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Gene editing technologies, particularly CRISPR-Cas9, have revolutionized agriculture by offering precise and efficient tools to enhance crop production. The vegetatively propagated crops, crucial for global food security, face challenges such as climate change, pests, and limited genetic diversity. CRISPR-Cas9 enables targeted modifications to improve traits like disease resistance, drought tolerance, and nutritional content, thereby boosting productivity and sustainability. Despite its transformative potential, the adoption of gene editing in vegetatively propagated crops is hampered by technical complexities and regulatory frameworks. This review explores recent advancements, challenges, and prospects of gene editing in vegetatively propagated crops, emphasizing strategies to overcome technical barriers and regulatory constraints. Addressing these issues is essential for realizing the full agricultural potential of gene editing and ensuring food security in a changing global climate., Competing Interests: Declaration of competing interest I am writing to declare that there are no conflicts of interest related to this submission. All authors listed have contributed significantly to the research and have approved the final version of the manuscript for submission., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Introduction: Chronic apical periodontitis is a typical inflammatory disease of the oral cavity, the pathology is characterized by an inflammatory reaction with bone defects in the periapical area. Chinese medicine is our traditional medicine, Carbon Dots (CDs) are a new type of nanomaterials. The purpose of this study was to prepare Yam Carbon Dots (YAM-CDs) to investigate the mechanism of action of YAM-CDs on bone differentiation in vivo and in vitro., Methods: We characterized YAM-CDs using transmission electron microscopy (TEM), Fourier Transform Infrared Spectrometer (FTIR), X-Ray Diffraction (XRD) and photoluminescence (PL). CCK-8 assay, Real-time qPCR, and Western Blot were conducted using bone marrow mesenchymal stem cells (BMSCs) to verify that YAM-CDs promote osteoblast differentiation. In addition, we investigated the role of YAM-CDs in promoting bone formation in an inflammatory setting in an in vivo mouse model of cranial defects., Results: The results of TEM and PL showed that the YAM-CDs mostly consisted of the components C1s, O1s, and N1s. Additionally the average sizes of YAM-CDs were 2-6 nm. The quantum yield was 4.44%, with good fluorescence stability and biosafety. Real-time qPCR and Western blot analysis showed that YAM-CDs promoted osteoblast differentiation under an inflammatory environment by regulating expression of histone demethylase 4B (KDM4B). In vivo, results showed that YAM-CDs effectively repaired cranial bone defects in a mouse model and reduced the expression of inflammatory factors under the action of lipopolysaccharides (LPS)., Conclusion: YAM-CDs promoted the proliferation and differentiation of osteoblasts by regulating the expression of KDM4B to repair cranial bone defects in mice under an LPS-induced inflammatory milieu, which will provide a new idea for the treatment of clinical periapical inflammation and other bone defect diseases., Competing Interests: QianYang Chen, Shuo liu and Yuhan Wang share first authorship. The authors report no conflicts of interest in this work., (© 2024 Chen et al.)

The Chinese yam ( Dioscorea polystachya , DP) is promising for the food and pharmaceutical industries due to its nutritional value and pharmaceutical potential. Its proper cultivation is therefore of interest. An insufficient supply of minerals necessary for plant growth can be manifested by discoloration of the leaves. In our earlier study, magnesium deficiency was excluded as a cause. As a follow-up, this work focused on manganese and molybdenum. To quantify both minerals in leaf extracts of DP, analytical methods based on atomic absorption spectrometry (AAS) using the graphite furnace sub-technique were devised. The development revealed that the quantification of manganese works best without using any of the investigated modifiers. The optimized pyrolysis and atomization temperatures were 1300 °C and 1800 °C, respectively. For the analysis of molybdenum, calcium proved to be advantageous as a modifier. The optimum temperatures were 1900 °C and 2800 °C, respectively. Both methods showed satisfactory linearity for analysis. Thus, they were applied to quantify extracts from normal and discolored leaves of DP concerning the two minerals. It was found that discolored leaves had higher manganese levels and a lower molybdenum content. With these results, a potential explanation for the discoloration could be found.

Yam is an important medicinal and edible dual-purpose plant with high economic value. However, nematode damage severely affects its yield and quality. One of the major effects of nematode infestations is the secondary infection of pathogenic bacteria or fungi through entry wounds made by the nematodes. Understanding the response of the symbiotic microbial community of yam plants to nematodes is crucial for controlling such a disease. In this study, we investigated the rhizosphere and how endophytic microbiomes shift after nematode infection during the tuber expansion stage in the Dioscorea opposita Thunb. cultivar Tiegun. Our results revealed that soil depth affected the abundance of nematodes, and the relative number of Meloidogyne incognita was higher in the diseased soil at a depth of 16 to 40 cm than those at a depth of 0 to 15 and 41 to 70 cm. The abundance of and interactions among soil microbiota members were significantly correlated with root-knot nematode (RKN) parasitism at various soil depths. However, the comparison of the microbial α-diversity and composition between healthy and diseased rhizosphere soil showed no difference. Compared with healthy soils, the co-occurrence networks of M. incognita -infested soils included a higher ratio of positive correlations linked to plant health. In addition, we detected a higher abundance of certain taxonomic groups belonging to Chitinophagaceae and Xanthobacteraceae in the rhizosphere of RKN-infested plants. The nematodes, besides causing direct damage to plants, also possess the ability to act synergistically with other pathogens, especially Ramicandelaber and Fusarium , leading to the development of disease complexes. In contrast to soil samples, RKN parasitism specifically had a significant effect on the composition and assembly of the root endophytic microbiota. The RKN colonization impacted a wide variety of endophytic microbiomes, including Pseudomonas , Sphingomonas , Rhizobium , Neocosmospora , and Fusarium . This study revealed the relationship between RKN disease and changes in the rhizosphere and endophytic microbial community, which may provide novel insights that help improve biological management of yam RKNs., Competing Interests: The author(s) declare no conflict of interest.

Yam (Dioscorea) is a tuber crop cultivated for food security, revenue, and medicinal purposes. It has been used to treat diabetes, asthma, diarrhea, and other diseases. The main active ingredients in yam, polysaccharides, are regarded to be the important reason for its widespread applications. Now, a comprehensive review of research developments of yam polysaccharides (YPs) was presented to explore their prospects. We outlined the structural characteristics, biological activities, structure-activity relationships, and potential applications. Around 13 neutral components and 17 acidic components were separated. They exhibited various bioactivities, including immunomodulatory, hypoglycemic, hypolipidemic, antioxidant, gastrointestinal protective, anti-fatigue, and senile disease treatment activities, as well as prebiotic effect. Structure-activity relationships illustrated that unique structural properties, chemical modifications, and carried biopolymers could influence the bioactivities of YPs. The potential applications in medicine, food, and other fields have also been summarized., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This paper systematically investigates the changes in material properties during electrohydrodynamic (EHD) drying, the discharge characteristics of the EHD system as well as the active ingredients, textural properties (hardness, adhesiveness, etc.) and moisture distribution of yam under EHD, air drying and hot air drying were investigated. The results showed that the active particles and the ionized wind generated during the discharge process of the electrohydrodynamic drying device had a significant effect on the drying. Compared to thermal drying, 21 kV drying resulted in the most complete cellular structure, the best internal bound water content as well as textural properties of yam. It played a positive role in the retention of internal nutrients in yam, and the total phenol and allantoin contents were increased by 25.74% and 81.99%, respectively. These results elucidate the advantages of electrohydrodynamic drying in yam drying and provide a reference for the application of EHD in drying., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

These days, easy access to commercially available (poly)phenolic compounds has expanded the scope of potential research beyond the field of chemistry, particularly in the area of their bioactivity. However, the quality of these compounds is often overlooked or not even considered. This issue is illustrated in this study through the example of (dihydro)phenanthrenes, a group of natural products present in yams, as AMP-activated protein kinase (AMPK) activators. A study conducted in our group on a series of compounds, fully characterized using a combination of chemical synthesis, NMR and MS techniques, provided evidence that the conclusions of a previous study were erroneous, likely due to the use of a misidentified commercial compound by its supplier. Furthermore, we demonstrated that additional representatives of the (dihydro)phenanthrene phytochemical classes were able to directly activate AMPK, avoiding the risk of misinterpretation of results based on analysis of a single compound alone.

