Vigna Vexillata Research Articles

Identification of novel QTLs for salt tolerance in zombi pea (Vigna vexillata)

Identification of novel QTLs for salt tolerance in zombi pea (Vigna vexillata)

Nutritional status of Zombi pea (Vigna vexillata) as influenced by plant density and deblossoming

Feeding billions, a healthy and nutritious diet in the era of climate change is a major challenge before plant breeders, geneticists and agronomist. In this context, the continuous search for adaptive and nutritious crops could be a better alternative to combat the problems of hunger and malnutrition. The zombi pea, a nutritious and underutilized leguminous vegetable, is one of such better alternatives to feed billions a nutritious food besides being a potential gene source for breeding abiotic stress resistant varieties. To evaluate its potential as a wonder crop in the tropical and subtropical regions of India, the nutritional status of tubers, pods and pericarp were investigated under different treatments of plant spacings and deblossoming. The experiment was conducted in split plot design with three replications and eight treatments during 2021–2022 in the coastal regions of India. The nutrient profiling in tubers and pericarp of pods in zombi pea revealed higher accumulation of nutrients viz. potassium (K), magnesium (Mg), iron (Fe), manganese (Mn) and zinc (Zn) with blossom retention. The zombi pea tubers reflected significantly high protein accumulation with the increase in plant spacing. The results pertaining to nutrient profiling in the pods of zombi pea indicated that the plant spacing has no significant effect on the accumulation of majority of nutrients under study. The above-mentioned findings are conspicuously novel and valuable. The present study would pave the way for understanding nutritional importance and breeding potential of this orphan crop. The blossom retention renders higher nutrient accumulation in tubers, pods and pericarp of zombi pea. Deblossoming has no significant influence on nutritional profile of this wonder crop but, wider spacing is effective in producing tubers with high protein content.

Genotypic variations in phosphorus accumulation in wild cowpea relatives (Vigna vexillata) grown under phosphorus deficiency

ABSTRACT Vigna vexillata is a wild cowpea relative inhabiting tropical and subtropical regions. Because phosphorous (P) deficient soils are widely found in these regions, such wild relatives may have an ability to efficiently capture and utilize P in soils and thus can be potential materials of green manure to improve soil-plant nutrient cycles and subsequent crop production. Genotypic variations in shoot P content were evaluated in P-deficient (−P) and P-fertilized (+P) conditions of the pot experiment to clarify the ability of P accumulation in V. vexillata. Among the 14 accessions, five with a high shoot P content under P deficiency were identified. The high shoot P contents were attributed to large shoot biomass rather than high shoot P concentrations. The larger biomass of these accessions was consistent under the -P and +P conditions, indicating that potential growth characteristics without P restriction were a major driving factor of P accumulation even under P deficiency. In contrast, accessions with low shoot P content had small shoot biomass with high P concentrations. These accessions exhibited superior drought tolerance than those with large shoot biomass, presumably because of the small water consumption due to the small shoot biomass. The trade-offs between the shoot P accumulation and drought tolerance should be considered for genotype selection under the conditions where P deficiency and drought risks are often complex.

Translocations and inversions: major chromosomal rearrangements during Vigna (Leguminosae) evolution.

