Basal Branches Research Articles

Aesthete Pattern Diversity in Chiton Clades (Mollusca: Polyplacophora): Balancing Sensory Structures and Strength in Valve Architecture.

Chitons possess the most elaborate system of shell pores found in any hard-shelled invertebrate. Although chitons possess some anteriorly located sense organs, they lack true cephalization, as their major sensory systems are not concentrated in a distinct head region. Instead, the aesthete system within their shells forms a dense sensory network that overcomes the barrier of their hard dorsal armour. The basic arrangement of neural structures embedded within a solid, opaque matrix, has confounded understanding of the overall network. In this study, we use synchrotron X-ray μCT to visualise the aesthete canal networks inside chiton valves. We selected representatives from all three major chiton clades: Lepidopleurida, the basal branching clade, and Callochitonida and Chitonida, which both havemore complex shell morphology, to compare internal structure. Lepidopleurida aesthete canals are oriented vertically and pass directly through the shell to connect with the body. By contrast, aesthetes canals in Callochitonida and Chitonida have complex internal structures with extended horizontal passages, coalescing at the shell diagonal that corresponds to the valve insertion slits. This represents a stepwise evolution of chiton shell form, where thicker and more complex valves require a diverting and rewiring of the entire sensorynetwork. Aspects of the aesthete system, such as the microscopic arrangement of surface pores, have long been used in chiton taxonomy for species diagnoses; insertion slits should also be understood as a secondary feature of the aesthete system. Chiton shell structures that are used for morphological systematics are driven by sensory adaptations.

Infected nursery stock and poor silvicultural practices contribute to development of Ceratocystis manginecans wilt and canker disease in Eucalyptus pellita

In Indonesia and Malaysia, Eucalyptus pellita has replaced large areas of Acacia mangium plantations as the latter species is highly susceptible to C. manginecans. This strategy may not be effective in the long term as E. pellita is also susceptible to Ceratocystis wilt and canker disease though it has higher tolerance than A. mangium. Furthermore, the pathogen has the capacity to evolve and adapt to new hosts. To highlight the need for careful sanitation in nurseries and the potential impact of wounding during silvicultural operations, two experiments were conducted to (i) demonstrate the ability of cryptic Ceratocystis infections in nursery plants to develop into Ceratocystis wilt and canker disease after planting out and (ii) assess the risk of Ceratocystis infection and disease development from different wound types. In the nursery, three-month-old mini-cuttings of seven E. pellita clones were artificially wounded and inoculated with two isolates of Ceratocystis manginecans near the base of the stem. The disease incidence and lesion length were measured one month later, just prior to planting out. After four months of growth in the plantation, the trees were harvested and stems sliced longitudinally to measure the length of xylem discolouration. Six of 36 ramets of susceptible clones died and the length of xylem discolouration was significantly greater in susceptible clones than in tolerant clones. The second experiment was based on inoculation of 12-month-old plantation-grown trees of one clone of E. pellita with one isolate of C. manginecans using six different wounding methods. The inoculated wounds on the trees all produced xylem discolouration, except for those that only penetrated the outer bark. Disease incidence was greater at stem heights of 30 to 90 cm than on the basal stem or branch stub. The experiment emphasised the importance of minimising the risk of C. manginecans infection following wounding in the nursery and in the field as the discolouration is an indication of xylem blockage that can lead to tree mortality.

Exploring Genetic Variability and Morpho-Agronomic Trait Associations Among Ethiopian Flax (Linum Usitatissimum L.) Accessions for Enhanced Fiber and Seed Yield

