A dated molecular phylogeny and biogeographical analysis reveals the evolutionary history of the trans-pacifically disjunct tropical tree genus Ormosia (Fabaceae).

The papilionoid legume genus Ormosia (Fabaceae) comprises about 150 species of trees and exhibits a striking disjunct geographical distribution between the New World- and Asian and Australasian wet tropics and subtropics. Modern classifications of Ormosia are not grounded on a well-substantiated phylogenetic hypothesis and have been limited to just portions of the geographical range of the genus. The lack of an evolutionarily-based foundation for systematic studies has hindered taxonomic work on the genus and prevented the testing of biogeographical hypotheses related to the origin of the Old World/New World disjunction and the individual dispersal histories within both areas. Here, we present the most comprehensively sampled molecular phylogeny of Ormosia to date, based on analysis of both nuclear (ITS) and plastid (matK and trnL-F) DNA sequences from 82 species of the genus. Phylogenetically-based divergence times and ancestral range estimations are employed to test hypotheses related to the biogeographical history of the genus. We find strong support for the monophyly of Ormosia and the grouping of all sampled Asian species of the genus into two comparably sized clades, one of which is sister to another large clade containing all sampled New World species. Within the New World clade, additional resolution supports the grouping of most species into three mutually exclusive subordinate clades. The remaining New World species form a fourth well-supported clade in the analyses of plastid sequences, but that result is contradicted by the analysis of ITS. With few exceptions the supported clades have not been previously recognized as taxonomic groups. The biogeographical analysis suggests that Ormosia originated in continental Asia and dispersed to the New World in the Oligocene or early Miocene via long-distance trans-oceanic dispersal. We reject the hypothesis that the inter-hemispheric disjunction in Ormosia resulted from fragmentation of a more continuous "Boreotropical" distribution since the dispersal post-dates Eocene climatic maxima. Both of the Old World clades appear to have originated in mainland Asia and subsequently dispersed into the Malay Archipelago and beyond, at least two lineages dispersing across Wallace's Line as far as the Solomon Islands and northeastern Australia. In the New World, the major clades all originated in Amazonia. Dispersal from Amazonia into peripheral areas in Central America, the Caribbean, and Extra-Amazonian Brazil occurred multiple times over varying time scales, the earliest beginning in the late Miocene. In a few cases, these dispersals were followed by local diversification, but not by reverse migration back to Amazonia. Within each of the two main areas of distribution, multiple modest bouts of oceanic dispersal were required to achieve the modern distributions.

Fossil papilionoids of the Bowdichia clade (Leguminosae) from the Paleogene of North America.

PREMISE: Understanding the evolutionary history of flowering plants has been enriched by the integration of molecular phylogenies and evidence from the fossil record. Fossil fruits and leaves from the late Paleocene and Eocene of Wyoming and Eocene of Kentucky and Tennessee are described as extinct genera in the tropical American Bowdichia clade of the legume subfamily Papilionoideae. Recent phylogenetic study and taxonomic revision of the Bowdichia clade have facilitated understanding of relationships of the fossil taxa and their evolutionary implications and paleoenvironmental significance. METHODS: The fossils were studied using standard methods of specimen preparation and light microscopy and compared to fruits and leaves from extant legume taxa using herbarium collections. Phylogenetic relationships of the fossil taxa were assessed using morphology and DNA sequence data. RESULTS: Two new fossil genera are described and their phylogenetic relationships are established. Paleobowdichia lamarensis is placed as sister to the extant genus Bowdichia and Tobya claibornensis is placed with the extant genera Guianodendron and Staminodianthus. CONCLUSIONS: These fossils demonstrate that the tropical American Bowdichia clade was present in North America during a period when tropical or subtropical conditions prevailed in the northern Rocky Mountains during the late Paleocene and the Mississippi Embayment during the middle Eocene. These fossils also document that the Bowdichia clade had diversified by the late Paleocene when the fossil record of the family is relatively sparse. This result suggests that future work on early fossil legumes should focus on tropical and subtropical climatic zones, wherever they may occur latitudinally.

Micro- and macroevolutionary adaptation through repeated loss of a complete metabolic pathway.