Inversions and translocations are the major chromosomal rearrangements involved in Vigna subgenera evolution, being Vigna vexillata the most divergent species. Centromeric repositioning seems to be frequent within the genus. Oligonucleotide-based fluorescence in situ hybridization (Oligo-FISH) provides a powerful chromosome identification system for inferring plant chromosomal evolution. Aiming to understand macrosynteny, chromosomal diversity, and the evolution of bean species from five Vigna subgenera, we constructed cytogenetic maps for eight taxa using oligo-FISH-based chromosome identification. We used oligopainting probes from chromosomes 2 and 3 of Phaseolus vulgaris L. and two barcode probes designed from V. unguiculata (L.) Walp. genome. Additionally, we analyzed genomic blocks among the Ancestral Phaseoleae Karyotype (APK), two V. unguiculata subspecies (V. subg. Vigna), and V. angularis (Willd.) Ohwi & Ohashi (V. subg. Ceratotropis). We observed macrosynteny for chromosomes 2, 3, 4, 6, 7, 8, 9, and 10 in all investigated taxa except for V. vexillata (L.) A. Rich (V. subg. Plectrotropis), in which only chromosomes 4, 7, and 9 were unambiguously identified. Collinearity breaks involved with chromosomes 2 and 3 were revealed. We identified minor differences in the painting pattern among the subgenera, in addition to multiple intra- and interblock inversions and intrachromosomal translocations. Other rearrangements included a pericentric inversion in chromosome 4 (V. subg. Vigna), a reciprocal translocation between chromosomes 1 and 5 (V. subg. Ceratotropis), a potential deletion in chromosome 11 of V. radiata (L.) Wilczek, as well as multiple intrablock inversions and centromere repositioning via genomic blocks. Our study allowed the visualization of karyotypic patterns in each subgenus, revealing important information for understanding intrageneric karyotypic evolution, and suggesting V. vexillata as the most karyotypically divergent species.

A Gene Encoding Xylanase Inhibitor Is a Candidate Gene for Bruchid (Callosobruchus spp.) Resistance in Zombi Pea (Vigna vexillata (L.) A. Rich).

Two bruchid species, Callosobruchus maculatus and Callosobruchus chinensis, are the most significant stored insect pests of tropical legume crops. Previously, we identified a major QTL, qBr6.1, controlling seed resistance to these bruchids in the cultivated zombi pea (Vigna vexillata) accession 'TVNu 240'. In this study, we have narrowed down the qBr6.1 region and identified a candidate gene conferring this resistance. Fine mapping using F2 and F2:3 populations derived from a cross between TVNu 240 and TVNu 1623 (susceptible) revealed the existence of two tightly linked QTLs, designated qBr6.1-A and qBr6.1-B, within the qBr6.1. The QTLs qBr6.1-A and qBr6.1-B explained 37.46% and 10.63% of bruchid resistance variation, respectively. qBr6.1-A was mapped to a 28.24 kb region containing four genes, from which the gene VvTaXI encoding a xylanase inhibitor was selected as a candidate gene responsible for the resistance associated with the qBr6.1-A. Sequencing and sequence alignment of VvTaXI from TVNu 240 and TVNu 1623 revealed a 1-base-pair insertion/deletion and five single-nucleotide polymorphisms (SNPs) in the 5' UTR and 11 SNPs in the exon. Alignment of the VvTAXI protein sequences showed five amino acid changes between the TVNu 240 and TVNu 1623 sequences. Altogether, these results demonstrated that the VvTaXI encoding xylanase inhibitor is the candidate gene conferring bruchid resistance in the zombi pea accession TVNu 240. The gene VvTaXI will be useful for the molecular breeding of bruchid resistance in the zombi pea.

Genome resources for underutilised legume crops: genome sizes, genome skimming and marker development

Underutilised crops suffer from under-investigation relative to more mainstream crops, but often possess improved stress tolerance and/or nutrition, making them potentially important for breeding programmes in the context of climate change and an expanding human population. Developing basic genome resources for underutilised crops may therefore catalyse analyses to facilitate their use, through improved understanding of population structure, phylogeny, candidate genes, and linkage mapping. We carried out nuclear and plastid genome sequencing and assembly for five underutilised legumes: jack bean, sword bean, Kersting’s groundnut, moth bean, and zombi pea. Using only ‘off-the-shelf’, free-to-use bioinformatic tools, we also developed a simple but effective pipeline to identify thousands of markers, which could be applied in other species. We assembled 53–68% of the genome and 73–95% of the gene space in the five legumes. The assemblies were fragmented but nevertheless useful for identifying between 34,000—60,000 microsatellites. Examination of 32 markers in zombi pea revealed 16 primer pairs which amplified in at least half of the eight accessions tested and were polymorphic. We also present nuclear genome size estimates for 17 legume taxa (12 for the first time), comprising the above five species as well as other domesticated legume species and crop wild relatives. We aim for the newly developed markers and genome size estimates presented here to be useful for the research community by aiding genomic and population genetic studies for these taxa, and to provide information on approaches that can be applied for investigating other important yet underutilised crops.