ABSTRACT Flax is a versatile crop grown for its fiber and seed oil. Despite extensive conservation efforts in Ethiopia, the genetic potential of flax accessions conserved in the gene bank remains largely underexplored for fiber and seed yield. Here, we aimed to assess the genetic variability and association of morpho-agronomic traits and identify potential accessions for fiber and seed yield among 150 flax accessions. The study was conducted at Holeta Agricultural Research Center during 2022/23 growing season using an augmented design. Data were collected on flowering and maturity dates, plant and technical height, basal and secondary branch, boll and seed numbers, 1000-seed weight, and yield. Results revealed significant variation both between blocks and within treatments, with flowering time, maturity, plant height, boll number, seed weight, and yield contributing for the highest variability (58.7%). Cluster analysis revealed nine distinct genetic groups, each exhibiting specific trait patterns. Seed yield had strong associations with maturity, plant height, and boll number. High broad-sense heritability for days to flowering, plant height, and yield traits suggests selection could be effective based on phenotypic expressions. The study highlights the potential of Ethiopian flax genetic diversity for enhancing fiber and seed yield, suggesting effective selection based on key traits.

New discoveries for the genus Miconia (Melastomataceae): a new species for the brazilian Atlantic Forest

We describe Miconia leonorae, a new species exclusive to eastern Brazil, mainly from the evergreen forests of the Atlantic Forest Domain. This species can be distinguished from a wider circumscription of Miconia lepidota. It is classified as Miconia supersect. Discolores sect. Multispicatae and can be distinguished from similar species by features such as an acute leaf base and apex, light brown to gray abaxial leaf blade indumentum with lepidote-stellate trichomes (becoming glabrescent on mature leaves), cylindrical, scorpioid inflorescences with basal branches only bifid or trifid, and an androecium with isomorphic stamens.

Contrary to phylogenetic predictions, crown coloration of the Eared Dove is not regulated by sex hormones

The mechanisms regulating plumage coloration appear to be phylogenetically conserved in avian species: the plesiomorphic character state is estrogen-dependent regulation, while testosterone, luteinizing hormone, and non-hormonal control are derived states. Limited data exist on the underlying regulatory processes of sexual dichromatism in the Eared Dove ( Zenaida auriculata (Des Murs, 1847)). Since the Columbiformes order is close to basal branches, we hypothesized that estrogen and testosterone play a central role in the regulation of crown plumage coloration in the Eared Dove. To test this, we subjected adult males to a forced molt accompanied by an exogenous increase of estradiol and testosterone to determine whether the presence of these hormones during molting modified the spectrophotometric characteristics of the plumage. No significant differences were found between treatments and controls in the colorimetric variables hue, ultraviolet saturation, and brightness. Similarly, the avian visual model showed no perceptible changes in chromatic and achromatic signals in the individual male adults. We also analyzed the effects of estrogen and testosterone on the growth speed of the new feathers. The hormone-treated groups increased in the speed of molting compared to the control group. These results suggest that the Eared Dove is an exception to basal branch models: rather than regulating coloration, sex hormones speed up the growth of the new feathers.

Phylogenetic Analysis of the Genes in D-Ala-D-Lactate Synthesizing Glycopeptide Resistance Operons: The Different Origins of Functional and Regulatory Genes.

The phylogenetic relationships of glycopeptide resistance proteins were investigated. The amino acid sequences of vanA, vanB, vanR and vanS were used as queries to search against bacterial genomes in the NCBI RefSeq database. Hits with >60% amino acid identity and >90% query coverage were aligned, and phylogenetic trees were reconstructed. The ligase gene phylogenies were highly similar for both queries, revealing two major clusters. One contained [[vanA:vanM][vanB:vanD]vanF] and related proteins, with proteins from different Bacillaceae, mostly from Paenibacillus spp., in basal positions to all, except vanB. Ligases from streptomycetes formed the other cluster. The relative positions of vanH and vanX differed from those of the associated ligases, but the basal position of the Paenibacillus spp. and the separation of proteins of Streptomyces origin were similar. The accessory genes vanW, vanY and vanZ were associated with vanB, vanA/vanM and vanA, respectively; the basal branches were always proteins from different Bacillaceae but never from streptomycetes. Multiple homologs of the regulatory genes vanR and vanS were found in the genomes; those associated with the different ligases were unique to the ligases. Similarly to the accessory genes, vanRS from Bacillales and Clostridia, but never from streptomycetes, was found in the basal positions. In conclusion, the core genes vanA/B/D/F/M, vanH and vanX originate most probably from glycopeptide-producing streptomycetes, with Paenibacillus spp. (or other Bacillaceae) mediating the transfer, while the accessory genes and the regulatory apparatus probably originate from these Bacillaceae.