There is growing evidence for the convergent evolution of physically linked gene clusters encoding chemical defense pathways. Metabolic clusters are proposed to evolve because they ensure co-inheritance of all required genes where the defense is favored, and prevent inheritance of toxic partial pathways where it is not. This hypothesis rests on the assumption that clusters evolve in species where selection favors intraspecific polymorphism for the defense; however, they have not been examined in polymorphic species. We examined metabolic cluster evolution in relation to an adaptive polymorphism for cyanogenic glucoside (CNglc) production in clover. Using 163 accessions, we performed CNglc assays, BAC sequencing, Southern hybridizations and molecular evolutionary analyses. We find that the CNglc pathway forms a 138-kb cluster in white clover, and that the adaptive polymorphism occurs through presence/absence of the complete cluster. Component genes are orthologous to those in the distantly related legume Lotus japonicus. These findings provide empirical support for the co-inheritance hypothesis, and they indicate that adaptive CNglc variation in white clover evolves through recurrent deletions of the entire pathway. They further indicate that the shared ancestor of many important legume crops was likely cyanogenic and that this defense was lost repeatedly over the last 50 Myr.

A molecular phylogeny reveals the Cuban enigmatic genus Behaimia as a new piece in the Brongniartieae puzzle of papilionoid legumes.

The papilionoid legume tribe Brongniartieae comprises a collection of 15 genera with disparate morphologies that were previously positioned in at least four remotely related tribes. The Brongniartieae displays a wide geographical disjunction between Australia and the New World and previous phylogenetic studies had provided conflicting results about the relationships between the American and Australian genera. We carry out phylogenetic analyses of (1) a plastid matK dataset extensively sampled across legumes to solve the enigmatic relationship of the Cuban-endemic monospecific genus Behaimia; and (2) multilocus datasets with focus on all genera ever referred to Brongniartieae. These analyses resulted in a well-resolved and strongly-supported phylogenetic tree of the Brongniartieae. The monophyly of all American genera of Brongniartieae is strongly supported. The doubtful position of the Australian genus Plagiocarpus is resolved within a clade comprising all Australian genera. Behaimia has been traditionally classified in tribe Millettieae, but our new molecular data and re-assessment of morphological traits have resolved the genus within the early-branching papilionoid tribe Brongniartieae. Characters including the pinnately multifoliolate (vs. unifoliolate) leaves, a sessile (vs. stipitate) ovary, and an indehiscent or late dehiscent one-seeded pod distinguish Behaimia from its closer relatives, the South American genera Cyclolobium and Limadendron.

A molecular-dated phylogeny and biogeography of the monotypic legume genus Haplormosia, a missing African branch of the otherwise American-Australian Brongniartieae clade.

A comprehensively sampled reassessment of the molecular phylogeny of the genistoid legumes questions the traditional placement of Haplormosia, an African monotypic genus traditionally classified within tribe Sophoreae close to the Asian-American geographically disjunct genus Ormosia. Plastid matK sequences placed Haplormosia as sister to the American-Australian tribe Brongniartieae. Despite a superficial resemblance between Haplormosia and Ormosia, a re-examination of the morphology of Haplormosia corroborates the new phylogenetic result. The reciprocally monophyletic deep divergence of the Haplormosia stem lineage from the remaining Brongniartieae is dated to ca. 52Mya, thus supporting a signature of an old single long-distance dispersal during the early Eocene. Conversely, we estimated a relatively recent long-distance dispersal rooted in the Early Miocene for the Australian Brongniartieae clade emerging from within a grade of American Brongniartieae. The Bayesian ancestral area reconstruction revealed the coming and going of neotropical ancestors during the diversification history of the Brongniartieae legumes in Africa and all over the Americas and Australia.

Multiple polyploidy events in the early radiation of nodulating and nonnodulating legumes.

Unresolved questions about evolution of the large and diverse legume family include the timing of polyploidy (whole-genome duplication; WGDs) relative to the origin of the major lineages within the Fabaceae and to the origin of symbiotic nitrogen fixation. Previous work has established that a WGD affects most lineages in the Papilionoideae and occurred sometime after the divergence of the papilionoid and mimosoid clades, but the exact timing has been unknown. The history of WGD has also not been established for legume lineages outside the Papilionoideae. We investigated the presence and timing of WGDs in the legumes by querying thousands of phylogenetic trees constructed from transcriptome and genome data from 20 diverse legumes and 17 outgroup species. The timing of duplications in the gene trees indicates that the papilionoid WGD occurred in the common ancestor of all papilionoids. The earliest diverging lineages of the Papilionoideae include both nodulating taxa, such as the genistoids (e.g., lupin), dalbergioids (e.g., peanut), phaseoloids (e.g., beans), and galegoids (=Hologalegina, e.g., clovers), and clades with nonnodulating taxa including Xanthocercis and Cladrastis (evaluated in this study). We also found evidence for several independent WGDs near the base of other major legume lineages, including the Mimosoideae-Cassiinae-Caesalpinieae (MCC), Detarieae, and Cercideae clades. Nodulation is found in the MCC and papilionoid clades, both of which experienced ancestral WGDs. However, there are numerous nonnodulating lineages in both clades, making it unclear whether the phylogenetic distribution of nodulation is due to independent gains or a single origin followed by multiple losses.