New records and addition to the flora of Saudi Arabia, mainly from Faifa Governorate, Jazan Region

Based on vegetation surveys made in the southern region of Saudi Arabia between 2020 and 2021, five new plant taxa including four species and one subspecies, belonging to four families that had not previously been recorded in Saudi Arabia's flora were discovered. Within the Arabian Peninsula, all newly recorded species (i.e., Alysicarpus vaginalis (L.) DC. (Fabaceae), Commiphora schimperi (O.Berg) Engl. (Burseraceae), Maerua angolensis DC. subsp. angolensis (Capparaceae), Peperomia leptostachya Hook. & Arn. (Piperaceae), and Vigna vexillata (L.) A.Rich. (Fabaceae) were recorded in Yemen while A. vaginalis was also recorded in Oman. Brief descriptions and comments on the phytogeography of each taxon are given. The distribution of plants in Faifa Mountains and surrounding areas was mapped using geographic information systems (GIS) and ground surveys.

Vignette of Vigna domestication: From archives to genomics.

The genus Vigna comprises fast-growing, diploid legumes, cultivated in tropical and subtropical parts of the world. It comprises more than 200 species among which Vigna angularis, Vigna radiata, Vigna mungo, Vigna aconitifolia, Vigna umbellata, Vigna unguiculata, and Vigna vexillata are of enormous agronomic importance. Human selection along with natural variability within these species encompasses a vital source for developing new varieties. The present review convokes the early domestication history of Vigna species based on archeological pieces of evidence and domestication-related traits (DRTs) together with genetics of domestication. Traces of early domestication of Vigna have been evidenced to spread across several temperate and tropical regions of Africa, Eastern Asia, and few parts of Europe. Several DRTs of Vigna species, such as pod shattering, pod and seed size, dormancy, seed coat, seed color, maturity, and pod dehiscence, can clearly differentiate wild species from their domesticates. With the advancement in next-generation high-throughput sequencing techniques, exploration of genetic variability using recently released reference genomes along with de novo sequencing of Vigna species have provided a framework to perform genome-wide association and functional studies to figure out different genes related to DRTs. In this review, genes and quantitative trait loci (QTLs) related to DRTs of different Vigna species have also been summarized. Information provided in this review will enhance the in-depth understanding of the selective pressures that causes crop domestication along with nature of evolutionary selection made in unexplored Vigna species. Furthermore, correlated archeological and domestication-related genetic evidence will facilitate Vigna species to be considered as suitable model plants.

Evaluation of black gram (Vigna mungo) genepool against Callosobruchus maculatus and diversity analysis inter se

The present study was carried out at ICAR-National Bureau of Plant Genetic Resources, New Delhi during 2020–21to evaluate the differential reaction of 69 germplasm accessions representing black gram [Vigna mungo (L.) Hepper] landraces and its crop wild relatives for resistance against Callosobruchus maculatus (Fab.) under artificial infestation et-up using ‘No-choice test’ method and analyze their genetic diversity using SSR markers. After emergence of adult beetles, the accessions were studied for the growth parameters like total oviposition, exit holes, adult emergence (AE), per cent seed weight loss (PSWL) and growth index (GI), which varied significantly. Based on the key traits, viz. AE and PSWL, the accessions were categorized into six groups, viz. immune (I), resistant (R), moderately resistant (MR), moderately susceptible (MS), susceptible (S) and highly susceptible (HS). Accessions IC259504 (Vigna vexillata) and IC424616 (Vigna mungo) were immune and resistant to bruchid infestation respectively. Moreover, the genetic diversity parameters such as allele number, PIC values and observed heterozygosity indicated considerable diversity among the accessions. The reported immune and resistant accessions could be used as donor parents in the Vigna breeding programme for transferring bruchid resistance factor(s) to agronomically superior cultivars.

Revisiting the Domestication Process of African Vigna Species (Fabaceae): Background, Perspectives and Challenges.