Exploration and Characterization of Host Trees and Orchid Epiphyte Zones in Lore Lindu National Park, Central Sulawesi

Host trees are vital for the survival of epiphytic orchids, providing necessary light and air circulation for optimal growth. Large trees with tall canopies contribute to the broader distribution of epiphytic orchids in forest areas. This research aimed to identify the characteristics of orchid host tree species in Lore Lindu National Park, considering both elevation zones and orchid growth zones. The research was conducted at various locations within the park, employing the field exploration survey method (cruise method). This method involved comprehensive exploration at each research site and establishing observation paths along pioneer lines, mainly where orchid host trees were found. The findings indicate the presence of 20 types of orchid host trees and 35 species of epiphytic orchids. The basal branching zone (Zone 3) was the most populated by epiphytic orchids on host trees, and the lowland forest was the elevation zone where most orchid host trees were found in Lore Lindu National Park, Central Sulawesi. Keywords: host trees, Lore Lindu National Park, orchids, zone distribution

18S rDNA sequence-structure phylogeny of the eukaryotes simultaneously inferred from sequences and their individual secondary structures

ObjectiveThe eukaryotic tree of life has been subject of numerous studies ever since the nineteenth century, with more supergroups and their sister relations being decoded in the last years. In this study, we reconstructed the phylogeny of eukaryotes using complete 18S rDNA sequences and their individual secondary structures simultaneously. After the sequence-structure data was encoded, it was automatically aligned and analyzed using sequence-only as well as sequence-structure approaches. We present overall neighbor-joining trees of 211 eukaryotes as well as the respective profile neighbor-joining trees, which helped to resolve the basal branching pattern. A manually chosen subset was further inspected using neighbor-joining, maximum parsimony, and maximum likelihood analyses. Additionally, the 75 and 100 percent consensus structures of the subset were predicted.ResultsAll sequence-structure approaches show improvements compared to the respective sequence-only approaches: the average bootstrap support per node of the sequence-structure profile neighbor-joining analyses with 90.3, was higher than the average bootstrap support of the sequence-only profile neighbor-joining analysis with 73.9. Also, the subset analyses using sequence-structure data were better supported. Furthermore, more subgroups of the supergroups were recovered as monophyletic and sister group relations were much more comparable to results as obtained by multi-marker analyses.

The JA-OsJAZ6-DELLA module controls the tillering and drought stress response in rice

Jasmonic acid (JA) plays crucial functions during plant growth and stress response, but its roles and regulatory mechanism in plant branching remain largely unknown. Rice basal branching (tillering) is an essential agronomic trait that affects crop production. Here, we report that OsJAZ6, the repressor of JA signaling, negatively modulates rice tillering and drought stress tolerance. Loss-of-function mutants of OsJAZ6 exhibit a significant increase in tiller number, while OsJAZ6ΔJas-overexpression lines produce fewer tillers than wild-type plants. Further investigations show that function loss of OsJAZ6 promotes the tiller bud growth rather than formation. Mechanistic studies show that OsJAZ6 interacts with rice DELLA/SLR1 (SLENDER RICE 1), a transcription repressor of gibberellin (GA) signaling, and the interaction promotes SLR1 degradation, which further facilitates the degradation of rice tillering regulator MOC1 (MONOCULM 1), thereby inhibiting the tiller bud growth. In agreement, the slr1 mutant exhibits fewer tillers than wild type. Consistently, application of JA promotes the growth of tiller bud and thus increases the tiller number, while GA treatment results in opposite result. Meanwhile, osjaz6 mutants display enhanced drought tolerance, coupled with increased JA sensitivity, while the slr1 mutant shows the reverse behavior. Collectively, our data demonstrate that OsJAZ6 negatively modulates rice tillering as well as drought stress tolerance by destabilizing SLR1 protein. Our data shed light on the regulatory mechanism of controlling the tiller development and drought stress response in rice by the JA-OsJAZ6-SLR1 module.

