Pod Morphology Research Articles

Molecular, morphological, and morphometric evidence reveal a new, critically endangered rattlepod (Crotalaria, Fabaceae/Leguminosae, Papilionoideae) from tropical China.

Here, we describe a new species of Crotalaria L. discovered in Mengla County, Xishuangbanna Dai Autonomous Prefecture, Yunnan, China. The new species, Crotalariamenglaensis S.A.Rather, was confirmed by identifying diagnostic morphological characteristics, performing principal component analyses of phenotypic traits, and phylogenetic analyses based on nuclear ITS and plastid matK sequences. Phylogenetic analyses recovered the two accessions of the new species to be sister to C.bracteata Roxb. ex DC. In turn, these two species formed the sister clade to the two accessions of C.incana L. The morphometric analyses revealed that all three species were distinct, while the analyses of distinctive characters enabled unambiguous distinction of the new species by its growth habit, leaflets, flower structure and pod morphology. In contrast to the two related species, the new species is currently known only from ca. 100 mature individuals. Thus, this species is considered to be critically endangered.

Assessing Morphological Trait Variability in Moroccan Carob (Ceratonia siliqua L.) Ecotypes for Adaptive Breeding in Response to Climate Change and Sustainable Food Security

The study focused on the morphological diversity of pods and seeds from six ecotypes of carob tree (Ceratonia siliqua L.), originating from different regions of Morocco including Khemissat, Safi, Aït Attab, Berkane, Ouezzane, and Agadir. Thirty pods per ecotype were collected from 10 different trees. Measurements were taken to analyze the morphology of seeds and pods. The results revealed significant differences among ecotypes for most morphological characteristics such as pod length, pod width, pod thickness, total pod weight, pulp weight, total number of seeds in the pod, seed weight within the pod, seed length, seed width, seed thickness, single seed weight, and weight of 100 seeds. Correlation analysis revealed associations among different morphological measures, highlighting the influence of pod morphology on seed yield. Principal component analysis (PCA) and hierarchical clustering analysis confirmed the presence of two distinct groups of ecotypes: the first group comprising the ecotypes Agadir, Aït Attab, Safi, and Khemissat, while the second group included the ecotypes Berkane and Ouezzane. These results have significant implications for variety selection and improvement of carob tree cultivation, with significant potential to enhance food security in Mediterranean regions. By better understanding the impact of ecotype on morphological characteristics, selection efforts can be directed towards developing varieties better adapted to changing environmental conditions, thereby contributing to strengthening the resilience of agricultural systems face of climate change.

An updated description of Parkia barnebyana (Leguminosae: Caesalpinioideae, mimosoid clade) from Amazonian Venezuela and Brazil, and comparison with other species in sect. Parkia with erect capitula

SummaryAn updated description, including characters of the capitulum and fertile flowers, is provided for Parkia barnebyana. Originally recorded from southern Venezuela, this small canopy tree from igapó (blackwater flooded forest) is now also known by two collections from north-western Brazil. The capitula are yellow and held erect, with the fertile flowers uppermost; they are borne on short, robust, upright peduncles that arise from long compound inflorescence axes projecting directly above the crown. The structure and shape of the capitula place this species in pantropical sect. Parkia and its pod morphology suggests that it lies outside the largely Amazonian nitida-group; both conclusions are supported by a recent phylogenetic analysis. The indehiscent pods remain in the tree at maturity and most seeds are apparently removed by arboreal dispersers and vertebrate seed predators. Two other neotropical species in sect. Parkia, P. cachimboensis and P. decussata, are known to have erect, yellow or largely yellow capitula and in both, a well-developed fringe of staminodia projecting from the basal flowers is absent. Both these species are chiropterophilous and although we predict that P. barnebyana is also likely to be bat-pollinated, we have made no observations. A fourth neotropical species, P. nana, also with yellow flowers, is reported to have erect capitula but they do have staminodial fringes; its pollination has not been studied. Within sect. Parkia, erect capitula occur only in the Neotropics, probably because of the head-down position in which quite large generalist phyllostomid bats land on them to access nectar. Erect capitula appear to have evolved more than once within neotropical sect. Parkia and at least sometimes from ancestors with pendent capitula, but further phylogenetic data are needed to confirm this.