Legumes are one of the most economically important and biodiverse families in plants recognised as the basis to develop functional foods. Among these, the Vigna genus stands out as a good representative because of its relatively recent African origin as well as its outstanding potential. Africa is a great biodiversity centre in which a great number of species are spread, but only three of them, Vigna unguiculata, Vigna subterranea and Vigna vexillata, were successfully domesticated. This review aims at analysing and valorising these species by considering the perspective of human activity and what effects it exerts. For each species, we revised the origin history and gave a focus on where, when and how many times domestication occurred. We provided a brief summary of bioactive compounds naturally occurring in these species that are fundamental for human wellbeing. The great number of wild lineages is a key point to improve landraces since the domestication process caused a loss of gene diversity. Their genomes hide a precious gene pool yet mostly unexplored, and genes lost during human activity can be recovered from the wild lineages and reintroduced in cultivated forms through modern technologies. Finally, we describe how all this information is game-changing to the design of future crops by domesticating de novo.

Identification and development of key descriptors for phenotypic characterization of tuber cowpea [Vigna vexillata (L.) A. Rich.

Identification and development of key descriptors for phenotypic characterization of tuber cowpea [Vigna vexillata (L.) A. Rich.

Morphological studies on legume and hilum in seven species of Vigna Savi (Fabaceae)

In this study of different taxa of genus Vigna the macro and micromorphological characters were investigated. These taxa collected from different countries (3 cultivated and 8 annual or perennial herbs) representing 7 species of this genus, namely: Vigna radiate, Vigna trilobata, Vigna vexillata, Vigna caracalla, Vigna pubescens, Vigna unguiculata, and Vigna luteola. Legume features such as shape, colour, size, surface texture, number of locules, number of legumes per peduncle seed set percentage, orientation. Moreover, by using scanning electron microscopy, additional details were obtained for stomatal shape, size, type, cuticular and wax ornamentation of the surface of the mature pod, including details of the seed such as hilum shape, size, position, ornamentation based on scanning electron microscope evidence. The usefulness of the macro and micromorphological features as criteria for taxonomic identification was emphasized. Key words: Vigna, Fabaceae, morphological characters, pod, hilum, S.E.M., taxonomy.

Identification and resistant characterization of legume sources against Meloidogyne incognita

Root-knot nematodes (RKNs; Meloidogyne spp.) are becoming a serious problem in legume production. This study identified Vigna genotypes exhibiting resistance to M. incognita (RKN) and characterized the modes of the resistance to M. incognita. In total, 279 accessions from 21 Vigna species were screened for resistance based on a galling index (GI) and an egg mass index (EI). Seven accessions were highly resistant to RKN with GI≤25, namely JP74716 (V. mungo var. mungo; cultivated black gram), JP107881 (V. nepalensis), JP229392 (V. radiata var. sublobata; wild mungbean), AusTRCF118141 (V. unguiculata subsp. unguiculata; cultivated cowpea), AusTRCF306385 (V. unguiculata subsp. unguiculata), AusTRCF322090 (V. vexillata var. vexillata; wild zombi pea) and JP235929 (V. vexillata var. vexillata). JP229392 and AusTRCF322090 were the most resistant accessions having EI values of 18.74 and 1.88, respectively. Continuous culture of M. incognita on both JP229392 and AusTRCF322090 resulted in a weakness in pathogenic ability for this RKN. The resistance in JP229392 and AusTRCF322090 to RKN appeared to be antibiosis that was associated with reduced nematode penetration, retardation of nematode development and impeding giant cell formation. The Vigna germplasm resistance to RKN identified in this study could be utilized as gene sources for the development of RKN-resistant Vigna cultivars.

Morphological and nutritional assessment of Vigna vexillata (L.) A. Rich.: a potential tuberous legume of India

Vigna vexillata (L.) A. Rich. is a tropical tuberous legume which is fascinating for multiple uses in India. It is a climate-resilient legume and reported as a source of bruchid resistance, abiotic stresses tolerance and proteinaceous tubers. Meagre information is available for storage roots (tubers) of V. vexillata in general in the Indian scenario. In the present study, the evaluation of morphological and nutritional traits of storage roots are presented along with the genetic resources study. Herbarium study verified its wide distribution and occurrence in India since ancient time. Significant variability was observed for tuber morphological traits and nutritional parameters. Among accessions studied, IC259504 was identified promising agronomically and nutritionally both. Protein content in tubers of V. vexillata was recorded up to eightfold higher than that in sweet potato and tapioca. Results indicated that this species has the potential to meet the future needs of food and nutritional security and further utilization in Vigna improvement programme.

