic characters and 25 morphological descriptors showed a high level of diversity among accessions. Principal Component Analysis and the Hierarchical Ascendant Classification were made to clarify the genetic relationship between peanut accessions.Results and discussion. Results showed that leaflet size (length and width), seed shape and size, oil content, and branching pattern were the principal characters to discriminate the screened A. hypogaea accessions. In addition to that, the weights of 10 pods and 100 seeds were the most variable traits and presented a CV of 42.53% and 40.12%, respectively. On the other hand, total storage proteins extracted were separated using SDS-PAGE and revealed thirty bands that were used to generate a matrix and make a cluster analysis using the UPGMA method, exhibiting different storage proteins compositions. Moreover , the phenotypic diversity observed agrees with the storage protein profile diversity, while the accessions grouped in similar clusters belong to the two subspecies of A. hypogaea. The results of the current study show that morphological traits and seed storage proteins can be useful for exploring the diversity among A. hypogaea accessions.

Seed micromorphology and anatomy of 36 Muscari (Asparagaceae) taxa from Turkey with notes on their systematic importance

This study presents the first in-depth evaluation of the morphological and anatomical characters, as well as their taxonomic importance, of the seeds of 36 taxa in subgenera Muscari, Leopoldia, Pseudomuscari and Botryanthus of the genus Muscari in Turkey, where 24 of the taxa are endemic. The results indicate that the taxa generally differ from each other in terms of seed shape and dimension. Seed dimensions vary between 1.66 mm and 3.21 mm in length, and between 1.12 mm and 2.63 mm in width. The seed surface ornamentation is grouped into nine forms: ruminate, reticulate, reticulate-areolate, reticulate-foveate, alveolate, scalariform, rugose, verrucate and areolate. The most common type is ruminate, while areolate, reticulate-foveate and scalariform ornamentation forms were found to be taxon-specific. Testa structures of the taxa examined consist in general of two different layers: the epidermis and the subepidermis in scleranchymatous or parenchymatous structures. The subepidermis may be absent in some of taxa. The structure and thickness of the epidermis and the subepidermis are very important characteristics that disclose interspecific relations among the examined taxa. We also provide a key for the identification of the studied taxa based on seed features.

Evaluation of Traits Associated With Seed Characteristics in Arkansas Restorer Lines

Rice Grain dimension and weight are two critical factors for marketing and increasing yield capacity. Seed shape is measured by its length, width, thickness, and ratio of length-width. In this study, an experiment was conducted in a controlled condition from fall 2017 to 2020 to identify QTL and candidate genes associated with seed dimension and weight using a bi-parental population resulting from two University of Arkansas developed genotypes: a restorer line 367R and an advanced breeding line RU1501139, in Stuttgart, Arkansas. Five seed dimension traits, including seed length, seed width, seed thickness, seed length-width ratio, and 100-seeds weight, were obtained for QTL detection. The study detected a total of 17 QTL. Four QTL associated with seed length were identified, in which two were positioned on chr. 3, one on chr. 7, and one on chr. 11. Two QTL related to seed length-width ratio were detected on chr. 3 and 7. Whereas a total of three QTL were identified for seed thickness, one each on chr. 5, 6, and 8. Eight QTL associated with seed weight were found, of which four QTL were detected on chr. 12, two each on chr. 1 and 10, and one on chr. 3. Of 17 QTL, four QTL originated from RU1501139, while the origin of the other 13 QTL was 367R. Since multiple genes could control the yield and seed physical characteristics, the detected QTL can play a role in introducing superior parental lines for developing conventional and hybrid rice production.

Seed Geometry in the Vitaceae

The Vitaceae Juss., in the basal lineages of Rosids, contains sixteen genera and 950 species, mainly of tropical lianas. The family has been divided in five tribes: Ampelopsideae, Cisseae, Cayratieae, Parthenocisseae and Viteae. Seed shape is variable in this family. Based on new models derived from equations representing heart and water drop curves, we describe seed shape in species of the Vitaceae. According to their similarity to geometric models, the seeds of the Vitaceae have been classified in ten groups. Three of them correspond to models before described and shared with the Arecaceae (lenses, superellipses and elongated water drops), while in the seven groups remaining, four correspond to general models (waterdrops, heart curves, elongated heart curves and other elongated models) and three adjust to the silhouettes of seeds in particular genera (heart curves of Cayratia and Pseudocayratia, heart curves of the Squared Heart Curve (SqHC) type of Ampelocissus and Ampelopsis and Elongated Superellipse-Heart Curves (ESHCs), frequent in Tetrastigma species and observed also in Cissus species and Rhoicissus rhomboidea). The utilities of the application of geometric models for seed description and shape quantification in this family are discussed.