Yam is a significant staple food and starch source, particularly in tropical and subtropical regions, holding the fourth position among the world's top ten tuber crops. Yam tubers are rich in essential nutrients and a diverse range of beneficial plant compounds, which contribute to their multifaceted beneficial functions. Furthermore, the abundant starch and resistant starch (RS) content in yam can fulfil the market demand for RS. The inherent and modified properties of yam starch and RS make them versatile ingredients for a wide range of food products, with the potential to become one of the most cost-effective raw materials in the food industry. In recent years, research on yam RS has experienced progressive expansion. This article provides a comprehensive summary of the latest research findings on yam starch and its RS, elucidating the feasibility of commercial RS production and the technology's impact on the physical and chemical properties of starch. Yam has emerged as a promising reservoir of tuber starch for sustainable RS production, with thermal, chemical, enzymatic and combination treatments proving to be effective manufacturing procedures for RS. The adaptability of yam RS allows for a wide range of food applications., Competing Interests: Declaration of competing interest We have no known financial or interpersonal conflicts that might have appeared to have an impact on the research presented in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Yam is a major staple food that provides both energy (starch) and bioactive compounds. However, there is a lack of knowledge on its cooking quality. We have determined the cooking quality of five varieties of water yam (among those most appreciated by consumers), when they were steamed or boiled. The yams were grown in two contrasting locations with regard to pedoclimatic conditions., Results: Ratio of length to mean circumference of the tuber, difficulty to peel, cooking time, color attributes, hardness of steamed pulp, and dry matter (DM) and starch contents significantly varied among varieties. Cooking time and hardness of the cooked pulp, either steamed or boiled, were higher for tubers grown at the drier location, with vertisols, than at the rainy one, with a ferralitic soil. The raw pulp was richer in starch at the rainy location. We found no correlation between either textural properties or DM and the cooking time. A slight (r = 0.44) but significant correlation was recorded between the DM of the raw pulp and the hardness of the steamed product., Conclusion: We propose a comprehensive multicriteria approach for determination of yam cooking quality, textural properties, color attributes and chemical composition, along with varietal and environmental influences. This approach takes into consideration the complexity of food quality, allows a better understanding of its determinants and provides a basis for useful guidelines for breeders. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Background: Consumers' preferences for food crops are guided by quality attributes. This study aimed at deciphering the genetic basis of quality traits, especially tuber flesh color (FC) and oxidative browning (OB) in Dioscorea alata, based on the genome-wide association studies (GWAS) approach. The D. alata panel was planted at two locations in Guadeloupe. At harvest, the FC was scored visually as white, cream, or purple on longitudinally sliced mature tubers. The OB was scored visually as the presence or absence of browning after 15 min of exposure of the sliced samples to ambient air., Results: Phenotypic characterization for FC and OB of a diverse panel of D. alata genotypes highlighted significant variation within the panel and across two locations. The genotypes within the panel displayed a weak structure and could be classified into three subpopulations. GWAS identified 14 and 4 significant associations for tuber FC and OB, respectively, with phenotypic variance, explained values ranging from 7.18% to 18.04%. Allele segregation analysis at the significantly associated loci highlighted the favorable alleles for the desired traits, i.e., white FC and no OB. A total of 24 putative candidate genes were identified around the significant signals. A comparative analysis with previously reported quantitative trait loci indicated that numerous genomic regions control these traits in D. alata., Conclusion: Our study provides important insights into the genetic control of tuber FC and OB in D. alata. The major and stable loci can be further utilized to improve selection in breeding programs for developing new cultivars with enhanced tuber quality. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Phenotyping yam ( Dioscorea spp.) germplasm for resistance to parasitic nematodes is hampered by the lack of an efficient screening method. In this study, we developed a new method using rooted yam vine cuttings and yam plantlets generated from semi-autotrophic hydroponics (SAHs) propagation for phenotyping yam genotypes for nematode resistance. The method was evaluated using 26 genotypes of D. rotundata for their reaction to Scutellonema bradys and four root-knot nematode species, Meloidogyne arenaria , M. enterolobii , M. incognita , and M. javanica . Yam plantlets established in nursery bags filled with steam-sterilized soil were used for screening against single nematode species. Plants were inoculated four weeks after planting and assessed for nematode damage eight weeks later. A severity rating scale was used to classify genotypes as resistant, tolerant, or susceptible determine based on the nematode feeding damage on tubers and the rate of nematode multiplication in the roots of inoculated plants. The results demonstrated putative resistance and tolerance against S. bradys in 58% of the genotypes and 88%, 65%, 65%, and 58% against M. arenaria , M. javanica , M. incognita , and M. enterolobii , respectively. The method is rapid, flexible, and seasonally independent, permitting year-round screening under controlled conditions. This method increases the throughput and speed of phenotyping and improves the selection process.

Background: Kponan is the most popular yam (Dioscorea cayenensis-rotundata) variety in Côte d'Ivoire. Unfortunately, losses due to rotting during storage do not ensure a regular supply to markets. This study aimed to identify the impacts of cultivation and storage practices in the main production areas on physical, cooking and sensory characteristics of Kponan. To this end, yams grown in Bondoukou were stored in straw huts, those grown in Bouna in pits and those grown in Kouassi-Kouassikro in the open air, according to the practices of each producer., Results: Findings showed that yams grown in Kouassi-Kouassikro and stored in the open air recorded the highest rot rate (58.09%) compared to the rot rate of yams grown and stored in pits in Bouna (26.67%) and those grown and stored in straw huts in Bondoukou (53.34%). However, the weight losses were respectively 10.47% (Bouna), 28.57% (Kouassi-Kouassikro) and 36.19% (Bondoukou). Loss rates varied significantly from 43.80% (pits) to 100% (huts and open air). Furthermore, the browning indices were higher for yams grown in Kouassi-Kouassikro and freshly harvested (26.09) compared to the browning index recorded for yams grown and freshly harvested in Bouna (23.43) and in Bondoukou (24.73). Concerning the hardness of yams, it decreased during storage for yams grown and stored in pits in Bouna (38.94 to 25.20 N) and for those grown and stored in straw huts in Bondoukou (39. 39 to 26.42 N)., Conclusion: The shelf life and culinary and sensory characteristics of Kponan depend on the cultivation and storage practices of each producer. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

Yam ( Dioscorea spp.) is a staple food crop with cultural, nutritional and economic significance for millions of small-scale farmers in sub-Saharan Africa. While various virus-like symptoms such as mosaic and chlorosis are frequently observed in yam fields in Ethiopia, little information is available on the prevalence, distribution, and molecular characteristics of viruses causing these symptoms. The aim of this study was to investigate the incidence and distribution of yam viruses and determine the primary cause of yam mosaic diseases (YMD) in Ethiopia. Both symptomatic (n = 280) and asymptomatic (n = 110) yam leaf samples were collected and tested for potyviruses using ACP-ELISA. In addition, the symptomatic leaf samples were screened for yam mosaic virus (YMV), yam mild mosaic virus (YMMV), and cucumber mosaic virus (CMV) by DAS-ELISA. Subsequently, total RNA was extracted from 130 leaf samples comprising 94 symptomatic and 36 asymptomatic samples representing the different study areas. The representative RT-PCR amplicons (n = 6) were Sanger sequenced. The ACP-ELISA and DAS-ELISA results showed 9.2%, and 12.9% YMV infection, respectively, while the RT-PCR analysis showed 28.5% YMV positivity rate. Both CMV and YMMV were not detected in any of the samples tested. Thus, YMV is confirmed as the primary cause of YMD in Ethiopia. YMV isolates from Ethiopia shared 92-93% nucleotide identity among themselves and 85-99% with other YMV isolates from the GenBank. Phylogenetic analysis revealed that YMV isolates from Ethiopia, South America, and west-central Africa have the most recent common ancestor, while isolates from China and Japan are clustered as sister groups. This study enhances our understanding of YMV's genetic diversity and provides valuable information regarding the first report of YMV in Ethiopia., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