Microscopical Analysis of Autofluorescence as a Complementary and Useful Method to Assess Differences in Anatomy and Structural Distribution Underlying Evolutive Variation in Loss of Seed Dispersal in Common Bean.

The common bean has received attention as a model plant for legume studies, but little information is available about the morphology of its pods and the relation of this morphology to the loss of seed dispersal and/or the pod string, which are key agronomic traits of legume domestication. Dehiscence is related to the pod morphology and anatomy of pod tissues because of the weakening of the dorsal and ventral dehiscence zones and the tensions of the pod walls. These tensions are produced by the differential mechanical properties of lignified and non-lignified tissues and changes in turgor associated with fruit maturation. In this research, we histologically studied the dehiscence zone of the ventral and dorsal sutures of the pod in two contrasting genotypes for the dehiscence and string, by comparing different histochemical methods with autofluorescence. We found that the secondary cell wall modifications of the ventral suture of the pod were clearly different between the dehiscence-susceptible and stringy PHA1037 and the dehiscence-resistant and stringless PHA0595 genotypes. The susceptible genotype had cells of bundle caps arranged in a more easily breakable bowtie knot shape. The resistant genotype had a larger vascular bundle area and larger fibre cap cells (FCCs), and due to their thickness, the external valve margin cells were significantly stronger than those from PHA1037. Our findings suggest that the FCC area, and the cell arrangement in the bundle cap, might be partial structures involved in the pod dehiscence of the common bean. The autofluorescence pattern at the ventral suture allowed us to quickly identify the dehiscent phenotype and gain a better understanding of cell wall tissue modifications that took place along the bean's evolution, which had an impact on crop improvement. We report a simple autofluorescence protocol to reliably identify secondary cell wall organization and its relationship to the dehiscence and string in the common bean.

Soybean Pod Morphology Classification Based on Machine Vision and Convolutional Neural Network

Pod morphology is one of the most crucial indicators for breeding high-quality soybeans. Therefore, the accurate classification of pod morphology is pivotal. Aiming at the problem that the morphology of soybean pods cannot be accurately classified, we proposed an automatic classification method based on machine vision and convolutional neural networks in this paper. First, we designed an image acquisition system to obtain soybean pod images. Then, a convolutional neural network model was designed to extract the deep features of soybean pods in the images. Finally, the deep feature training support vector machine (SVM) classifier was used to classify soybean pods of different forms, and the traditional features are designed to compare the morphological classification of soybean pods. The classification accuracies of this method were 98.8%, 99.2%, and 98.1% for straight, curved scythe, and bowhead bean pods, respectively, with an average classification accuracy of 98.7%, and the classification accuracy of deep features is 5.5% higher than that of traditional feature extraction. Experimental results prove that the proposed automatic classification method is feasible for soybean pod morphology classification, and it also has potential in classification of other characteristics of soybean, such as leaves, grains, and diseases.

Osodendron gen. nov. (Leguminosae, Caesalpinioideae), a new genus of mimosoid legumes of tropical Africa.

The genus Osodendron is here newly described to accommodate three species and one subspecies of African mimosoid legumes. These taxa have previously been included by several authors in Albizia, Cathormion and/or Samanea, but they have been shown to be phylogenetically unrelated to any of these, being instead the sister-group of the recently described Neotropical genus Robrichia, which is similar in vegetative morphology and especially its very similar indumentum, but is decidedly different in pod morphology. A taxonomic treatment of the three species in the genus is presented, with species descriptions, photographs, distribution maps and an identification key. The type species Osodendronaltissimum (Hook. f.) E.J.M. Koenen occurs in swamp and riverine rainforest and gallery forests, with the typical subsp. altissimum widespread across tropical Africa, while Osodendronaltissimumsubsp.busiraensis (G.C.C. Gilbert) E.J.M. Koenen is only known from the Busira river catchment in the western part of the Democratic Republic of Congo. Of the other two species, Osodendrondinklagei (Harms) E.J.M. Koenen is a common tree of rainforest and the forest-savannah transition including semi-deciduous and secondary forest as well as gallery forest and is restricted to Upper Guinea and the similar, but vegetatively more variable Osodendronleptophyllum (Harms) E.J.M. Koenen occupies comparable vegetation types in Lower Guinea and extends marginally into the Sudanian and Zambezian savannahs in gallery forest.

