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BackgroundYam production in sub-Saharan African countries faces challenges due to susceptibility to yam mosaic virus (YMV) disease, leading to significant yield losses. Dioscorea praehensilis, a semi-cultivated yam species known for its high yield and resistance to YMV, can be utilized as a new variety and a gene source to enhance tuber yield and YMV resistance of White Guinea yam. Investigating the genetic basis of tuber yield-related traits and YMV resistance in D. praehensilis through association mapping will facilitate the traits discovery and deployment into the yam breeding program.MethodologyA total of 132 D. praehensilis genotypes were evaluated in 2022 and 2023 seasons for tuber yield per plant, tuber size ratio and for mosaic virus severity response. The genotypes were sequenced using SNP markers generated from Diversity Array Technology Platform. The trait association analysis was conducted using mixed linear model implemented in GWASpoly package followed for putative genes analysis.ResultsPopulation structure and phylogeny analyses using 4,525 single nucleotide polymorphism (SNP) markers grouped the 132 D. praehensilis genotypes into three clusters. Using multiple gene action models which include dominant, additive, and general models, 27 SNP markers were significantly identified to be associated with the tuber yield, tuber size ratio and yam mosaic virus severity. Of these 27 SNPs, we identified three and two SNP markers for tuber yield and yam mosaic virus severity, respectively as stable markers across years. Using gene annotation, we identified 10 putative genes such as Serine/threonine-/dual specificity protein kinase, catalytic domain involved in starch biosynthesis and Ribosomal protein L5 involved in defense signaling against virus diseases. The marker effect revealed that alleles CC and TT were associated with high tuber yield, while AA and AC were linked with low tuber yield. For YMV severity response, alleles CC and CT were linked with low YMV severity, while TT was associated high YMV severity prediction.ConclusionThe results of this study offer valuable insights into comprehending the functional networks involved in developing strategies to enhance tuber yield and resistance to yam mosaic virus in Dioscorea spp. The markers and candidate genes discovered in this research will serve as crucial genomic resources for selection of D. praehensilis and other yam species.

IntroductionBush yam (Dioscorea praehensilis Benth.) is an important semi-domesticated food crop in West Africa. Limited information on the genetic architecture and its poor post-harvest tuber quality traits significantly hinder its use as food and source of income. Hence, dissecting the genetics underlying the expression of its post-harvest tuber quality traits is essential for establishing proper breeding schemes.MethodsIn this study, 138 D. praehensilis accessions collected in Ghana were sequenced using Diversity Array Technology (DArTSeq). The materials were profiled for dry matter content (DMC), tuber flesh oxidation (TBOXI) and for tuber flesh hardness (TBhard) during two cropping seasons.Results and discussionDiversity assessment using population structure, principal component analysis and hierarchical clustering methods revealed the presence of three major groups. Six genetic models were used for the trait association analysis using multiple random locus mixed linear model (MrMLM). Sixteen SNP markers distributed across the yam genome were identified to be associated with the evaluated traits. The associated SNP markers displayed a phenotypic variance ranged from 4.22% in TBHard to 16.92% in TBOXI. A total 25 putative candidate genes were identified around the SNP markers. The putative genes were identified to play key roles in tuber bulking, oxidative browning and starch hydroxylase. This study provides a valuable insight on the genetics underlying tuber quality traits in bush yam and opens avenues for developing genomic resources to improve D. praehensilis.

Highly specialized cryptochirid crabs are obligate symbionts of scleractinian corals in tropical and subtropical seas. General morphologies of cryptochirid crabs remain poorly described due to their small size and difficulties in collection; thus, the current inventory is probably an underestimation. In the present study, we sampled cryptochirid crabs from coral communities in Hong Kong. In the literature, only Cryptochirus hongkongensis (now Neotroglocarcinus hongkongensis) with unknown hosts had been recorded in Hong Kong since 1936. In addition to morphological examination, identification in the present study is further supported by sequence divergence of mitochondrial cytochrome c oxidase I (COI) and 16S ribosomal DNA markers. Six operative taxonomic units (OTUs), representing four species and one species complex with two species, were revealed among our material: Cryptochirus coralliodytes, Lithoscaptus paradoxus, Lithoscaptus doughnut sp. nov., Lithoscaptus scottae sp. nov., and Xynomaia sheni species complex. Morphological description of these species is provided, including description of the two new pseudocryptic species. The hosts of the genus Lithoscaptus belong largely to the Merulinidae, while L. doughnut sp. nov. inhabits the Plesiastreidae.