Chromosome-level genome assembly of Hippophae tibetana provides insights into high-altitude adaptation and flavonoid biosynthesis

BackgroundAs an endemic shrub of the Qinghai-Tibetan Plateau (QTP), the distribution of Hippophae tibetana Schlecht. ranges between 2800 and 5200 m above sea level. As the most basal branch of the Hippophae genus, H. tibetana has an extensive evolutionary history. The H. tibetana is a valuable tree for studying the ecological evolution of species under extreme conditions.ResultsHere, we generated a high-quality chromosome-level genome of H. tibetana. The total size of the assembly genome is 917 Mb. The phylogenomic analysis of 1064 single-copy genes showed a divergence between 3.4 and 12.8 Mya for H. tibetana. Multiple gene families associated with DNA repair and disease resistance were significantly expanded in H. tibetana. We also identified many genes related to DNA repair with signs of positive selection. These results showed expansion and positive selection likely play important roles in H. tibetana’s adaptation to comprehensive extreme environments in the QTP. A comprehensive genomic and transcriptomic analysis identified 49 genes involved in the flavonoid biosynthesis pathway in H. tibetana. We generated transgenic sea buckthorn hairy root producing high levels of flavonoid.ConclusionsTaken together, this H. tibetana high-quality genome provides insights into the plant adaptation mechanisms of plant under extreme environments and lay foundation for the functional genomic research and molecular breeding of H. tibetana.

Effect of Plant Density on Mechanical Harvest Efficiency of New Mexico Pod-type Green Chile Pepper

Summary. New Mexico green pod-type chile (Capsicum annuum) has significant importance as a vegetable crop. The cultivation and trade of New Mexico pod-type green chile are culturally significant within New Mexico (USA) and contribute to the state’s economy by providing income and employment to farmers and through supporting industries. However, because of the high cost and limited availability of labor, New Mexico pod-type green chile acreage has declined. Traditionally, New Mexico pod-type green chile is hand-harvested when the fruit are full-size but physiologically immature. To preserve and expand the production of New Mexico pod-type green chile, the adoption of mechanical harvest technologies is essential. In 2015 and 2016, experiments were conducted at New Mexico State University’s Los Lunas Agricultural Science Center (Los Lunas, NM, USA) to examine the effects of increased planting density on New Mexico pod-type green chile fruit size, plant architecture, and mechanical harvest efficiency. Two commercial New Mexico pod-type green chile cultivars, NuMex Joe E. Parker and AZ-1904, were direct-seeded on 17 Apr 2015 and 14 Apr 2016. On 11 Jun 2015 and 14 Jun 2016, three plant density treatments were implemented at 39,000 (high), 23,000 (medium), and 15,000 (standard) plants/acre. Before harvest, plant measurements, including height, width, height to first bifurcation, stem diameter, and number of lateral basal branches, were obtained. Plots were mechanically harvested using an inclined double helix harvester, and harvested material was sorted into marketable green fruit, machine-broken fruit, and nonpod plant material. Fruit measurements, including fruit weight, width, length, pericarp thickness, and number of locules, were obtained. Both cultivars exhibited a 9% increase in height to bifurcation accompanied by fewer basal branches grown at high density. Plant density did not significantly affect the fruit length, width, number of locules, and pericarp thickness. Plants grown at high density had an increased percentage of marketable fruit, with ‘NuMex Joe E. Parker’ having a higher percentage of marketable green fruit compared to ‘AZ-1904’. The results demonstrated that an increase in planting density in production fields to 39,000 plants/acre coupled with cultivar selection enhanced efficiency in a mechanical harvest system.

Phylogeny of Transferable Oxazolidinone Resistance Genes and Homologs.