This experiment aimed to establish a green, simple and highly sensitive method (supercritical fluid chromatography (SFC) coupled with ion mobility quadrupole time-of-flight mass spectrometry (IM-Q-TOF/MS)) for the detection of multiple pesticides in foods. During the experiments, several important SFC parameters, such as stationary phase, modifier, make-up solution, back-temperature and back-pressure were optimized. Here, single-field collision cross section (CCS) values and multifield CCS values of 20 pesticides were examined by IM-Q-TOF/MS as highly specific parameters with excellent experimental precision. In addition, based on accurate mass matching and fragment ion comparison, mass fragments were obtained by IM-Q-TOF/MS, which elucidated the regularities of compound structure and characteristic fragment ions. Under the optimized conditions, satisfactory linearity (R 2  ≥ 0.9989) and recoveries (79.60 % to 112.97 %) were obtained. The intra- and interday precisions were favorable, with RSDs lower than 4.91 and 7.65 %, respectively. Additionally, the method showed low limits of detection (0.1-8.8 ng/mL). The proposed method has been successfully applied to the highly sensitive detection of phenylurea herbicide, triazine herbicides, organophosphorus pesticide, pyrethroid insecticide and acaricide in yam and potato., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The Chinese yam ( Dioscorea polystachya , DP) is known for the nutritional value of its tuber. Nevertheless, DP also has promising pharmacological properties. Compared with the tuber, the leaves of DP are still very little studied. However, it may be possible to draw conclusions about the plant quality based on the coloration of the leaves. Magnesium, as a component of chlorophyll, seems to play a role. Therefore, the aim of this research work was to develop an atomic absorption spectrometry-based method for the analysis of magnesium (285.2125 nm) in leaf extracts of DP following the graphite furnace sub-technique. The optimization of the pyrolysis and atomization temperatures resulted in 1500 °C and 1800 °C, respectively. The general presence of flavonoids in the extracts was detected and could explain the high pyrolysis temperature due to the potential complexation of magnesium. The elaborated method had linearity in a range of 1-10 µg L -1 (R 2 = 0.9975). The limits of detection and quantification amounted to 0.23 µg L -1 and 2.00 µg L -1 , respectively. The characteristic mass was 0.027 pg, and the recovery was 96.7-102.0%. Finally, the method was applied to extracts prepared from differently colored leaves of DP. Similar magnesium contents were obtained for extracts made of dried and fresh leaves. It is often assumed that the yellowing of the leaves is associated with reduced magnesium content. However, the results indicated that yellow leaves are not due to lower magnesium levels. This stimulates the future analysis of DP leaves considering other essential minerals such as molybdenum or manganese.

This study describes what did and did not work in the prioritization of preferred traits within the value chain of yam and associated food products (boiled and pounded yam) in Nigeria. Demand-led breeding protocols have enhanced participatory methods along gender lines to increase the clarity of information on the yam traits preferred by farmers and other end users. Drawing on the experience of the cross-cutting gender team at the National Root Crops Research Institute (NRCRI), Umudike, and partners, this study documents the successes and constraints in the use of gender-inclusive approaches for effective breeding. Methods in our gender studies involve critical assessment of the distinction between quantitative and qualitative research, with particular attention to measurement. Various techniques for data collection, such as interviews, observation, and archival studies, are assessed to locate their potential for constructing successful research projects. The methods used include participatory varietal selection, participatory plant breeding, focused discussions with farmer groups, value chain mapping, G+ tools, trait preferences (processing and consumption), triangulation of multi-disciplinary datasets, and social survey research. Yam production in southeast Nigeria is dominated by men, while women are the main processors. Gendered power play, access to resources, and decision-making have been found to constrain women's participation in yam production (and in yam research). Sex disaggregation was applied within the value chain studies to capture the complementarity and differences in the perceptions of women and men. The methods used facilitated the development and release to farmers in 2023 of three improved yam varieties with consumer-preferred characteristics such as high yield, high dry matter content, white tubers, and good boiling and pounding capability. The success stories also show that effective communication and cooperation within the gender cross-cutting team and farmer groups are important for better results. When gender specialists, food scientists, and breeders work together, innovations are created, challenges are overcome, and information is shared., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer OU declared a past collaboration with the authors BO, OO, TM to the handling editor., (Copyright © 2023 Okoye, Ofoeze, Ejechi, Onwuka, Nwafor, Onyemauwa, Ukeje, Eluagu, Obidiegwu, Olaosebikan and Madu.)

Proteases such as trypsins in the gut of Spodoptera frugiperda are responsible for breaking down dietary proteins into amino acids necessary for insect growth and development. In this study, we characterized the insecticidal potential of dioscorin, the storage protein of yam (Dioscorea alata), using molecular docking and molecular dynamics simulations to determine the interactions between trypsin enzymes and the protein inhibitor dioscorin. To achieve this, we used the three-dimensional structures of the trypsin-like digestive enzymes of S. frugiperda, a pest of corn and cotton, as receptors or target molecules. We performed protein-protein docking using Cluspro software, estimation of the binding free energy, and information on the dynamic and time-dependent behavior of dioscorin-trypsin complexes using the NAMD package. Our computational analysis showed that dioscorin can bind to the digestive trypsins of S. frugiperda, as confirmed by the affinity energy values (-1022.4 to -1236.9), stability of the complexes during the simulation trajectory, and binding free energy values between -57.3 and -66.9 kcal/mol. Additionally, dioscorin uses two reactive sites to bind trypsin, but the largest contribution to the interaction energy is made by amino acid residues between amino acid backbone positions 8-14 by hydrogen bonds, hydrophobic, and Van der Waals (VdW) interactions. VdW is the energy that makes the greatest contribution to the binding energy. Collectively, our findings demonstrate, for the first time, the binding capacity of the yam protein dioscorin to the digestive trypsin of S. frugiperda. These promising results suggest a possible bioinsecticide action of dioscorin., (© 2023 Wiley Periodicals LLC.)

Yam ( Dioscorea spp.) productivity is constrained significantly by the lack of a formal seed system. Vegetative propagation, through tuber setts as 'seed' yams, encourages the recycling of virus-infected planting materials, contributing to high virus incidence and yield losses. Efforts are ongoing to increase the production of high-quality seed yams in a formal seed system to reduce virus-induced yield losses and enhance the crop's productivity and food security. Specific and sensitive diagnostic tests are imperative to prevent the multiplication of virus-infected materials contributing to a sustainable seed yam certification system. During routine indexing of yam accessions, discrepancies were observed between the results obtained from the reverse transcription loop-mediated isothermal amplification (RT-LAMP) test and those from reverse transcription polymerase chain reaction (RT-PCR); RT-LAMP failed to detect Yam mosaic virus (YMV) in some samples that tested positive by RT-PCR. This prompted the design of a new set of LAMP primers, YMV1-OPT primers. These primers detected as little as 0.1 fg/µL of purified RNA obtained from a YMV-infected plant, a sensitivity equivalent to that obtained with RT-PCR. RT-LAMP using YMV1-OPT primers is recommended for all future virus-indexing of seed yams for YMV, offering a rapid, sensitive, and cost-effective approach.

BBX proteins play important roles in all of the major light-regulated developmental processes. However, no systematic analysis of BBX gene family regarding the regulation of photoperiodic microtuber formation has been previously performed in yam. In this study, a systematic analysis on the BBX gene family was conducted in three yam species, with the results, indicating that this gene plays a role in regulating photoperiodic microtuber formation. These analyses included identification the BBX gene family in three yam species, their evolutionary relationships, conserved domains, motifs, gene structure, cis-acting elements, and expressional patterns. Based on these analyses, DoBBX2/DoCOL5 and DoBBX8/DoCOL8 showing the most opposite pattern of expression during microtuber formation were selected as candidate genes for further investigation. Gene expression analysis showed DoBBX2/DoCOL5 and DoBBX8/DoCOL8 were highest expressed in leaves and exhibited photoperiod responsive expression patterns. Besides, the overexpression of DoBBX2/DoCOL5 and DoBBX8/DoCOL8 in potato accelerated tuber formation under short-day (SD) conditions, whereas only the overexpression of DoBBX8/DoCOL8 enhanced the accelerating effect of dark conditions on tuber induction. Tuber number was increased in DoBBX8/DoCOL8 overexpressing plants under dark, as well as in DoBBX2/DoCOL5 overexpressing plants under SD. Overall, the data generated in this study may form the basis of future functional characterizations of BBX genes in yam, especially regarding their regulation of microtuber formation via the photoperiodic response pathway., (© 2023. The Author(s).)