Molecular systematics of the Amazonian genus Aldina, a phylogenetically enigmatic ectomycorrhizal lineage of papilionoid legumes.

Aldina (Leguminosae) is among the very few ecologically successful ectomycorrhizal lineages in a family largely marked by the evolution of nodulating symbiosis. The genus comprises 20 species predominantly distributed in Amazonia and has been traditionally classified in the tribe Swartzieae because of its radial flowers with an entire calyx and numerous free stamens. The taxonomy of Aldina is complicated due to its poor representation in herbaria and the lack of a robust phylogenetic hypothesis of relationship. Recent phylogenetic analyses of matK and trnL sequences confirmed the placement of Aldina in the 50-kb inversion clade, although the genus remained phylogenetically isolated or unresolved in the context of the evolutionary history of the main early-branching papilionoid lineages. We performed maximum likelihood and Bayesian analyses of combined chloroplast datasets (matK, rbcL, and trnL) and explored the effect of incomplete taxa or missing data in order to shed light on the enigmatic phylogenetic position of Aldina. Unexpectedly, a sister relationship of Aldina with the Andira clade (Andira and Hymenolobium) is revealed. We suggest that a new tribal phylogenetic classification of the papilionoid legumes should place Aldina along with Andira and Hymenolobium. These results highlight yet another example of the independent evolution of radial floral symmetry within the early-branching Papilionoideae, a large collection of florally heterogeneous lineages dominated by papilionate or bilaterally symmetric flower morphology.

A multilocus phylogenetic analysis reveals the monophyly of a recircumscribed papilionoid legume tribe Diocleae with well-supported generic relationships.

Deciphering the phylogenetic relationships within the species-rich Millettioid clade has persisted as one of the major challenges in the systematics and evolutionary history of papilionoid legumes (Leguminosae, Papilionoideae). Historically, the predominantly neotropical lianas of subtribe Diocleinae in the Millettioid legumes have been taxonomically tangled together with the largely heterogeneous tribe Phaseoleae. This work presents a comprehensive molecular phylogenetic analysis based on nuclear and chloroplast markers and includes all genera ever referred to Diocleae except for the monospecific Philippine Luzonia, resolving several key generic relationships within the Millettioid legumes. The first of two separate analyses includes 310 matK accessions and strongly supports the reestablishment of tribe Diocleae as a branch of the Millettioid clade. This work sheds greater light on the higher-level phylogeny of Diocleae and allows the recognition of three major lineages: the Canavalia, Dioclea, and Galactia clades. The second set of phylogenetic analyses utilized nuclear (ITS/5.8S and ETS) and plastid (matK and trnT-Y) DNA sequences to reveal (i) the monophyly of Canavalia and Cleobulia; (ii) the monophyly of Bionia with the exclusion of Bionia bella; (iii) the paraphyly of Dioclea with respect to Cleobulia, Cymbosema, and Macropsychanthus; (iv) the paraphyly of Cratylia with respect to the broadly polyphyletic Camptosema; and (v) the polyphyly of Galactia with species scattered widely across the tree.

Filling in the gaps of the papilionoid legume phylogeny: the enigmatic Amazonian genus Petaladenium is a new branch of the early-diverging Amburaneae clade.