The Influence of Applications of Bio-Inputs Derived from Macroalgae and Bacteria on a Phaseolus vulgaris L. Crop

The common bean (Phaseolus vulgaris L.), is one of the most relevant legumes worldwide, as a source of protein, fiber, carbohydrates, and biologically important minerals. In recent decades, bean production increased significantly, especially in developing countries, where the availability of animal protein is often in short supply. However, a large portion of this agricultural production has been achieved in an unsustainable manner, through the intensive use of non-renewable agrochemicals, which in both the short and long term negatively affect soil fertility. To address this problem, the use of sustainable and renewable bio-inputs derived from macroalgae, and microorganisms may be amongst solutions required. Extracts of seaweeds have been shown to be biodegradable and non-toxic both for treated plants and consumers. This study aimed to evaluate the influence of the application of three bio-inputs made from different organisms on a common bean variety (BRSMG Realce) by analysing plant physiology and productivity, pod morphology, nutritional and mineral characterization of the bean. The study also aimed to evaluate the length of BRSMG Realce crop life cycle and compare its nutritional value with other commonly consumed varieties. Six treatments were performed: T0 - Control; T1 - Calmar® (soil - 100 kg/ha); T2 - Profertil® (foliar - 0.5%(v/v)); T3 - Albit® (leaf - 0.02%(v/v)); T4 - Calmar® ((100 kg/ha) + Profertil® (0.5%(v/v)); T5 - Calmar® ((100 kg/ha) + Albit® (0.02% (v/v)). The leaf chlorophyll index revealed significant increases for T2, T4 and T5, compared to control. In general, the treatments related to the pods morphology showed significant increases in the length/width ratio. In terms of productivity, significant increases were found with T1, T4 and T5. In the analysis of the nutritional value of dried beans there were significant increases in the contents of fiber in T1, protein in T4 and T5 and carbohydrates for T1, T2 and T3. For mineral composition, there were increases in the phosphorus content of T2, T4 and T5 beans. When the cooked beans were analysed, T4 and T1 produced a greater amount of ash and proteins, as compared to control. The applications of bio-inputs in the bean crop (Phaseolus vulgaris L.) exerted several positive and significant effects, mainly on the CCI, productivity, pod morphology as well as cooked bean nutritional values. It was verified that BRSMG Reakce has the potential to be included in the Portuguese diet.

Mechanism of pod shattering in the forage legume Medicago ruthenica

Pod shattering is a seed dispersal strategy and an important agronomical trait in domesticated crops. The relationship between pod shattering and pod morphology in the genus Medicago is well known; however, the detailed mechanism underlying pod dehiscence in Medicago ruthenica, a perennial legume used for forage production, is unknown. Here, the pod ventral sutures of shatter-resistant and shatter-susceptible M. ruthenica genotypes were examined at 8, 12, 16, and 20 d after flowering. The mechanism of pod shattering was analyzed through microscopic observations, polygalacturonase (PG) and cellulase (CE) activity analyses, and RNA-sequencing (RNA-Seq), and the results were verified via reverse transcriptase-quantitative polymerase chain reaction. Pod shattering at the ventral suture in M. ruthenica occurs via a combination of two mechanisms: degradation of the middle lamella at the abscission layers (ALs) and detachment of lignified cells on either side of the ALs triggered by physical forces. Increased PG and CE activities in the pod ventral suture are essential for AL cell-autolysis in the shatter-susceptible genotype. RNA-Seq revealed that 11 genes encoding PG and CE were highly expressed in the ventral sutures of the shatter-susceptible genotype. The expression levels of auxin biosynthesis-related genes decreased in the AL cells and they were negatively associated with pod dehiscence. These results enhance our understanding of the pod shattering mechanism not only in M. ruthenica but also in other leguminous plants.