Allantoin is an abundant component of yams and has been known as a skin protectant due to its pharmacological activities. In previous methods for allantoin determination using high-performance liquid chromatography (HPLC), the separation was unsatisfactory. We herein developed a 1 H quantitative nuclear magnetic resonance (qNMR) method for quantification of allantoin in the flesh and peel of yams. The method was carried out based on the relative ratio of signals integration of allantoin to a certain amount of the internal standard dimethyl sulfone (DMSO 2 ) and validated in terms of specificity, linearity (range 62.5-2000 μg/ml), sensitivity (limit of detection (LOD) and quantification (LOQ) 4.63 and 14.03 μg/ml, respectively), precision (RSD% 0.02-0.26), and recovery (86.35-92.11%). The method was then applied for the evaluation of allantoin in flesh and peel extracts of four different yams cultivated in Korea.

Anthracnose disease caused by Colletotrichum gloeosporioides is one of the devastating diseases of yams ( Dioscorea sp.) worldwide. In this study, we aimed to isolate endophytic actinobacteria from yam plants and to evaluate their potential for the control of yam anthracnose based on bioassays and genomic analyses. A total of 116 endophytic actinomycete strains were isolated from the surface-sterilized yam tissues from a yam orchard in Hainan Province, China. In total, 23 isolates showed antagonistic activity against C. gloeosporioides . An endophytic actinomycete, designated HNM0140 T , which exhibited strong antifungal activities, multiple biocontrol, and plant growth-promoting (PGP) traits was subsequently selected to colonize in the tissue-cultured seedlings of yam and was tested for its in vivo biocontrol potential on yam anthracnose. The results showed that treatment with strain HNM0140 T markedly reduced the severity and incidence of yam anthracnose under greenhouse conditions. Morphological and chemotaxonomic analyses showed that strain HNM0140 T was assigned to the genus Streptomyces . Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain HNM0140 T formed a separate cluster together with Streptomyces lydicus ATCC 25470 T (99.45%), Streptomyces chattanoogensis NRRL ISP-5002 T (99.45%), and Streptomyces kronopolitis NEAU-ML8 T (98.97%). The phylogenomic tree also showed that strain HNM0140 T stably clustered with Streptomyces lydicus ATCC 25470 T . The ANI and dDDH between strain HNM0140 T and its closest related-type species were well below the recommended thresholds for species demarcation. Hence, based on the phylogenetic, genomic, and phenotypic analyses, strain HNM0140 T should represent a new streptomycete species named Streptomyces endophytica sp. nov. Genomic analysis revealed that strain HNM0140 T harbored 18 putative BGCs for secondary metabolites, some PGP-related genes, and several genes coding for antifungal enzymes. The presented results indicated that strain HNM0140 T was a promising biocontrol agent for yam anthracnose., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhou, Zhou, Li, Wu, Xu, Xia, Huang and Huang.)

Gender-disaggregated sensory evaluation has become an essential element that could enhance breeding activities by increasing the adoption of new varieties. The effect of age, sex and geographical location on descriptor preferences for boiled and pounded yam were studied using descriptive and consumer testing. Attributes with definitions and measurement scales were used to generate lexicons for boiled and pounded yam. Analytical tools employed for the inferential statistics were the independent t -test, analysis of variance, Kruskal-Wallis test, Mann-Whitney test and relative importance index (RII). Descriptive testing showed that all the D. rotundata varieties were good for boiling and pounding. The D. alata varieties afase soanyinto and afase biri were most liked, while afase pa and ahodenfo were disliked. Age had no significant effect on descriptor preferences. Being a female or male, however, influenced preferences for pounded yam descriptors such as mouldability, lumpiness and colour. The RII for the D. rotundata varieties (0.22-0.28) showed that they are all good varieties for boiling and pounding. The local D. alata varieties were still highly acceptable compared the new CRI varieties due to the aroma. Rural consumers preferred all the descriptors of boiled D. rotundata than urban consumers, whereas urban consumers liked the pounded yam varieties better than the rural consumers. Availability of the new yam varieties on local markets could therefore increase consumption and improve adoption.

Background: Coffee bean weevil ( Araecerus fasciculatus DeGeer) (Coleoptera: Anthribidae) infestation is a major challenge affecting processed, dried, and stored foods globally. However, the growth performance of this insect pest in processed and stored cassava, plantain, yam, and cocoyam is poorly understood. Resolving this will guide future biotechnological efforts on these food products. In the study, the susceptibility rate of the processed and stored product of cassava, yam, cocoyam, and plantain to the growth performance of the coffee bean weevil at laboratory conditions (20 ± 5 °C and 70 ± 5% R.H.) was investigated. The anti-nutritional (phytate, alkaloids, saponin, tannin, and oxalate) contents of this stored food were used to characterize the survival rate of A. fasciculatus. The study was carried out for 6 months between December 2012 and May 2013., Results: Results show that the adult longevity, growth, and feeding of the adult A. fasciculatus decrease in order from Cassava, Plantain, Yam to Cocoyam. Cocoyam has the highest tannin, alkaloid, and phytate values, which are possible factors that inhibited the growth of the larvae, pupae, and adults' A. fasciculatus . The highest weight loss occurred in cassava followed by plantain. The anti-nutritional factors determine the hatchability of the A. fasciculatus eggs and throughout its development stages. This study revealed that processed and stored products (e.g., cocoyam) with high anti-nutritional factors can survive A. fasciculatus under prolonged storage., Conclusions: From this study, it is observed that high anti-nutritional compounds in the stored food products inhibit the growth of Araecerus fasciculatus , especially in cocoyam. The result is important in food security and management in developing countries where food insecurity has become a major challenge., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s) 2023.)

β-amylase (BAM) plays an important role in plant development and response to abiotic stresses. In this study, 5 DoBAM members were identified in yam ( Dioscorea opposita Thunb.). A novel β-amylase gene BAM1 , (named DoBAM1 ), was isolated from yam varieties Bikeqi and Dahechangyu. The open reading frame (ORF) of DoBAM1 is 2806 bp and encodes 543 amino acids. Subcellular localization analysis indicates that DoBAM1 localizes to the cell membrane and cytoplasm. In the yam variety Dahechangyu, the starch content, β-amylase activity, and expression of DoBAM1 were characterized and found to all be higher than in Bikeqi. DoBAM1 overexpression in tobacco is shown to promote the accumulation of soluble sugar and chlorophyll content and to increase the activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and β-amylase. Under cold treatment, we observed the induced upregulation of DoBAM1 and lower starch content and malondialdehyde (MDA) accumulation than in WT plants. In conclusion, these results demonstrate that DoBAM1 overexpression plays an advanced role in cold tolerance, at least in part by raising the levels of soluble sugars that are capable of acting as osmolytes or antioxidants.

A rhizomatous Dioscorea crop 'Edo-dokoro' was described in old records of Japan, but its botanical identity has not been characterized. We found that Edo-dokoro is still produced by four farmers in Tohoku-machi of the Aomori prefecture, Japan. The rhizomes of Edo-dokoro are a delicacy to the local people and are sold in the markets. Morphological characters of Edo-dokoro suggest its hybrid origin between the two species, Dioscorea tokoro and Dioscorea tenuipes. Genome analysis revealed that Edo-dokoro likely originated by hybridization of a male D. tokoro to a female D. tenuipes, followed by a backcross with a male plant of D. tokoro. Edo-dokoro is a typical minor crop possibly maintained for more than 300 years but now almost forgotten by the public. We hypothesize that there are many such uncharacterized genetic heritages passed over generations by small-scale farmers that await serious scientific investigation for future use and improvement by using modern genomics information., (© The Author(s) 2022. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.)

Consumption of high Glycemic Index (GI) foods is a risk factor for increasing prevalence of diabetes mellitus (DM). The extent of variation in starch digestibility and GI of Yam varieties and products is not yet fully understood. This study was therefore designed to evaluate in vitro and in vivo Glycemic Index properties of commonly consumed products prepared from varieties of White Yam. Four products (boiled, fried, pounded yam, and Amala ) were prepared from 5 common varieties of Yam and evaluated for Digestible Starch (DS) and Resistant Starch (RS). Based on results, two products-pounded yam and Amala -were processed from three of the most popular varieties. Analysis of Rapidly Digestible Starch (RDS), Slowly Digestible Starch (SDS), and estimated in vitro GI (eGI) were then carried out in this stage. Glycemic Index (GI) of these products consumed by apparently healthy young adults were also determined. Variety Amula had highest DS in Amala (19.1/100 g) and pounded Yam (20.4/100 g) while variety Alumaco had highest RS in all the products (2.9-3.3/100 g). When compared with RS in its raw tuber, RS of Alumaco generally increased after processing. Variety Alumaco had lowest RDS in Amala (0.6/100 g) and pounded yam (0.3/100 g) while eGI was lowest in Alumaco made into Amala (53) and pounded yam (48). Assessment of GI resulted in high GI for all products across each variety. Irrespective of variety, processing Yam into Amala released RDS fraction faster when compared with pounded yam. Generally, even though the products are considered as having high GI, Amala raised eGI and GI faster than Pounded yam. Variety- Alumaco particularly showed favorable properties applicable to dietary management of diabetes. Exploring more processing methods and genetic diversity is recommended., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Eyinla, Sanusi and Maziya-Dixon.)