Identification of QTLs for Domestication-Related Traits in Zombi Pea [Vigna vexillata (L.) A. Rich], a Lost Crop of Africa.

Zombi pea [Vigna vexillata (L.) A. Rich] is a legume crop found in Africa. Wild zombi pea is widely distributed throughout the tropical and subtropical regions, whereas domesticated zombi pea is rarely cultivated. Plant domestication is an evolutionary process in which the phenotypes of wild species, including seed dormancy, pod shattering, organ size, and architectural and phenological characteristics, undergo changes. The molecular mechanism underlying the domestication of zombi pea is relatively unknown. In this study, the genetic basis of the following 13 domestication-related traits was investigated in an F2 population comprising 198 individuals derived from a cross between cultivated (var. macrosperma) and wild (var. vexillata) zombi pea accessions: seed dormancy, pod shattering, days-to-flowering, days-to-maturity, stem thickness, stem length, number of branches, leaf area, pod length, 100-seed weight, seed width, seed length, and seeds per pod. A genetic map containing 6,529 single nucleotide polymorphisms constructed for the F2 population was used to identify quantitative trait loci (QTLs) for these traits. A total of 62 QTLs were identified for the 13 traits, with 1–11 QTLs per trait. The major QTLs for days-to-flowering, stem length, number of branches, pod length, 100-seed weight, seed length, and seeds per pod were clustered in linkage group 5. In contrast, the major QTLs for seed dormancy and pod shattering belonged to linkage groups 3 and 11, respectively. A comparative genomic analysis with the cowpea [Vigna unguiculata (L.) Walp.] genome used as the reference sequence (i.e., the genome of the legume species most closely related to zombi pea) enabled the identification of candidate genes for the major QTLs. Thus, we revealed the genomic regions associated with domestication-related traits and the candidate genes controlling these traits in zombi pea. The data presented herein may be useful for breeding new varieties of zombi pea and other Vigna species.

Introgression Breeding in Cowpea [Vigna unguiculata (L.) Walp.

The narrow base of genetic diversity characteristic of cowpea can be attributed to it being self-pollinating, evolving from narrow wild germplasm and exhibiting very limited gene flow between wild and cultivated types. Backcrossing to introduce simply inherited desirable traits and utilization of improved breeding lines and varieties as parents in crossing programs further narrowed the genetic base of cowpea varieties. In most cowpea breeding programs, genes for resistance and market traits were pyramided into lines characterized by high levels of acceptance to farmers and consumers. Besides predisposing widely distributed improved varieties to genetic vulnerability, a narrow base of genetic variation may be contributing to the plateauing in cowpea grain yield, which compromises genetic gains. Cross compatible wild relatives have not been used in variety development because breeders shy away from them due to their tiny seed size, unattractive seed coat color and texture, pod shattering, and susceptibility to viruses. A number of wild cowpea relatives, both within and outside section Catiang of Vigna species, have been evaluated for their reaction to cowpea insect pests and diseases. Vigna vexillata lines were resistant to the legume pod borer (Maruca vitrata), the cowpea weevil (Callosobruchus maculatus), and Striga gesnerioides but are cross incompatible with cultivated cowpea. Some lines among the cross compatible wild relative V. unguiculata ssp. dekindtiana were found to be resistant to aphid in the seedling stage, while others showed good levels of drought and heat tolerance. Molecular markers are being generated to identify quantitative trait loci (QTL) with effects on some desirable attributes in cowpea. Modern breeding tools, including transgenics, can be applied for the improvement of cowpea, bypassing the natural barriers of traditional breeding. Transgenic cowpea with Bt gene cry1Ab showing resistance to M. vitrata has been released in Nigeria. Genome editing, a powerful emerging tool, can also be used for developing improved cowpea varieties with durable resistance to pests and diseases.