Recent deep-level phylogenies of the basal papilionoid legumes (Leguminosae, Papilionoideae) have resolved many clades, yet left the phylogenetic placement of several genera unassessed. The phylogenetically enigmatic Amazonian monospecific genus Petaladenium had been believed to be close to the genera of the Genistoid Ormosieae clade. In this paper we provide the first DNA phylogenetic study of Petaladenium and show it is not part of the large Genistoid clade, but is a new branch of the Amburaneae clade, one of the first-diverging lineages of the Papilionoideae phylogeny. This result is supported by the chemical observation that the quinolizidine alkaloids, a chemical synapomorphy of the Genistoids, are absent in Petaladenium. Parsimony and Bayesian phylogenetic analysis of nuclear ITS/5.8S and plastid matK and trnL intron agree with a new interpretation of morphology that Petaladenium is sister to Dussia, a genus comprising ∼18 species of trees largely confined to rainforests in Central America and northern South America. Petaladenium, Dussia, and Myrospermum have papilionate flowers in a clade otherwise with radial floral symmetry, loss of petals or incompletely differentiated petals. Our phylogenetic analyses also revealed well-supported resolution within the three main lineages of the ADA clade (Angylocalyceae, Dipterygeae, and Amburaneae). We also discuss further molecular phylogenetic evidence for the undersampled Amazonian genera Aldina and Monopteryx, and the tropical African Amphimas, Cordyla, Leucomphalos, and Mildbraediodendron.

Flowers of the early-branching papilionoid legume Petaladenium urceoliferum display unique morphological and ontogenetic features.

PREMISE OF THE STUDY: Floral development can help to shed light on puzzling features across flowering plants. The enigmatic Amazonian monospecific genus Petaladenium of the legume family (Leguminosae) had rarely been collected and only recently became available for ontogenetic studies. The fimbriate-glandular wing petals of P. urceoliferum are unique among the more than 19000 legume species. Ontogenetic data illuminate the systematic position of the genus and foster our understanding on floral evolution during the early diversification of the papilionoid legumes. METHODS: Flower buds were collected in the field, fixed in 70% ethanol, and investigated using scanning electron microscopy (SEM). Results were compared with existing material from early-diverging papilionoid legumes. KEY RESULTS: Formation of sepals and petals shows bidirectional tendencies. Stamens arise in two whorls, and the single carpel arises concomitantly with the outer stamen whorl. Gland formation starts early on the edges of the wing petals. The carpel reopens for a short time when the initiation of ovules is visible. Stomata at the base of the hypanthium indicate that the flower functions like other standard flag blossoms. CONCLUSIONS: The floral ontogeny confirms the close affinity of P. urceoliferum with the florally heterogeneous, early-diverging papilionoid Amburaneae clade. The results strengthen the theory of a distinct experimental phase among early-branching papilionoid legumes during which a wider range of floral morphologies arose. Polysymmetry, monosymmetry, variable organ numbers, and a wide range of ontogenetic patterns laid the foundation for a successful canalization toward the more restricted but well-adapted dorsiventral papilionoid flag blossom.

Molecular and ultrastructural analysis of forisome subunits reveals the principles of forisome assembly.

BACKGROUND AND AIMS: Forisomes are specialized structural phloem proteins that mediate sieve element occlusion after wounding exclusively in papilionoid legumes, but most studies of forisome structure and function have focused on the Old World clade rather than the early lineages. A comprehensive phylogenetic, molecular, structural and functional analysis of forisomes from species covering a broad spectrum of the papilionoid legumes was therefore carried out, including the first analysis of Dipteryx panamensis forisomes, representing the earliest branch of the Papilionoideae lineage. The aim was to study the molecular, structural and functional conservation among forisomes from different tribes and to establish the roles of individual forisome subunits. METHODS: Sequence analysis and bioinformatics were combined with structural and functional analysis of native forisomes and artificial forisome-like protein bodies, the latter produced by expressing forisome genes from different legumes in a heterologous background. The structure of these bodies was analysed using a combination of confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the function of individual subunits was examined by combinatorial expression, micromanipulation and light microscopy. KEY RESULTS: Dipteryx panamensis native forisomes and homomeric protein bodies assembled from the single sieve element occlusion by forisome (SEO-F) subunit identified in this species were structurally and functionally similar to forisomes from the Old World clade. In contrast, homomeric protein bodies assembled from individual SEO-F subunits from Old World species yielded artificial forisomes differing in proportion to their native counterparts, suggesting that multiple SEO-F proteins are required for forisome assembly in these plants. Structural differences between Medicago truncatula native forisomes, homomeric protein bodies and heteromeric bodies containing all possible subunit combinations suggested that combinations of SEO-F proteins may fine-tune the geometric proportions and reactivity of forisomes. CONCLUSIONS: It is concluded that forisome structure and function have been strongly conserved during evolution and that species-dependent subsets of SEO-F proteins may have evolved to fine-tune the structure of native forisomes.