Yam (Dioscorea opposita Thunb.) is cultivated mainly as a functional food and for nutritional and medicinal purposes in China (1). It is propagated through tubers and this facilitates the spread and accumulation of viruses in the crop, eventually leading to yield losses (2). At present, different virus species belonging to the genera Aureusvirus, Badnavirus, Carlavirus, Comovirus, Cucumovirus, Fabavirus, Macluravirus, Potexvirus and Potyvirus have been reported in yams (3) and fifteen viruses in these genera have been detected in China. In July 2020, a survey of viral diseases on yam was conducted in plantations of Wenxian and Mengzhou counties in Henan Province, China. Fifty-four leaf samples of Dioscorea opposite showing mosaic and leaf discoloration (Supplementary Fig1) were collected from eight fields (five to ten plants per field). These leaf samples were ground in liquid nitrogen and total RNA was extracted from a portion of the mixed powder using RNAprep Pure Plant Plus Kit (TIANGEN Biotech, Beijing, China). A cDNA library was constructed using NEBNext Ultra RNA Library Prep Kit for Illumina (NEB, USA) after ribosomal RNA depletion using Ribo-off rRNA Depletion Kit (Vazyme Biotech, Nanjing, China), and sequenced on the Illumina NovaSeq 6000 system at the Berry Genomics Corporation (Beijing, China). A total of 87,075 contigs (>200 bp) were generated from de novo assembly (CLC Genomic Workbench 10.0) from a total of 34,656,172 paired-end reads. After BLASTn analysis, three contigs with the length of 1009, 1340 and 1859 nucleotides shared 96.33%, 96.72% and 96.29% nt identity respectively with youcai mosaic virus SX isolate, a tobamovirus (YoMV GenBank accession no. JX422022). In addition to YoMV, broad bean wild virus 2 and yam latent virus were also identified, which had previously been reported in yams in China. To confirm the NGS result, total RNAs were extracted from fifty-four above-mentioned samples and RT-PCR was carried out to amplify a 528 bp fragment of the coat protein (CP) of YoMV by using a pair of specific primers CP gene. PCR products with expected size were obtained from 26 out of 54 samples, and seventeen amplicons of YoMV-CP were sequenced (accession nos. ON052726 to ON052742). The nt sequence identities of CP gene among these seventeen isolates were 99.6%-100%. Furthermore, the near-full-length genomic sequence of YoMV-Do41 isolate was obtained from sample 41 by RT-PCR amplification of four overlapping fragments using the following primer pairs: YoMV-15F/YoMV-1910R, YoMV-1770F/YoMV-3750R, YoMV-3645F/YoMV-5404R and YoMV-4921F/YoMV-6280R (Supplementary Table1). The YoMV-Do41 isolate was 6, 274 nt in length (accession no. ON149803) and shared 89.65% and 97.31% nt identities to As1-2 isolate (GenBank accession no. MW307290) and to SX isolate (accession no. JX422022), respectively.To the best of our knowledge, this is the first report of YoMV infecting yam in China. YoMV has a wide host range including genera Impatiens, Rehmannia, Brassica, Chelidonium, Trifolium, Crossandro, Alstroemeria, Stellaria. This study will serve as an important reference for the host range of YoMV. According to the detection rate infections with YoMV in yam are common in these producing regions. Further studies will be required to determine the infection rate in other producing regions and the potential threat posed by YoMV on yam production should be considered.

Phenanthrenes are bioactive phenolic compounds found in genus Dioscorea , in which they are distributed more in peel than in flesh. Recent studies on phenanthrenes from Dioscorea sp. peels have revealed the potential for valuable biomaterials. Herein, an analytical method using high-performance liquid chromatography (HPLC) for quantitation of bioactive phenanthrenes was developed and validated. The calibration curves were obtained using the phenanthrenes (1-3) previously isolated from Dioscorea batatas concentrations in the range of 0.625-20.00 μg/ml with a satisfactory coefficient of determination (R 2 ) of 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) values of the isolated phenanthrenes ranged from 0.78-0.89 and 2.38-2.71 μg/ml, respectively. The intraday and interday precision ranged from 0.25-7.58%. The recoveries of the isolated phenanthrenes were from 95 to 100% at concentrations of 1.25, 2.5, and 5.0 μg/ml. Additionally, phenanthrenes (1-3) were found in all investigated peel extracts. Hence, the developed method was encouraging for the quantitative analysis of phenanthrenes in genus Dioscorea .

Yam ( Dioscorea spp. ) and its associated extracts have been shown to possess a variety of biological activities and identified as beneficial in the control of glycaemia in patients with type II diabetes mellitus (T2DM). The objective was to conduct a systematic search of the literature to investigate whether yam and its extract can improve glycaemia and whether the consumption of yam could be beneficial for managing T2DM. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and the Population, Invention, Comparison and Outcome framework, three databases (PubMed, Scopus and Web of Science) were searched using a key term strategy. Strict inclusion criteria were employed to identify all relevant and available studies. The quality of these studies was assessed using SYRCLE's Risk of Bias tool. Ten studies were included, and all studies consisted of findings from rodent models of diabetes, including animals consuming high fat diets or genetic models of diabetes. All ten studies showed that the consumption of yam and/or its extracts (containing dioscin, dioscorin, diosgenin, DA-9801/02 or Chinese yam polysaccharides) improved glycaemia. These included improvements in fasting blood glucose and reductions in glucose and increase in insulin levels following a glucose tolerance test. Furthermore, significant changes in body weight and adiposity were observed in nine studies, these included improvements in lipid biomarkers in four and reductions in inflammatory markers in one. The current work indicates that the consumption of yam or its extracts can be beneficial for improving blood glucose; however, the molecular mechanism for these effects remains largely unknown. Future trials on human subjects are warranted.

Viruses are a major constraint for yam production worldwide. They hamper the conservation, movement, and exchange of yam germplasm and are a threat to food security in tropical and subtropical areas of Africa and the Pacific where yam is a staple food and a source of income. However, the biology and impact of yam viruses remains largely unknown. This review summarizes current knowledge on yam viruses and emphasizes gaps that exist in the knowledge of the biology of these viruses, their diagnosis, and their impact on production. It provides essential information to inform the implementation of more effective virus control strategies.

Improving the effectiveness of breeding programs could be achieved by breeding for consumers' preferences. The relationship between gender and consumer preferences for yam was studied using purposeful sampling for key informants, focus group discussions (FGDs), and individual interviews. Data from qualitative interviews were transcribed and quantitative data analyzed using SPSS (version 20). Cramer's V (Phi) and logistic regressions were used to explain the observations. Males prioritized income-generating varieties over females, while females ranked tuber morphological characteristics high. Sex-based preference for yams showed that moldability and sweet taste are preferred by both females and males. Moderately hard boiled yams and shelf stable food products are liked by males, whereas aroma is rated highly by females. Males described yams that have a longer digestion time as "heavy" and preferred such varieties. Watery tubers and tubers not turning brown are important characteristics during processing. The Phi of 0.157 and 0.163 for sex and ethnic groups show moderate to strong associations between choices for descriptors by females, males, and various ethnic groups. These findings imply that gender disaggregation of information on preference for yam quality descriptors should be considered in future yam breeding programs as it may improve adoption rate and enhance food security., Competing Interests: All authors have no conflict of interest to declare., (© 2022 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)

Plant-derived nonprecious metal catalysts are considered one of the promising candidates of platinum for oxygen reduction reaction (ORR). In this work, the typical microscopic morphology of fresh green crop yam is first detected by cryoscanning electronic microscopy. Using the green and widely sourced yam with spherical starch in nature as a precursor, well-defined spherical carbons are prepared via hypersaline-assisted hydrothermal carbonization and NH 3 activation, featuring a high heteroatom doping level and a hierarchical porous structure. Experimental results and density functional theory (DFT) calculations reveal that diverse off-plane Fe-N x -C y ensembles on the spherical carbons trigger the high performance that exceeds state-of-art Pt/C and most reported carbon catalysts toward ORR in a KOH solution. The increased charge density and the bond length of Fe coordinated in the sites should be responsible for the significantly improved property. The easily editing of off-plane active sites from the simple carbon morphology may shed light on optimizing nonprecious carbons as next-generation catalysts for ORR.