A Core Set of Snap Bean Genotypes Established by Phenotyping a Large Panel Collected in Europe.

Snap beans are a group of bean cultivars grown for their edible immature pods. The objective of this work was to characterize the diversity of pod phenotypes in a snap bean panel (SBP), comprising 311 lines collected in Europe, and establish a core set (Core-SBP) with the maximum diversity of pod phenotypes. Phenotyping of the SBP was carried out over two seasons based on 14 quantitative pod dimension traits along with three qualitative traits: pod color, seed coat color, and growth habit. Phenotypes were grouped into 54 classes using a hierarchical method, and a Core-SBP with one line per phenotype class was established. A further field-based evaluation of the Core-SBP revealed higher diversity index values than those obtained for the SBP. The Core-SBP was also genotyped using 24 breeder-friendly DNA markers tagging 21 genomic regions previously associated with pod trait control. Significant marker-trait associations were found for 11 of the 21 analyzed regions as well as the locus fin. The established Core-SBP was a first attempt to classify snap bean cultivars based on pod morphology and constituted a valuable source of characteristics for future breeding programs and genetic analysis.

Studies on Effect of Mutagens on Quantitative Characters in M2 and M3 Generation of Horsegram [Macrotyloma uniflorum (Lam.) Verdc

Background: Induction of mutation plays an important role in the breeding programme among modern methods of plant breeding. Genetic variability is prerequisite for crop improvement and through induced mutation it was found to be very effective for creating variability in the quantitative and qualitative characters. Hence, the present study was aimed to induce genetic variability within short time. In the present investigation positive as well as negative impact on quantitative traits were recorded. Methods: The experiment material comprised of seeds of horsegram [Macrotyloma uniflorum (Lam.) Verdc] variety Paiyur 2 which was subjected to ethyl methane sulphonate (02, 0.3, 0.4 and 0.5%), gamma radiation (100, 200, 300 and 400 Gy) and combination treatments. The mutations affecting gross morphological changes in growth and yield characters such as plant habit, flowering, pod morphology, maturity and seed yield were scored as quantitative characters. The micro mutations at population level can be easily detected in the form of increased variations for quantitative traits in the segregation of mutagen treated populations. Micro mutations can alter morpho-physiological characters hence they are of a particular interest to the plant breeders. ANOVA test was performed to determine the significant differences and duncan’s multiple range test (p=0.05) to compare the differences among treatment means. Result: Among the twenty-five treatments studied both the mutagens, gamma radiations and Ethyl Methane Sulphonate proved to be very effective to induce variability in quantitative traits in M2 and M3 generations. The results of Duncan’s multiple range test analysis revealed that the treatment of mutagens in combinations induced more positive effects as compared to that of using alone. The combined treatments were found positive for improvement of primary branches per plant, no. of pods per plant, pod length, no. of seeds/pod and seed yield per plant in M2 and M3 generations whereas the treatment of gamma irradiation imparted its significant role for improvement of plant height, days required for 50% flowering, days to maturity and 1000 seed weight in both M2 and M3 generations whereas the treatment with Ethyl Methane Sulphonate is useful for improving no. of pods per plant and no. of seeds/pod in M2 generation alone.

Diversity of Pod Shape in Pisum

The seed-containing pod is the defining structure of plants in the legume family, yet pods exhibit a wide range of morphological variation. Within a species pod characters are likely to be correlated with reproductive strategy, and within cultivated forms will correspond to aspects of yield determination and/or end use. Here variation in pod size, described as pod length: pod width ratio, has been analyzed in pea germplasm represented by 597 accessions. This pod size variation is discussed with respect to population structure and to known classical pod morphology mutants. Variability of the pod length: width ratio can be explained by allelic variation at two genetic loci that may correspond to organ-specific negative regulators of growth.

Pod Morphology, Primary and Secondary Metabolite Profiles in Non-grafted and Grafted Carob Germplasm Are Configured by Agro-Environmental Zone, Genotype, and Growing Season.