Oxazolidinone resistance, especially transmissible resistance, is a major public health concern, and the origin of this resistance mechanism is not yet resolved. This study aims to delve into the phylogenetic origin of the transmissible oxazolidinone resistance mechanisms conferring cross-resistance to other drugs of human and veterinary importance. The amino acid sequences of the five cfr ribosomal methylases and optrA and poxtA were used as queries in searches against 219,549 bacterial proteomes in the NCBI RefSeq database. Hits with >40% amino acid identity and >80% query coverage were aligned, and phylogenetic trees were reconstructed. All five cfr genes yielded highly similar trees, with rlmN housekeeping ribosomal methylases located basal to the sister groups of S-adenosyl-methionine-dependent methyltransferases from various Deltaproteobacteria and Actinomycetia, including antibiotic-producing Streptomyces species, and the monophyletic group of cfr genes. The basal branches of the latter contained paenibacilli and other soil bacteria; they then could be split into the clades [cfr(C):cfr(E)] and [[cfr:cfr(B)]:cfr(D)], always with different Bacillaceae in their stems. Lachnospiraceae were encountered in the basal branches of both optrA and poxtA trees. The ultimate origin of the cfr genes is the rlmN housekeeping ribosomal methylases, which evolved into a suicide-avoiding methylase in antibiotic producers; a soil organism (Lachnospiraceae, Paenibacilli) probably acted as a transfer organism into pathogenic bacteria. In the case of optrA, the porcine pathogenic Streptococcus suis was present in all branches, while the proteins closest to poxtA originated from Clostridia.

Influence of white-light-emitting diodes on primary visual cortex layer 5 pyramidal neurons (V1L5PNs) and remodeling by blue-light-blocking lenses

Studies have explored the consequences of excessive exposure to white-light-emitting diodes (LEDs) in the retina. Hence, we aimed to assess the implications of such exposure on structural alterations of the visual cortex, learning and memory, and amelioration by blue-light-blocking lenses (BBLs). Eight-week-old Wistar rats (n = 24) were used for the experiment and divided into four groups (n = 6 in each group) as control, white LED light exposure (LE), BBL Crizal Prevencia-1 (CP), and DuraVision Blue-2 (DB). Animals in the exposure group were exposed to white LED directly for 28 days (12:12-h light/dark cycle), whereas animals in the BBL groups were exposed to similar light with BBLs attached to the LEDs. Post-exposure, a Morris water maze was performed for memory retention, followed by structural analysis of layer 5 pyramidal neurons in the visual cortex. We observed a significant difference (P < 0.001) in the functional test on day 1 and day 2 of training in the LE group. Structural analysis of Golgi-Cox-stained visual cortex layer 5 pyramidal neurons showed significant alterations in the apical and basal branching points (p < 0.001) and basal intersection points (p < 0.001) in the LE group. Post hoc analysis revealed significant changes between (p < 0.001) LE and CP and (p < 0.001) CP and DB groups. Constant and cumulative exposure to white LEDs presented with structural and functional alterations in the visual cortex, which are partly remodeled by BBLs.

Gleaning Euglenozoa-specific DNA polymerases in public single-cell transcriptome data

Multiple genes encoding family A DNA polymerases (famA DNAPs), which are evolutionary relatives of DNA polymerase I (PolI) in bacteria and phages, have been found in eukaryotic genomes, and many of these proteins are used mainly in organelles. Among members of the phylum Euglenozoa, distinct types of famA DNAP, PolIA, PolIBCD+, POP, and eugPolA, have been found. It is intriguing how the suite of famA DNAPs had been established during the evolution of Euglenozoa, but the DNAP data have not been sampled from the taxa that sufficiently represent the diversity of this phylum. In particular, little sequence data were available for basal branching species in Euglenozoa until recently. Thanks to the single-cell transcriptome data from symbiontids and phagotrophic euglenids, we have an opportunity to cover the “hole” in the repertory of famA DNAPs in the deep branches in Euglenozoa. The current study identified 16 new famA DNAP sequences in the transcriptome data from 33 phagotrophic euglenids and two symbiontids, respectively. Based on the new famA DNAP sequences, the updated diversity and evolution of famA DNAPs in Euglenozoa are discussed.