Viruses of the genus Badnavirus (family Caulimoviridae ) are double-stranded DNA-reverse transcribing (dsDNA-RT) plant viruses and have emerged as serious pathogens of tropical and temperate crops globally. Endogenous badnaviral sequences are found integrated in the genomes of several economically important plant species. Infection due to activation of replication-competent integrated copies of the genera Badnavirus , Petuvirus and Cavemovirus has been described. Such endogenous badnaviral elements pose challenges to the development of nucleic acid-based diagnostic methods for episomal virus infections and decisions on health certification for international movement of germplasm and seed. One major food security crop affected is yam ( Dioscorea spp.). A diverse range of Dioscorea bacilliform viruses (DBVs), and endogenous DBV (eDBV) sequences have been found to be widespread in yams cultivated in West Africa and other parts of the world. This study outlines the development of multiplex PCR-dependent denaturing gradient gel electrophoresis (PCR-DGGE) to assist in the detection and analysis of eDBVs, through the example of analysing yam germplasm from Nigeria and Ghana. Primers targeting the three most prevalent DBV monophyletic species groups in West Africa were designed to improve DGGE resolution of complex eDBV sequence fingerprints. Multiplex PCR-DGGE with the addition of a tailor-made DGGE sequence marker enables rapid comparison of endogenous badnaviral sequence diversity across germplasm, as illustrated in this study for eDBV diversity in yam., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Silva, Bömer, Turaki, Nkere, Kumar and Seal.)

Abstract: In this work, the effect of the modifications (annealing, acid hydrolysis and citric acid substitution) on starch granule size frequency distribution, Fourier Transform Infrared (FTIR) spectra, and adsorption isotherm of starches of four yam cultivars were studied. The native and modified white yam, water yam, and yellow yam starches had a normal distribution frequency profile for the granule sizes, which were similar among the cultivars. In contrast, the native and modified bitter yam starch granules were not normally distributed. The modifications resulted in a left shift in normal distribution frequency profiles for the granules sizes of the white, water and yellow yam starches due to broadening of the range of granule sizes. The FTIR spectra revealed that additional bands at 1726.95-1729.49 cm -1 were introduced due to citric acid modification of the yam starches. The modifications also caused weakening of the FTIR band representing -CH 2 and -OH stretching at 2927.85-2932.94 cm -1 and 3259.42-3437.33 cm -1 , respectively. The native, annealed and acid hydrolyzed yam starches all had similar adsorption isotherms at 28 °C. On the other hand, the citric acid-substituted yam starches showed a different adsorption isotherm, because they had significantly higher equilibrium moisture content at water activity ( a ) above 0.9. All the adsorption isotherms were type III, J-shaped isotherms. The adsorption isotherms data of the yam starches fitted best to the Guggenheim-Anderson-De Boer (GAB) model. The GAB model monomolecular moisture content ranged between 0.0165 and 0.0597 g/g db. w ) above 0.9. All the adsorption isotherms were type III, J-shaped isotherms. The adsorption isotherms data of the yam starches fitted best to the Guggenheim-Anderson-De Boer (GAB) model. The GAB model monomolecular moisture content ranged between 0.0165 and 0.0597 g/g db., Article Highlights: Native and modified yam starches' granules size were normally distributed except bitter yam starchFTIR revealed additional bands and molecular rearrangements were introduced due to modificationsAdsorption isotherms revealed type III, GAB-model isotherms with low monomolecular moisture., Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05200-7., Competing Interests: Conflict of interestThe authors declare that they have no competing interests., (© Association of Food Scientists & Technologists (India) 2021.)

Biochemical characterisation of germplasm collections and crop wild relatives (CWRs) facilitates the assessment of biological potential and the selection of breeding lines for crop improvement. Data from the biochemical characterisation of staple root, tuber and banana (RTB) crops, i.e. banana ( Musa spp.), cassava ( Manihot esculenta ), potato ( Solanum tuberosum ), sweet potato ( Ipomoea batatas ) and yam ( Dioscorea spp .), using a metabolomics approach is presented. The data support the previously published research article "Metabolite database for root, tuber, and banana crops to facilitate modern breeding in understudied crops" (Price et al., 2020) [1]. Diversity panels for each crop, which included a variety of species, accessions, landraces and CWRs, were characterised. The biochemical profile for potato was based on five elite lines under abiotic stress. Metabolites were extracted from the tissue of foliage and storage organs (tuber, root and banana pulp) via solvent partition. Extracts were analysed via a combination of liquid chromatography - mass spectrometry (LC-MS), gas chromatography (GC)-MS, high pressure liquid chromatography with photodiode array detector (HPLC-PDA) and ultra performance liquid chromatography (UPLC)-PDA. Metabolites were identified by mass spectral matching to in-house libraries comprised from authentic standards and comparison to databases or previously published literature., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 Published by Elsevier Inc.)

There is little information about nematode pests associated with yam in China. Between 2020 and 2021, surveys of yam fields were conducted to investigate the abundance and prevalence of plant-parasitic nematodes in major yam growing areas. A total of 110 bulk soil samples from the yam rhizosphere and 48 yam tubers were collected from seven counties in Jiangxi and Shandong provinces. Standard protocols were used to extract nematodes from soil and tubers and identified at the genus level. In this study, 16 species and 13 nematode genera were recorded. The five most prominent species on the yam rhizosphere according to mean population densities were Pratylenchus coffeae (291/individuals), Meloidogyne (262/individuals), Rotylenchulus reniformis (225/individuals), Merlinius (224/individuals), and Helicotylenchus dihystera (171/individuals). In the tubers, the three most prominent species were Pratylenchus coffeae (415/individuals), Meloidogyne (331/individuals), and Rotylenchulus reniformis (115/individuals). These species were verified with appropriate molecular analysis. The high prevalence of the ectoparasite ( Merlinius spp.) on the rhizosphere of yam also revealed that Merlinius spp. May be more important to yam than previously thought. Morphological and molecular analyses further confirmed the identity of the species as Merlinius brevidens and were characterized for the first time on yam in China. Minor morphometrical differences (slightly longer body and stylet) were observed in Chinese populations of M. brevidens compared to the original description. Additionally, this study reveals that M. brevidens isolated from China showed a higher nucleotide sequence in the ITS region compared to M. brevidens populations from India. This finding provides baseline information on the nematode pest occurrence on yam in China and calls for effective management.

Yam (Dioscorea spp.) anthracnose, caused by Colletotrichum alatae, is the most devastating fungal disease of yam in West Africa, leading to 50%-90% of tuber yield losses in severe cases. In some instances, plants die without producing any tubers or each shoot may produce several small tubers before it dies if the disease strikes early. C. alatae affects all parts of the yam plant at all stages of development, including leaves, stems, tubers, and seeds of yams, and it is highly prevalent in the yam belt region and other yam-producing countries in the world. Traditional methods adopted by farmers to control the disease have not been very successful. Fungicides have also failed to provide long-lasting control. Although conventional breeding and genomics-assisted breeding have been used to develop some level of resistance to anthracnose in Dioscorea alata, the appearance of new and more virulent strains makes the development of improved varieties with broad-spectrum and durable resistance critical. These shortcomings, coupled with interspecific incompatibility, dioecy, polyploidy, poor flowering, and the long breeding cycle of the crop, have prompted researchers to explore biotechnological techniques to complement conventional breeding to speed up crop improvement. Modern biotechnological tools have the potential of producing fungus-resistant cultivars, thereby bypassing the natural bottlenecks of traditional breeding. This article reviews the existing biotechnological strategies and proposes several approaches that could be adopted to develop anthracnose-resistant yam varieties for improved food security in West Africa., (© 2021 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)

A novel bacterium, designated strain Msb3 T , was recently isolated from leaves of the yam family plant Dioscorea bulbifera ( Dioscoreaceae ). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that this strain belonged to the genus Paraburkholderia with Paraburkholderia xenovorans as nearest validly named neighbour taxon (99.3 % sequence similarity towards the P. xenovorans type strain). Earlier genome sequence analysis revealed a genome of 8.35 Mb in size with a G+C content of 62.5 mol%, which was distributed over two chromosomes and three plasmids. Here, we confirm that strain Msb3 T represents a novel Paraburkholderia species. In silico DNA-DNA hybridization and average nucleotide identity (OrthoANIu) analyses towards P. xenovorans LB400 T yielded 58.4 % dDDH and 94.5 % orthoANIu. Phenotypic and metabolic characterization revealed growth at 15 °C on tryptic soy agar, growth in the presence of 1 % NaCl and the lack of assimilation of phenylacetic acid as distinctive features. Together, these data demonstrate that strain Msb3 T represents a novel species of the genus Paraburkholderia, for which we propose the name Paraburkholderia dioscoreae sp. nov. The type strain is Msb3 T (=LMG 31881 T , DSM 111632 T , CECT 30342 T ).