Carob is a predominantly rainfed tree crop of high nutritive value and a long history of adaptation to the edaphoclimatic stress conditions of the Mediterranean. However, declining attention to the carob tree in recent decades has aggravated genetic erosion. The extant in situ germplasm varies both in terms of pod morphology and composition, reflecting the genetic and physiological divide chiefly among grafted and non-grafted material, and possibly the impact of variable agro-environments. Accordingly, the present study aimed to establish a systematic categorization of the genetic and phenotypic diversity encountered across carob germplasm identified in situ throughout Cyprus, a historical center of production and genetic diversity for the species. Linking pod morphology, primary and secondary metabolite profiles with genotyped source material originating in different agro-environments and crop seasons would provide a framework for interpreting (a) the interaction of these factors in configuring carob pod physicochemical constitution, and (b) the relative stability of phenotypic traits against environmental and seasonal variation. Microsatellite analysis discriminated 36 genotypes out of the 124 trees located in nine traditional agro-environmental zones and revealed low genetic diversity within the grafted germplasm. Two landraces were identified: “Tillyria,” which is widespread and predominant, and “Kountourka,” which is mainly localized to the northeastern peninsula of Karpasia. Morphological traits, such as seeds-to-pod weight ratio, pod width and thickness were principally under genetic control. Contrarily, compositional traits, particularly total phenolic content—including condensed tannins, in vitro antioxidant capacity and to a lesser extent gallic acid, organic acids and minerals were under agro-environmental control. Agro-environmental zone also modulated principally fructose and glucose; sucrose was modulated equally by genotype and agro-environment, while total sugars were under genetic control. Statistically significant differences between seasons were detected for all traits except for the seeds-to-pod weight ratio, pod length and width. Hierarchical cluster analysis corroborates that Cyprus may be divided into two major agro-environmental zones modulating the compositional properties of the carob pulp. The present study provides a comprehensive insight into the extant carob genetic resources of Cyprus and advances our understanding of how genetic, agro-environmental and seasonal factors interact in shaping carob pod morphology and composition.

Genetic Structure and Pod Morphology of Inga edulis Cultivated vs. Wild Populations from the Peruvian Amazon

Research Highlights: This study assesses the genetic diversity and structure of the ice-cream-bean (Inga edulis Mart.; Fabaceae) in wild and cultivated populations from the Peruvian Amazon. This research also highlights the importance of protecting the biodiversity of the forest in the Peruvian Amazon, to preserve the genetic resources of species and allow further genetic improvement. Background and Objectives: Ice-cream-bean is one of the most commonly used species in the Amazon region for its fruits and for shading protection of other species (e.g., cocoa and coffee plantations). Comprehensive studies about the impact of domestication on this species’ genetic diversity are needed, to find the best conservation and improvement strategies. Materials and Methods: In the current study, the genetic structure and diversity were assessed by genotyping 259 trees, sampled in five wild and 22 cultivated I. edulis populations in the Peruvian Amazon, with microsatellite markers. Pod length was measured in wild and cultivated trees. Results: The average pod length in cultivated trees was significantly higher than that in wild trees. The expected genetic diversity and the average number of alleles was higher in the wild compared to the cultivated populations; thus, a loss of genetic diversity was confirmed in the cultivated populations. The cultivated trees in the Loreto region had the highest pod length and lowest allelic richness; nevertheless, the wild populations’ genetic structure was not clearly differentiated (significantly different) from that of the cultivated populations. Conclusions: A loss of genetic diversity was confirmed in the cultivated populations. The species could have been simultaneously domesticated in multiple locations, usually from local origin. The original I. edulis Amazonian germplasm should be maintained. Cultivated populations’ new germplasm influx from wild populations should be undertaken to increase genetic diversity.