The genomes of 5 underutilized Papilionoideae crops provide insights into root nodulation and disease resistance.

BACKGROUND: The Papilionoideae subfamily contains a large amount of underutilized legume crops, which are important for food security and human sustainability. However, the lack of genomic resources has hindered the breeding and utilization of these crops. RESULTS: Here, we present chromosome-level reference genomes for 5 underutilized diploid Papilionoideae crops: sword bean (Canavalia gladiata), scarlet runner bean (Phaseolus coccineus), winged bean (Psophocarpus tetragonolobus), smooth rattlebox (Crotalaria pallida), and butterfly pea (Clitoria ternatea), with assembled genome sizes of 0.62 Gb, 0.59 Gb, 0.71 Gb, 1.22 Gb, and 1.72 Gb, respectively. We found that the long period of higher long terminal repeat retrotransposon activity is the major reason that the genome size of smooth rattlebox and butterfly pea is enlarged. Additionally, there have been no recent whole-genome duplication (WGD) events in these 5 species except for the shared papilionoid-specific WGD event (∼55 million years ago). Then, we identified 5,328 and 10,434 species-specific genes between scarlet runner bean and common bean, respectively, which may be responsible for their phenotypic and functional differences and species-specific functions. Furthermore, we identified the key genes involved in root-nodule symbiosis (RNS) in all 5 species and found that the NIN gene was duplicated in the early Papilionoideae ancestor, followed by the loss of 1 gene copy in smooth rattlebox and butterfly pea lineages. Last, we identified the resistance (R) genes for plant defenses in these 5 species and characterized their evolutionary history. CONCLUSIONS: In summary, this study provides chromosome-scale reference genomes for 3 grain and vegetable beans (sword bean, scarlet runner bean, winged bean), along with genomes for a green manure crop (smooth rattlebox) and a food dyeing crop (butterfly pea). These genomes are crucial for studying phylogenetic history, unraveling nitrogen-fixing RNS evolution, and advancing plant defense research.

Papilionoid inflorescences revisited (Leguminosae-Papilionoideae).

BACKGROUND AND AIMS: The inflorescence structure determines the spatiotemporal arrangement of the flowers during anthesis and is therefore vital for reproductive success. The Leguminosae are among the largest angiosperm plant families and they include some important crop plants. In papilionoid legumes, the raceme is the most common type of inflorescence. However, a range of other inflorescence types have evolved via various developmental processes. A (re-)investigation of inflorescences in Swainsona formosa, Cicer arietinum, Abrus precatorius, Hardenbergia violacea and Kennedia nigricans leads to new insights into reduction mechanisms and to a new hypothesis on the evolution of the papilionoid pseudoraceme. METHODS: Inflorescence morphology and ontogeny were studied using scanning electron microscopy (SEM). KEY RESULTS: The inflorescence in S. formosa is an umbel with a rare type of pendulum symmetry which may be triggered by the subtending leaf. Inflorescences in C. arietinum are reduced to a single flower. An early formed adaxial bulge is the sterile apex of the inflorescence (i.e. the inflorescence is open and not terminated by a flower). In partial inflorescences of A. precatorius, the axis is reduced and its meristem is relocated towards the main inflorescence. Flower initiation follows a peculiar pendulum pattern. Partial inflorescences in H. violacea and in K. nigricans show reduction tendencies. In both taxa, initiated but early reduced bracteoles are present. CONCLUSIONS: Pendulum symmetry in S. formosa is probably associated with distichous phyllotaxis. In C. arietinum, strong reduction tendencies are revealed. Based on studies of A. precatorius, the papilionoid pseudoraceme is reinterpreted as a compound raceme with condensed lateral axes. From an Abrus-like inflorescence, other types can be derived via reduction of flower number and synchronization of flower development. A plea is made for uniform usage of inflorescence terminology.

Phylogenomics and plastome evolution of Indigofera (Fabaceae).