Traditional Practices and Consumer Habits regarding Consumption of Underutilised Vegetables in Kilimanjaro and Morogoro Regions, Tanzania.

Background Wild vegetables serve an important purpose in the health and diet of many people residing in the rural areas. Various traditional practices associated with their processing and consumption are uncommon and unknown to the present generation, resulting to their underutilization. Methods Qualitative data were obtained through focus group discussions (FGDs), key informant interviews (KIIs), and participant observation. Using a checklist and questionnaire, a total of 120 individuals from 120 randomly selected households in Kilimanjaro and Morogoro regions were interviewed. Results. Underutilised indigenous vegetables from Morogoro and Kilimanjaro regions were investigated. Out of 40 vegetables, four underutilised vegetables (UVs), Sunga (Launea cornuta), Kikundembala (Vigna vexillata), Mokiki (Momordica foetida), and Inyiri (Basella alba), were identified, collected, and studied. Over 75% of respondents preferred UVs to exotic species, the likes of cabbage, amaranth, eggplant, pumpkin leaves, and spinach. It was further noted that with the existing myths and fads associated with consumption of UVs, as well as the widespread use of the exotic vegetable species among the modern generation, UVs' future demand is diminishing. Conclusion There are many varieties of UVs in Morogoro and Kilimanjaro regions. However, the UVs are currently showing decreasing demand due to various reasons including difficulties in preparation, low palatability, and negative image to consumers; introduction of exotic species of vegetables was found to further suppress the use of UVs.

Agro-Morphological Exploration of Some Unexplored Wild Vigna Legumes for Domestication

The domestication of novel or hitherto wild food crops is quickly becoming one of the most popular approaches in tackling the challenges associated with sustainable food crop production, especially in this era, where producing more food with fewer resources is the need of the hour. The crop breeding community is not yet completely unanimous regarding the importance of crop neo-domestication. However, exploring the unexplored, refining unrefined traits, cultivating the uncultivated, and popularizing the unpopular remain the most adequate steps proposed by most researchers to achieve the domestication of the undomesticated for food and nutrition security. Therefore, in the same line of thought, this paper explores the agro-morphological characteristics of some wild Vigna legumes from an inquisitive perspective to contribute to their domestication. One hundred and sixty accessions of wild Vigna legumes, obtained from gene banks, were planted, following the augmented block design layout of two agro-ecological zones of Tanzania, during the 2018 and 2019 main cropping seasons for agro-morphological investigations. The generalized linear model procedure (GLM PROC), two-way analysis of variance (two-way ANOVA), agglomerative hierarchical clustering (AHC) and principal component analysis (PCA) were used to analyze the accession, block and block vs. accession effects, as well as the accession × site and accession × season interaction grouping variations among accessions. The results showed that the wild species (Vigna racemosa; Vigna ambacensis; Vigna reticulata; and Vigna vexillata) present a considerable variety of qualitative traits that singularly exist in the three studied checks (cowpea, rice bean, and a landrace of Vigna vexillata). Of the 15 examined quantitative traits, only the days to flowering, pods per plant, hundred seed weight and yield were affected by the growing environment (accession × site effect), while only the number of flowers per raceme and the pods per plant were affected by the cropping season (accession × season effect). All the quantitative traits showed significant differences among accessions for each site and each season. The same result was observed among the checks, except for the seed size trait. The study finally revealed three groups, in a cluster analysis and 59.61% of the best variations among the traits and accessions in PCA. Indications as to the candidate accessions favorable for domestication were also revealed. Such key preliminary information could be of the utmost importance for the domestication, breeding, and improvement of these species, since it also determines their future existence—that is, so long as biodiversity conservation continues to be a challenging concern for humanity.

The Therapeutic Properties of Plants Used Traditionally to Treat Gastrointestinal Disorders on Groote Eylandt, Australia.