Use and management of tamarind (Tamarindus indica L., Fabaceae) local morphotypes by communities in Tigray, Northern Ethiopia

ABSTRACTThe population structure, phenotypic differences and ethnobotanical knowledge of tamarind (Tamarindus indica L., Fabaceae) were studied in Kunama- and Tigrigna-speaking communities in the Tigray Regional State of Ethiopia. A vegetation survey on 902 plots of 400 m2 each was conducted along riparian forests and farmlands. Seed and pod morphology of sweet and sour morphotypes was compared based on 6 pods/tree from 20 trees. Thirty-two key informants and 256 randomly selected general informants were interviewed about the use and management of tamarind. Tree densities differed significantly among sociocultural groups and land use. Relatively more trees (6.0–17.5 individuals per hectare) were found in riparian forests as compared to farmland (4.0–7.8). Stem diameter class distribution has a bell-shape, indicating a regeneration problem. Morphological characteristics (pod length, pod width, pod weight, seed weight, pulp weight, and the number of seeds per pod) differed significantly between sour and sweet tamarind morphotypes (p < .05). Interviews identified seven use categories of tamarind, including human and veterinary medicines and five food types, with a greater number of uses mentioned within Kunama communities. Results can be used to support the sustainable use of tamarind in riparian forests and on farms, including conservation of varietal diversity based on the complementary knowledge of both communities.

Functional Genomics and Genetic Control of Flower and Fruit Development in Medicago truncatula: An Overview.

A-, B-, and C-class genes code for MADS-box transcription factors required for floral organ identity in angiosperms. Other members of the family are also crucial to ensure proper carpel and fruit development. Development of genetic and genomic tools for Medicago truncatula has allowed its use as model system to study the genetic control of flower and fruit development in legumes. M. truncatula contains a single A-class gene, four B-function genes, and three C-class genes in its genome. This has made possible to do extensive functional characterization of these MADS-box transcription factors using gene expression analyses, protein-protein interactions, and forward and reverse genetic approaches. We have demonstrated the functions of these MADS-box transcription factors and the respective contributions of paralogous gene pairs to M. truncatula floral development. We have also defined the evolutionary outcomes of each duplicated pairs thus testing theoretical framework of several models about the evolution by gene duplication. Moreover, we have also studied the function of MADS-box fruit genes and how they may have contributed to the diversification of pod morphology within the Medicago genus. Our findings not only have contributed to increase knowledge in the field of the genetic control of flower and fruit development but also have provided a more complete understanding of the complexity of evolution by gene duplication and protein sequence diversification.

Physiological Mechanisms behind Differences in Pod Shattering Resistance in Rapeseed (Brassica napus L.) Varieties.

Pod shattering resistance index (SRI) is a key factor affecting the mechanical harvesting of rapeseed. Research on the differences in pod shattering resistance levels of various rapeseed varieties can provide a theoretical basis for varietal breeding and application in mechanical harvesting. The indicators on pod shattering resistance including pod morphology and wall components were evaluated on eight hybrids and open pollinators, respectively, during 2012–2014. The results showed the following: (1) From the current study, SRI varied greatly with variety, and conventional varieties had stronger resistance than hybrid according to the physiological indexes. and (2) Under the experimental conditions, the SRI was linearly related to pod wall weight and the water content in pod walls, and the goodness-of-fit measurements for the regression model of the SRI based on pod wall weight and water content were 0.584** and 0.377*, respectively, reaching the significant level. This illustrated that pod wall weight and the water content in pod walls determined the SRI. (3) Compared with the relative contents of biochemical components in pod walls, the contents of particular biochemical components in pod walls had closer correlations with SRI. Among the biochemical components, the hemicellulose content was the decisive factor for the SRI.

Regulation of brassinosteroid on pod growth through cell hypertrophy in soybean (Glycine max (L.) Merr.)

Pod size of soybean is an important factor in the determination of seed weight. However, little is known about pod growth of soybean. Brassinosteroid, a group of phytohormones, regulate the pod growth of faba bean. We therefore investigated the role of brassinosteroid in pod growth of soybean. We measured pod length and cell number and cell area in pods treated with a brassinosteroid biosynthesis inhibitor. The inhibitor suppressed pod growth through the reduction of cell area. We then examined pod morphology and the expression of brassinosteroid biosynthesis (GmCYP450 85A1, 2 and 3) and response (GmBZR1, GmBES1 and GmBRU1) genes in the pods of two cultivars that differ in pod size. The difference in pod size was attributable to cell area, and the expression of brassinosteroid biosynthesis and response genes in pods was higher in the cultivar that has large pods. These results suggest that pod size of soybean is regulated through cell hypertrophy caused by brassinosteroid.