Mycobacteriales taxonomy using network analysis-aided, context-uniform phylogenomic approach for non-subjective genus demarcation.

A robust taxonomy is essential for the organized study of prokaryotes and the effective communication of microbial knowledge. The genus rank is the mainstay of biological classification as it brings together under a common name a group of closely related organisms sharing the same recent ancestry and similar characteristics. Despite the unprecedented resolution afforded by whole-genome sequencing in defining evolutionary relationships, a consensus approach for phylogenomics-based prokaryotic genus delineation remains elusive. Taxonomists use different demarcation criteria, sometimes leading to genus rank over-splitting and the creation of multiple new genera. This work reports a simple, reliable, and standardizable method that seeks to minimize subjectivity in genomics-based demarcation of prokaryotic genera, exemplified through application to the order Mycobacteriales. Formal descriptions of proposed taxonomic changes based on our study are included.

Validity of using serum D-dimer titer in prefatory to computed Tomography pulmonary angiography scans in the early identification of pulmonary embolism amid emergency room patients: a single-center retrospective observational study

Background and aim Pulmonary embolism emerges when a thrombus forms in the veins or right heart and travels to the pulmonary arteries. The study aims to ascertain the robustness of D-dimer testing for PE compared with CTPA and identify the threshold values to support its use. Patients and methods The positivity threshold for D-dimer was above 250 ng/ml. CTPA was performed after performing blood sampling. Patients were managed in the ICU with anticoagulants by parenteral use. The most commonly used items were heparin, either unfractionated (UFH) or low-molecular-weight heparin (LMWH). Results Twenty-four patients of the total number of cases were positive for CTPA, while four patients were negative for PE by CTPA. Embolism was detected in the anterior, posterior, medial, and lateral basal segmental branches of the right lung, the lateral, posterior, and anterior basal segmental branches of the left lung, and the posterior segmental branch of the left lung. The D-dimer test and CTPA both provided similarly accurate PE diagnoses with no significant differences between them. There were 28 patients in total, three of those patients had D-dimer levels below the cutoff value of 250 ng/ml, whereas the remaining 25 had D-dimer levels over the diagnostic threshold. Those with a positive CTPA diagnosis of PE had greater levels of D dimers than those with a negative CTPA diagnosis of PE. Conclusion D-dimer levels can help in guiding the option of CTPA and the initiation of treatment for patients with suspected PE.

Multivariate analysis for yield and yield-related traits of amaranth genotypes from Ethiopia

The genus Amaranthus is one of the few dicotyledonous, non-grass mesophytes that use specialized C4 annuals or short-lived perennials to produce significant amounts of edible small-seeded pseudo cereals. In this study, we characterized the genetic diversity of 120 genotypes of amaranths collected from diverse amaranth-growing regions of Ethiopia using multivariate analysis of yield and yield-related traits. The experiments were carried out at Hawassa University, in the years 2020 and 2021. The experimental design was set up using an alpha lattice design and replicated two times. The collected data were examined for 24 descriptors. Principal component analysis showed that the first six principal components with eigenvalues greater than one contributed 80.41% of the variability. However, the first two principal components explained 52.42% of the total variation. The highest contributing traits in the first component were days to flowering, basal stem diameter, plant height at flowering, plant height at maturity, auxiliary inflorescence length, number of branches, terminal inflorescence lateral length, days to maturity, terminal inflorescence stalk length, leaf number, leaf length, top lateral branch length. The traits with the greatest weight on the second component were leaf area, basal lateral branch length, leaf length, and leaf width, grain filling period, grain sinking filling rate, and grain yield. Therefore, selection based on these traits would be effective for yield improvement in amaranth genotypes. Additionally, the hierarchical clustering grouped all the genotypes into five clusters. The pairwise generalized squared distance (D2) among the five clusters based on Mahalanobis's D2 statistics revealed the maximum and highly significant genetic distance was observed between II and III (277.79), while the minimum inter-cluster distance observed between clusters I and II (39.50). The findings suggest that amaranth genotypes in Ethiopia have a lot of genetic variation, which might be used for future breeding and ought to be conserved.