The First Australians had well-developed healing systems. Groote Eylandt inhabitants used a variety of plant species to treat diarrhoea and other gastrointestinal illnesses. This study was undertaken to test, identify, and evaluate traditional medicines to treat these conditions against gastrointestinal bacterial, protozoal, and viral pathogens, as well as against cancer cell proliferation. Six plant species (Buchanania obovata Engl., Casuarina equisetifolia L., Eucalyptus tetrodonta F. Muell., Planchonia careya (F. Muell.) R. Knuth, Terminalia carpentariae C. T. White, and Vigna vexillata (L.) A. Rich.) were selected from a survey of a panel of elders from the Warnindhilyagwa tribe and compared with the published literature. Decoctions prepared according to traditional methods were screened for growth inhibitory activity of a panel of diarrhoea-causing bacterial pathogens by disc diffusion and liquid dilution MIC assays. Inhibitory activity against the gastrointestinal protozoal parasite Giardia duodenalis and antiproliferative activity against human colorectal (Caco2) and cervical (HeLa) cancer cell lines were evaluated using MTS-based colorimetric cell proliferation assays. Preliminary antiviral screening was accomplished using an MS2 bacteriophage plaque reduction assay. Toxicity was evaluated using Artemia franciscana nauplii mortality and HDF cell viability bioassays. All traditional medicines tested inhibited bacterial growth, often with MIC values substantially <1000 μg/mL. T. carpentariae was particularly noteworthy, with MIC values of 230–350 μg/mL against Citrobacter freundii, Salmonella newport, Shigella sonnei, Staphylococcus aureus, and Staphylococcus epidermidis. This species also had MICs 450–950 μg/mL against all other bacterial pathogens. B. obovata Engl. and E. tetrodonta were also good inhibitors of bacterial growth, albeit with substantially higher MIC values than determined for T. carpentariae. The T. carpentariae decoction was also the best inhibitor of MS2 phage replication (IC50 = 427 μg/mL) and Caco2 and HeLa proliferation (IC50 values of 885 and 85 μg/mL, respectively). None of the extracts were particularly strong inhibitors of Giardia duodenalis growth. All decoctions were nontoxic in the Artemia nauplii and HDF cell viability bioassays, indicating their suitability for therapeutic use.

Detection of quantitative trait loci for salt tolerance in zombi pea [Vigna vexillata (L.) A. Rich

Zombi pea [Vigna vexillata (L.) A. Rich] is an underutilized legume crop, with highly diverse wild species that carry genes conferring resistance to several biotic and abiotic stresses. The objective of this study was to construct a zombi pea genetic linkage map and locate quantitative trait loci related to salt resistance. A zombi pea F2 population (159 individuals) developed from a cross between the salt-resistant wild zombi pea accession JP235908 (var. ovata; female parent) and the salt-susceptible cultivated zombi pea accession TVNu240 (var. macrosperma; male parent) was genotyped with simple sequence repeat (SSR) and restriction site-associated DNA sequencing (RAD-seq) markers. A genetic linkage map with 10 linkage groups (LGs) was constructed based on 379 markers (136 SSR and 243 RAD-seq markers). The map spanned 793.25 cM, with a mean distance between adjacent markers of 2.14 cM. A comparative genome analysis revealed high macro-synteny between zombi pea and mung bean/adzuki bean, although several chromosomal translocations likely occurred in zombi pea. The salt tolerance of the F2:3 population was evaluated at the seedling stage under hydroponic conditions. Inclusive composite interval mapping identified three quantitative trait loci (QTLs) (qSaltol1.1 on LG1, qSaltol2.1 on LG2, and qSaltol6.1 on LG6) related to the salt resistance of the F2 population. The qSaltol1.1, qSaltol2.1, and qSaltol6.1 QTLs explained 13.3%, 7.6%, and 8.1% of the salt-resistance phenotypic variance, respectively. A comparative genome analysis revealed that qSaltol1.1 may correspond to the Saltol1.1 QTL conferring salt tolerance in beach cowpea [Vigna marina (Burm.) Merr.], which is a halophytic species. Moreover, two genes encoding a plasma membrane H+-ATPase and a gene encoding a cation/proton exchanger may contribute to the salt resistance of zombi pea and beach cowpea. These findings may be relevant for the breeding of salt-resistant zombi pea plants.