Cacao trees (Theobroma cacao L.) of the “Guiana” genetic group: “Tanpok 2012” survey

The wild cacao trees (Theobroma cacao L.) of French Guiana were investigated during several survey and collecting expeditions between 1985 and 1995. The many studies made of this material showed it to be highly original. New surveys were undertaken in May 2012 in south-eastern French Guiana, in the upper reaches of the Tanpok River and some of its tributaries, in order to enrich the cacao collection preserved at the Paracou-Combi site at Sinnamary (French Guiana). One of the aims of the expedition was to determine whether the populations from the upper-Tanpok were original and different from those already represented in the collection. From the 2012 mission four populations were identified. The material collected was described (location, tree and pod morphology). Genetic diversity of the collected genotypes and various controls was studied using SSR markers. The collected trees belonged to the “Guiana” group, but did not reveal any distinctive feature within the group. The genetic diversity encountered was low (He = 0.124). The outcome of these surveys is positive, since new populations were located. In order to preserve and carry out phenotypical studies (agro-morphology) on the new material collected, a plot was planted at Paracou-Combi in January 2013.

Protocols for Obtaining Zygotic and Somatic Embryos for Studying the Regulation of Early Embryo Development in the Model Legume Medicago truncatula.

Early embryogenesis starting from a single cell zygote goes through rapid cell division and morphogenesis, and is morphologically characterized by pre-globular, globular, heart, torpedo and cotyledon stages. This progressive development is under the tight regulation of a complex molecular network. Harvesting sufficient early embryos at a similar stage of development is essential for investigating the cellular and molecular regulation of early embryogenesis. This is not straightforward since early embryogenesis undergoes rapid morphogenesis in a short while e.g. 8 days for Medicago truncatula to reach the early cotyledon stage. Here, we address the issue by two approaches. The first one establishes a linkage between embryo development and pod morphology in helping indicate the stage of the zygotic embryo. This is particularly based on the number of pod spirals and development of the spines. An alternative way to complement the in vivo studies is via culturing leaf explants to produce somatic embryos. The medium includes an unusual hormone combination - an auxin (1-naphthaleneacetic acid), a cytokinin (6-benzylaminopurine), abscisic acid and gibberellic acid. The different stages can be discerned growing out of the callus without dissection.

Structure and evolution of the pod inIndigofera(Fabaceae) reveals a trend towards small thin indehiscent pods

Pod morphology and anatomy have been studied in 28 species and four varieties of Indian Indigofera. Pods of Indigofera spp. differ with respect to size, the relative thickness of the fruit wall, the number of sclerenchymatous layers in the endocarp, the presence/absence of hypodermis and trichomes, and the presence of separation tissue. Anatomically, the pericarp is broadly characterized into three types: type I (thin pericarp and three to five sclerenchymatous layers in the endocarp), type II (intermediary pericarp thickness and six to eight sclerenchymatous layers), and type III (thick pericarp and more than eight sclerenchymatous layers). The distribution of these types across the tribe is not congruent with the current phylogenetic analyses. Type III pericarp (present in the early diverging lineages of the tribe) represents the most primitive state, whereas type I and type II pericarps are derived. Fruits of Indigofera generally show normal explosive dehiscence as a means of dispersal of seeds, although some species show adaptations for dispersal by wind. In Indigofera, dehiscence is caused by a separation layer present at the dorsal and ventral sutures except in some species (Indigofera hochstetteri, Indigofera karnatakana, Indigofera glandulosa var. sykesii, and Indigofera trita var. scabra) in which no separation tissue is present; these species show delayed dehiscence or an indehiscent condition. The indehiscent pod type is considered to be apomorphic. The taxonomic, functional, and evolutionary significance of morphological and anatomical features in fruits of the genus Indigofera has been evaluated. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176, 260–276.