Yams ( Dioscorea spp.) are cultivated and consumed as edible tubers, while their leaves are discarded as waste or burned with negative environmental impact. Herein, the metabolites of two yam species (Danma, DAN; Dunggeunma, DUN), harvested in June, July, and August, were profiled using GC-TOF-MS and UHPLC-LTQ-Orbitrap-MS/MS and the antioxidant activity of the extracts was evaluated to stimulate the utilization of yam leaves as a by-product. We observed that the relative levels of amino acids, organic acids, sugars, and saponins decreased linearly with prolonged harvest time, while fatty acid, phenanthrene, and flavonoid levels gradually increased. Furthermore, the leaf extracts obtained in August exhibited the highest antioxidant activity. To determine the antioxidant-contributing metabolites, OPLS-DA was performed for the leaf metabolites of DAN and DUN leaves harvested in August. Hydroxytyrosol-glucoside, apigenin-rhamnoside, and rutin were more abundant in DUN, while luteolin, phenanthrene derivatives, epicatechin, and kaempferide were relatively higher in DAN and their respective metabolites were positively correlated with the antioxidant activity. Moreover, secondary metabolites were more abundant in the leaves than in the roots, and consequently, the antioxidant activity of the former was also higher. Overall, the potential value of yam leaves as a renewable source of bioactive compounds is proposed.

Taking the main production area of yam in North China Plain as the research area, we analyzed the status of soil fertility and fertilizer application in yam production through field investigation and tracking monitoring, examined soil nutrient balance using the input-output model of nutrients in agricultural system, and assessed the environmental risks in the yam planting system. The results showed that: 1) the contents of soil organic matter and total N were extremely low, and the contents of available P and available Zn were both low; both nitrate and available Cu contents were at the middle level, the contents of soil slowly available K, available S, and exchangeable Ca and Mg were all extremely high, the contents of available K, available Fe, and available Mn were all at high level; 2) The nitrogen (N), phosphorus (P 2 O 5 ), and potassium (K 2 O) inputs were 575-943 kg·hm -2 , 341-981 kg·hm -2 , and 655-1219 kg·hm -2 during the whole growth period of yam, with chemical fertilizer accounting for 83.0%, 88.6%, and 91.3%, respectively; The input imbalance between organic and inorganic fertilizer, as well as the excessive nutrients input were prominent; 3) The surplus rate of soil nitrogen, phosphorus and potassium reached 271.14 kg·hm -2 , 466.34 kg·hm -2 , and 739.97 kg·hm -2 , with corresponding surplus ratio of 48.7%, 258.1%, and 324.5%, respectively, which all exceeded the environmental safety threshold and were classified as moderate risk, severe risk, and severe risk, respectively. The overall environmental risk caused by chemical fertilizer application in yam production had reached severe risk level.

Key Message: Endogenous and exogenous GA 3 responses to DoEXP and DoXTH depend on the DoGA20ox1, DoGA3ox1, DoGA2ox3, DoGA2ox4, DoGID1a, and DoDELLA1 to regulate yam tuber growth. Yam tuber undergoes significant alteration in morphogenesis and functions during growth, and gibberellins (GA) are considered potentially important regulators of tuber growth. However, it is little known about the regulation of GA metabolism and GA signaling components genes in tuber growth of yam. In this study, the cloning and expressions of GA 3 level, GA metabolism and signaling genes, and cell wall genes in tuber growth in response to GA 3 and GA biosynthesis inhibitor paclobutrazol (PP 333 ) treatments were studied. The contents of GA 3 accumulated at the tuber growth, with the highest levels in the early expansion stage. DoGA20ox1, DoGA3ox1, and four DoGA2ox genes were significantly abundant in the early expansion stage of tuber and gradually declined along with tuber growth. Three DoGID1 and three DoDELLA genes were showed different expression patterns in the early expansion stage of tuber and gradually declined along with tuber growth. Five DoEXP and three DoXTH genes expression levels were higher in the early expansion stage than in other stages. Exogenous GA 3 increased endogenous GA 3 levels, whereas the expression levels of DoGA20ox1, DoGA3ox1, DoGID1a, and DoDELLA1 were down-regulated in the early expansion stage of tuber by GA 3 treatment, DoGA2ox3 and DoGA2ox4 were up-regulated. PP 333 application exhibited opposite consequences. Thus, a mechanism of GA 3 regulating yam tuber growth by DELLA-dependent pathway is established., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

Our previous study has demonstrated that sulfated yam polysaccharide (SCYP) had a stronger immunomodulatory activity than yam polysaccharide (CYP). In order to investigate how the sulfated modification influence the immunological activity of CYP, this research was mainly focused on the study of gut microbiotal. The results showed that SCYP treatment could increase the digestive enzyme activities of colon contents and restore the production of short-chain fatty acids (SCFAs) in mice that were decreased by cyclophosphamide (Cy) treatment. Furthermore, SCYP treatment could modulate the structure of the gut microbiota, which was mainly manifest in the result of an increased abundances of Lactobacillus, Bacteroidetes and Akkermansia, and the decrease of the proportion of Proteobacteria and Verrucomicrobia in the microbial community. Diversity and overall structure of microbial community were also improved by SCYP treatment based on alpha-diversity and beta-diversity analysis results. The biomarkers of the gut microbial that were regulated by SCYP have been identified by linear discriminant analysis (LDA) effect size (LEfSe). These findings further indicate that there is great potential for SCYP to be developed into prebiotics or functional foods., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Leaves of the wild yam species Dioscorea sansibarensis display prominent forerunner or "drip" tips filled with extracellular bacteria of the species Orrella dioscoreae. 1 This species of yam is native to Madagascar and tropical Africa and reproduces mainly asexually through aerial bulbils and underground tubers, which also contain a small population of O. dioscoreae. 2 , 3 Despite apparent vertical transmission, the genome of O. dioscoreae does not show any of the hallmarks of genome erosion often found in hereditary symbionts (e.g., small genome size and accumulation of pseudogenes). 4-6 We investigated here the range and distribution of leaf symbiosis between D. sansibarensis and O. dioscoreae using preserved leaf samples from herbarium collections that were originally collected from various locations in Africa. We recovered DNA from the extracellular symbiont in all samples, showing that the symbiosis is widespread throughout continental Africa and Madagascar. Despite the degraded nature of this DNA, we constructed 17 symbiont genomes using de novo methods without relying on a reference. Phylogenetic and genomic analyses revealed that horizontal transmission of symbionts and horizontal gene transfer have shaped the evolution of the symbiont. These mechanisms could help explain lack of signs of reductive genome evolution despite an obligate host-associated lifestyle. Furthermore, phylogenetic analysis of D. sansibarensis based on plastid genomes revealed a strong geographical clustering of samples and provided evidence that the symbiosis originated at least 13 mya, earlier than previously estimated. 3 ., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Research on the processing of yam ( Dioscorea spp.) into flour is aimed at optimizing techniques to obtain a material with high physicochemical and functional properties. The present study investigates the effect of the processing techniques on the levels of inulin, organic acids, total phenolics (TP), antioxidant capacity, and polyphenol oxidase (PPO) and peroxidase (POD) activities, as well as on the physicochemical properties of flour derived from two yam species- Dioscorea esculenta and Dioscorea bulbifera . All tubers were peeled and sliced, then subjected to different processing techniques through blanching, soaking, and drying. The results revealed that freeze-drying appears to be the best technique in achieving the highest whiteness index of yam flour. This coincided well with the low phenolics content and POD activity, which suggests a reduced enzymatic browning reaction in the freeze-dried yam flour. On the other hand, chemical analyses showed that D. esculenta and D. bulbifera flours have the highest levels of inulin (23.0 and 27.8 g/100 g DW, respectively) and succinic acid (7.96 and 7.65 g/100 g DW, respectively) in the samples subjected to direct oven-drying. Oven drying without pretreatment neither blanching nor water steeping maintained antioxidant activity in the flour derived from both D. esculenta and D. bulbifera .