Introduction: Indigofera L. is the third largest genus in Fabaceae and includes economically important species that are used for indigo dye-producing, medicinal, ornamental, and soil and water conservation. The genus is taxonomically difficult due to the high level of overlap in morphological characters of interspecies, fewer reliability states for classification, and extensive adaptive evolution. Previous characteristic-based taxonomy and nuclear ITS-based phylogenies have contributed to our understanding of Indigofera taxonomy and evolution. However, the lack of chloroplast genomic resources limits our comprehensive understanding of the phylogenetic relationships and evolutionary processes of Indigofera. Methods: Here, we newly assembled 18 chloroplast genomes of Indigofera. We performed a series of analyses of genome structure, nucleotide diversity, phylogenetic analysis, species pairwise Ka/Ks ratios, and positive selection analysis by combining with allied species in Papilionoideae. Results and discussion: The chloroplast genomes of Indigofera exhibited highly conserved structures and ranged in size from 157,918 to 160,040 bp, containing 83 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Thirteen highly variable regions were identified, of which trnK-rbcL, ndhF-trnL, and ycf1 were considered as candidate DNA barcodes for species identification of Indigofera. Phylogenetic analysis using maximum likelihood (ML) and Bayesian inference (BI) methods based on complete chloroplast genome and protein-coding genes (PCGs) generated a well-resolved phylogeny of Indigofera and allied species. Indigofera monophyly was strongly supported, and four monophyletic lineages (i.e., the Pantropical, East Asian, Tethyan, and Palaeotropical clades) were resolved within the genus. The species pairwise Ka/Ks ratios showed values lower than 1, and 13 genes with significant posterior probabilities for codon sites were identified in the positive selection analysis using the branch-site model, eight of which were associated with photosynthesis. Positive selection of accD suggested that Indigofera species have experienced adaptive evolution to selection pressures imposed by their herbivores and pathogens. Our study provided insight into the structural variation of chloroplast genomes, phylogenetic relationships, and adaptive evolution in Indigofera. These results will facilitate future studies on species identification, interspecific and intraspecific delimitation, adaptive evolution, and the phylogenetic relationships of the genus Indigofera.

Highly Resolved Papilionoid Legume Phylogeny Based on Plastid Phylogenomics.

Comprising 501 genera and around 14,000 species, Papilionoideae is not only the largest subfamily of Fabaceae (Leguminosae; legumes), but also one of the most extraordinarily diverse clades among angiosperms. Papilionoids are a major source of food and forage, are ecologically successful in all major biomes, and display dramatic variation in both floral architecture and plastid genome (plastome) structure. Plastid DNA-based phylogenetic analyses have greatly improved our understanding of relationships among the major groups of Papilionoideae, yet the backbone of the subfamily phylogeny remains unresolved. In this study, we sequenced and assembled 39 new plastomes that are covering key genera representing the morphological diversity in the subfamily. From 244 total taxa, we produced eight datasets for maximum likelihood (ML) analyses based on entire plastomes and/or concatenated sequences of 77 protein-coding sequences (CDS) and two datasets for multispecies coalescent (MSC) analyses based on individual gene trees. We additionally produced a combined nucleotide dataset comprising CDS plus matK gene sequences only, in which most papilionoid genera were sampled. A ML tree based on the entire plastome maximally supported all of the deep and most recent divergences of papilionoids (223 out of 236 nodes). The Swartzieae, ADA (Angylocalyceae, Dipterygeae, and Amburaneae), Cladrastis, Andira, and Exostyleae clades formed a grade to the remainder of the Papilionoideae, concordant with nine ML and two MSC trees. Phylogenetic relationships among the remaining five papilionoid lineages (Vataireoid, Dermatophyllum, Genistoid s.l., Dalbergioid s.l., and Baphieae + Non-Protein Amino Acid Accumulating or NPAAA clade) remained uncertain, because of insufficient support and/or conflicting relationships among trees. Our study fully resolved most of the deep nodes of Papilionoideae, however, some relationships require further exploration. More genome-scale data and rigorous analyses are needed to disentangle phylogenetic relationships among the five remaining lineages.

Erratum: Highly Resolved Papilionoid Legume Phylogeny Based on Plastid Phylogenomics.

[This corrects the article DOI: 10.3389/fpls.2022.823190.].

The complete chloroplast genome of the threatened Napa False Indigo Amorpha californica var. napensis Jeps. 1925 (Fabaceae) from Northern California, USA.