New evidence for the antiquity of Desmostylus (Desmostylia) from the Skooner Gulch Formation of California.

Desmostylus is an extinct marine mammal genus that belongs to Desmostylia, a clade of extinct herbivorous mammals. While desmostylian remains are widely reported from Paleogene and Neogene marine strata of the North Pacific Rim, occurrences of the genus Desmostylus are almost entirely limited to middle Miocene strata, with only a few early Miocene records from Japan. Here we report a Desmostylus tooth from the earliest Miocene (Aquitanian) Skooner Gulch Formation in northern California, USA. This specimen exhibits cuspules around the crown, a primitive trait of the subfamily Desmostylidae, as seen in more basal branching desmostylid taxa such as Cornwallius and Ounalashkastylus, but with a high tooth crown and thickened enamel. The specimen is also diagnostically different from all other desmostylid genera, such as Cornwallius, and Ounalashklastylus. The Aquitanian age of the Skooner Gulch Formation implies that the distinctive tooth morphology of Desmostylus has persisted, largely unchanged, for more than 15 million years and that desmostylids possibly originated in western North America.

Morphological characterization, variability, and diversity among amaranth genotypes from Ethiopia

Amaranths are versatile, dicotyledonous plants with the potential for high yields. It has been extensively investigated as a model C4 plant. They have great photosynthetic performance as a result of eliminating the rival photorespiration mechanism. This increases the advantages of expanding the adaptation and cultivation of amaranth in Ethiopia. The objectives of the current study were to estimate genetic diversity, heritability, and genetic advance for yield and yield-contributing traits of amaranth genotypes based on agro-morphological traits. One hundred twenty amaranth genotypes were evaluated over two years using an alpha lattice design with two replications. The analysis of variance indicated that the mean square due to year and genotype-by-year interaction varied significantly for most measured traits. The estimates of variability, heritability, and genetic advance found in this study indicate the incredible genetic diversity in amaranth genotypes and the strength of selection response for these traits in the population. The findings showed that very high to moderately high heritability, high to moderate genetic advance, and genetic variability was observed for the traits basal lateral branch length, axillary inflorescence length, leaf area, branch number, plant height at flowering, plant height at maturity, stem diameter, days to flowering, grain filling periods, leaf width, and leaf length. Furthermore, the potential for amaranth improvement through appropriate selection is revealed by the existence of significant differences between the number of superior and inferior genotypes for the majority of examined traits. This suggests that these traits are governed more by additive gene action and that selection based on these traits might be successful in achieving the desired genetic gains for improvement.

Mite diversity and intra-plant distribution in mango crop

Effective management of arthropod communities in agricultural environments requires knowledge of the diversity and distribution of species that inhabit host crops. Therefore, we conducted this study to evaluate the richness, abundance, and intra-plant distribution of the most abundant mite species in mango plants. Leaves or reproductive structures were collected monthly considering the different canopy quadrants (North, South, East, and West), the position of the branch (basal, median, and apical), and, in the case of leaves, their position on the branch (basal, median, and apical). A total of 28 species belonging to 12 mite families were identified. Cisaberoptus kenyae, Vilaia pamithus, and Oligonychus mangiferus were the most abundant phytophagous species, accounting for 87%, 6%, and 3% of the total number of mites collected, respectively. Vilaia pamithus was the most abundant species in the southern quadrant. Amblyseius largoensis (Phytoseiidae) and Cunaxa sp1. (Cunaxidae) were the most abundant among the predators (15.1% and 13.1%, respectively). The highest level of diversity was observed in the basal and median leaves of the basal and median branches of mangoes. The intra-plant distribution of these species was influenced by plant architecture and geographical position. Most species were found on mango leaves, whereas other species colonized inflorescences and/or fruits, but at low densities. In this study, we found considerable diversity of phytophagous and predator mites in mango plants. These predator mites may be crucial for controlling mango pests.