Background: Although tubers play a significant role in Brazilian agriculture, very little is known about the intake of tubers among the Brazilian population. The objective of this study was to characterize the intake of tubers across Brazil. The types of tubers consumed were quantified, and the impact of geographic and sociodemographic factors was assessed., Methods: This cross-sectional study is based on dietary intake data of 33,504 subjects obtained from the Brazilian National Dietary Survey. All tuber containing foods were identified, and the contribution of different tubers to overall tuber consumption in Brazil was quantified. Descriptive analyses assessed the impact of macroregion and sociodemographic characteristics on tuber consumption, and differences in intake were assessed using statistical tests. Lastly, the dietary intakes of tuber consumers and non-consumers were compared after adjusting for energy and covariates to determine if there were any major differences in dietary intakes between the two groups., Results: Fifty-five percent of the Brazilian population consumed tubers, which differed by macroregion. The intake of tubers among consumers also differed between macroregions. Overall, rural areas reported significantly higher mean daily intakes of tubers (122 g/day) among tuber consumers than urban areas (95 g/day). Mandioca and potato were the most commonly consumed tubers (59 and 43% prevalence, respectively, on any of the 2 days), while the highest daily intakes amongst tuber consumers across Brazil were noted for sweet potato (156 g/day) and potato (95 g/day). On a macroregion level, among tuber consumers, mandioca had the highest prevalence of consumption in the North (94%), Northeast (83%), and Central-West (68%), while consumption of potatoes was most prevalent in the Southeast (63%) and South (62%). Compared to women, small but significantly higher tuber intakes were noted for males (108 vs. 85 g/day). There were no significant differences in intakes among income quintiles. After adjusting for energy and other covariates, nutrient intakes between tuber and non-tuber consumers were not meaningfully different, with the exception of sodium (+ 6.0% comparing non-tuber to tuber consumers), iron (+ 6.1%), zinc (+ 5.7%), vitamin C (+ 8.3%), riboflavin (+ 9.0%), and folate (+ 7.9%)., Conclusions: Tuber consumption is influenced by regional and sociodemographic characteristics of the Brazilian population. When looking at energy-adjusted nutrient intakes, diets of tuber consumers have resulted in somewhat lower intakes of some micronutrients, namely riboflavin, folate, vitamin C, iron, sodium, and zinc.

The far Southwest Ethiopians transplant wild plant species to their gardens. One of such plant is the Dioscorea that we studied to assess the knowledge of wild yam and process of domestication. The study links two types of evidence to obtain insight about the process of yam domestication. We analyze two data sets derived from (1) ethnobotanical survey using 231 semi-structured interviews; and (2) morphological study in 47 yam accessions. Our study revealed that domestication is still active in some villages. Knowledge of yam domestication was shared by 44% of the farmers' even by those that have never practiced its domestication. Farmers who can describe the trend of domestication and the morphotypes of domesticate represented 21 and 28%, respectively. Farmers who have recent transplants in their garden varied from 4% in Bench to 10% in Sheko. The domestication process described by the two ethnic groups is similar. The duration of domestication can take up to six years, but with most of the individuals, it only takes three to five years. By linking the two types of evidence, two evolutionary processes are distinguished: (1) populations of recent domesticate expressing a domestication syndrome possibly belongs to the wild D. abyssinica or D. praehensilis , and (2) plants of incipient domesticate that might be derived from volunteers or diverse types of hybrids. Each of these processes can lead to integration of wild genotypes into the cultivated gene pool, and hence, enhance genetic diversity of cultivated yams. The domestication practices of traditional farmers should thus be taken into account if yam conservation and improvement plans need to be established.

Storage ability of trifoliate yam ( Dioscorea dumetorum ) is restricted by a severe post-harvest hardening (PHH) phenomenon, which starts within the first 24 h after harvest and renders tubers inedible. Previous work has only focused on the biochemical changes affecting PHH in D. dumetorum . To the best of our knowledge, the candidate genes responsible for the hardening of D. dumetorum have not been identified. Here, transcriptome analyses of D. dumetorum tubers were performed in yam tubers of four developmental stages: 4 months after emergence (4MAE), immediately after harvest (AH), 3 days after harvest (3DAH) and 14 days after harvest (14DAH) of four accessions (Bangou 1, Bayangam 2, Fonkouankem 1, and Ibo sweet 3) using RNA-Seq. In total, between AH and 3DAH, 165, 199, 128 and 61 differentially expressed genes (DEGs) were detected in Bayangam 2, Fonkouankem 1, Bangou 1 and Ibo sweet 3, respectively. Functional analysis of DEGs revealed that genes encoding for CELLULOSE SYNTHASE A ( CESA ), XYLAN O-ACETYLTRANSFERASE ( XOAT ), CHLOROPHYLL A/B BINDING PROTEIN 1 , 2 , 3 , 4 ( LHCB1 , LHCB2 , LHCB3 , and LCH4 transcription factor were predominantly and significantly up-regulated 3DAH, implying that these genes were potentially involved in the PHH as confirmed by qRT-PCR. A hypothetical mechanism of this phenomenon and its regulation has been proposed. These findings provide the first comprehensive insights into gene expression in yam tubers after harvest and valuable information for molecular breeding against the PHH.MYB transcription factor were predominantly and significantly up-regulated 3DAH, implying that these genes were potentially involved in the PHH as confirmed by qRT-PCR. A hypothetical mechanism of this phenomenon and its regulation has been proposed. These findings provide the first comprehensive insights into gene expression in yam tubers after harvest and valuable information for molecular breeding against the PHH.

Background: Greater yam (Dioscorea alata L.) is a major tropical and subtropical staple crop cultivated for its starchy tubers. Breeding of this dioecious species is hampered by its erratic flowering, yet little is currently known on the genetic determinism of its sexual reproduction., Result: Here we used a genome-wide association approach and identified a major genetic barrier to reproduction in yam on chromosome 1, as represented by two candidate genes. A deleterious effect on male fitness could be hypothesized considering the involvement of these two genes in male reproduction and the low frequency of this non-flowering dominant allele within the male genepool. We also extended the hypothesis of a XX/XY sex-determination system located on chromosome 6 in D. alata to encompass most of the species diversity. Moreover, a kompetitive allele-specific PCR (KASPar) marker was designed and validated that enables accurate cultivar sex estimation. The reconstruction of chromosome 6 associated with the detection of highly putative structural variations confirmed the possible involvement of a major part of the chromosome., Conclusion: The findings of this study, combined with proper estimation of accession ploidy levels to avoid endosperm incompatibility issues, could facilitate the design of future promising parental combinations in D. alata breeding programs. Moreover, the discovery of this genetic barrier to reproduction opens new avenues for gaining insight into yam reproductive biology and diversification.

For many of the developing world's poorest farmers and food-insecure people, roots, tubers, bananas and plantain crops (RTBs) serve as a critical source of food, nutrition and cash income. RTBs have been particularly important in areas where local agri-food systems are under stress. Under such circumstances, growers, processors and traders often see opportunities to improve food security or increase their incomes with those crops due to shifting tastes and preferences for food and non-food products. Since the early 1990s, cassava output surged in sub-Saharan Africa, while potato production expanded rapidly in Asia. RTBs are consumed by over three billion people in developing countries with a market value of US$ 339 billion. This paper analyses the major changes in production, utilisation and trade of RTBs over the last six decades, assesses estimates of their future trajectory and offers recommendations so that they might achieve their full potential., (© 2020 The Authors. International Journal of Food Science & Technology published by John Wiley & Sons Ltd on behalf of Institute of Food, Science and Technology (IFSTTF).)