Amorpha californica var. napensis Jeps. 1925, the Napa false indigo, is a threatened shrub endemic to northern California. Here the complete chloroplast genome of topotype material of var. napensis was assembled and characterized to contribute to the bioinformatics, systematics, and conservation of this variety. The chloroplast genome (GenBank accession OK274088) is 158,294 base pairs (bp) in length, encodes 130 genes including 85 protein-coding, 37 tRNA, 8 rRNA, and shows a high-level of gene synteny to other Papilionoideae. Phylogenetic analysis fully resolved var. napensis in a clade with A. fruticosa L. and A. roemeriana Scheele, sister to the Dalbergieae. The newly sequenced chloroplast genome shows that the genetic differences between var. napensis and Amorpha californica Nutt. var. californica are greater than the variation observed between var. napensis and many other Amorpha spp. sequences deposited in GenBank. These data suggest that var. napensis should be elevated to full species rank.

Implication of scanning electron microscopy in the seed morphology with special reference to three subfamilies of Fabaceae.

The current research work was aimed to determine the morphological variation in the seeds of subfamilies Caesalpinioideae, Mimosoideae, and Papilionoideae using scanning electron microscope to investigate the different seed features including; Seed length, width, weight, hilum shape, position, fracture line pattern, pleurogram shape, texture crudeness, ornamentation wall, and surface ornamentation. A total of 12 species were collected. The study reveals that the seed types alters from psilate to rugose, pleurogram shape from lunar to U shape, hilum shape from elliptical to depressed, hilum position from terminal to subterminal, fracture line pattern from reticulate irregular ridges to psilate with regular ridges, texture crudeness from fine to coarse, surface ornamentation from reticulate to psilate, and ornamentation wall also varies from thin to thick. In all the studied species, it was found that seed surface was brown in color except in Senna alata, in which seed surface was black. Regarding the seed size, it was found that the smallest seed was observed for Sesbania sesban, while the largest seed was observed for Pongamia pinnata. The present research article indicates the taxonomic significance of seed morphology in the subfamilies Caesalpinioideae, Mimosaceae, and Papilionoideae.

Anthyllis apennina (Fabaceae), a new species from central Apennine (Italy).

A new species of Anthyllis endemic to central Apennine growing in dry pastures on limestone in the montane belt, within Abruzzo and Lazio administrative regions (central Italy), is here described and illustrated and the IUCN assessment is proposed. This new species belongs to the morphologically very variable Anthyllis vulneraria species complex and it is close to A. pulchella (south-eastern Europe and Caucasus), but it can be clearly distinguished by its smaller flowers, mainly light yellow-coloured, bracts longer than flowers, calyx pink-coloured (usually only at apex) and size of cauline leaves and leaflets. Furthermore, the name A. pulchella is here lectotypified, by a second-step typification, on a specimen preserved at PAD.

Pygidiapion De Sousa amp; Mermudes, a new genus of Apioninae (Brentidae: Apioninae: Apionini) associated with Fabaceae from Brazil, with the description of a new species and transfer of Apion zikani Heller, 1922.

The genus Pygidiapion De Sousa Mermudes gen. n., described and illustrated here, includes two species from Brazil: the type-species Pygidiapion zeppelinii De Sousa Mermudes sp. n. (type-locality: João Pessoa, Paraiba state), which develops in flower buds of Pterocarpus violaceus Vogel (Fabaceae); and Pygidiapion zikani (Heller, 1922) comb. n. (from Apion) (type-locality: Passa Quatro, Minas Gerais state), which develops in flower buds of Dalbergia foliolosa Benth. (Fabaceae). Pygidiapion is defined by the following set of characters: rostrum of males with two elongate longitudinal and punctate latero-ventral sulci; hind wings with small radial window; hypomeral lobes divided by median suture and sternellum distinctly exposed; meso- and metatibiae mucronate; pygidium of the apionine incomplete type; and tegminal plate fused with basal piece. Pygidiapion zeppelinii is diagnosed by: meso- and metatibiae mucronate; pygidium distinctly modified, with deep transverse dorsal sulcus, medially deeper and rounded, and proximal marginal rim angulate (apical flange), corresponding to the distal margin, which is emarginate; tegminal plate fused to basal piece, apical portion of parameroid lobes weakly notched medially, each side of suprafenestral plate with five macrochaetae, fenestral width 1.25 times length, separated by about 3.2 times fenestral width, linea arquata visible, prostegium protruding medially, tegminal apodeme 0.76 as long as basal piece, with apex narrow and rounded. Pygidiapion zikani is distinguished from P. zeppelinii by smaller size; head, rostrum and antennae brownish; scutellum subquadrate; and by association with Dalbergia spp. (Fabaceae). Association principally with the papilionoid group of Fabaceae suggest allocation of the new taxon to the subtribe Oxystomatina.