Dioscorea praehensilis Benth. is a semi-wild yam species and a valuable source of resistance trait genes. To access the agronomic and tuber quality performance, eleven quantitative phenotypic traits were used to discriminate and identify promising accessions among 162 accessions of D. praehensilis collected in Ghana. Significant and high genetic variability (p < 0.001) for all eleven quantitative traits was found among the evaluated accessions. Moderate broad-sense heritability (H2) (30–60%) was observed for all the evaluated quantitative traits except the response to YMV and tuber hardness. The accessions were clustered into three groups; each cluster displayed genotypes with good potentiality for the different traits evaluated. Path coefficient analysis revealed positive contributions (p < 0.01) of the number of tubers per plant, tuber length, tuber width, stem internode length, number of internodes, and tuber flesh hardness to the total tuber weight per plant. Through the multi-trait genotype–ideotype distance index (MGIDI), 24 accessions were identified from the 162 evaluated accessions as top-ranking and could be used as progenitors for trait introgression. The results of this study provide insight for future yam breeding and improvement programs in West Africa.

Anna Hilyard,1,2 Julia Kingsley,1 David Sommerfield,1,3,4 Susan Taylor,1,5 Natasha Bear,6 Noula Gibson7,8 1Complex Pain Service, Perth Children’s Hospital, Perth, Western Australia, Australia; 2Discipline of Psychology, College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia, Australia; 3Department of Anaesthesia and Pain Management, Perth Children’s Hospital, Perth, Australia; 4Medical School, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Australia; 5School of Occupational Therapy, Social Work and Speech Pathology, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia; 6Department of Child Research, Child Adolescent Health Service, Perth, Western Australia, Australia; 7Physiotherapy Department, Perth Children’s Hospital, Perth, Western Australia, Australia; 8School of Physiotherapy and Exercise Science, Faculty of Health Sciences, Curtin University, Perth, Western Australia, AustraliaCorrespondence: Anna HilyardComplex Pain Service, Perth Children’s Hospital, Locked Bag 2010, Nedlands, Western Australia 6909, AustraliaTel +6186456 4341Email anna.hilyard@health.wa.gov.auPurpose: Chronic pain is common in adolescents. Evidence-based guidelines recommend interdisciplinary treatment, but access is limited by geography. The development of hybrid programs utilizing both face-to-face and videoconference treatment may help overcome this. We developed a 7-week hybrid pediatric interdisciplinary pain program (Hybrid-PIPP) and wished to compare it to individual face-to-face sessions (Standard Care). Our objective was to test the feasibility of a protocol that used a matched pair un-blinded randomized controlled design to investigate the efficacy and cost-effectiveness of the Hybrid-PIPP compared to Standard Care.Patients and Methods: Parent–adolescent dyads were recruited from tertiary pediatric clinics and matched by disability before randomization to minimize allocation bias. The adolescents (aged 11– 17) had experienced primary pain for > 3 months. Hybrid-PIPP involved 11 hrs of group therapy and 4 individual videoconference sessions. Standard care was provided by the same clinical team, using the same treatment model and similar intensity as the Hybrid-PIPP. The intention was to recruit participants for 3 Hybrid-PIPP groups with a comparison stream. Recruitment was ceased after 2 groups due to the high participant disability requiring more intensive intervention.Results: Eighteen dyads were screened and 13 randomized (7 Hybrid-PIPP, 6 Standard Care, 2 unsuitable, 3 unallocated when the study was stopped). The study met a priori feasibility criteria for staff availability; recruitment rate; treatment completion; and data collection. Global satisfaction ratings were similar in both streams (SC median 7, range 5– 9 and Hybrid-PIPP median 8.5, range 5– 10). Challenges were identified in both streams. A future modified Hybrid-PIPP was considered acceptable if the intensity is increased to manage the high level of disability. Standard care was considered inefficient. No adverse events were reported.Conclusion: The study determined that the protocol met a priori feasibility criteria, but to be practicable in a real world, health environment requires significant modifications.Registration: ANZTR(ACTRN2614000489695).Keywords: videoconferencing, telemedicine, interdisciplinary pain management, hybrid treatment, allied health, pediatric pain management

[This corrects the article DOI: 10.1371/journal.pone.0216107.].

Habitat complexity plays a critical role in shaping biotic assemblages and ecosystem processes. While the impacts of large differences in habitat complexity are often well understood, we know less about how subtle differences in structure affect key ecosystem functions or properties such as biodiversity and biomass. The late-successional seagrass Posidonia australis creates vital habitat for diverse fauna in temperate Australia. Long-term human impacts have led to the decline of P. australis in some estuaries of eastern Australia, where it is now classified as an endangered ecological community. We examined the influence of P. australis structural complexity at small (seagrass density) and large (meadow fragmentation) spatial scales on fish and epifauna communities, predation and sediment erosion. Fine-scale spatially balanced sampling was evenly distributed across a suite of environmental covariates within six estuaries in eastern Australia using the Generalised Random Tessellation Structures approach. We found reduced erosion in areas with higher P. australis density, greater abundance of fish in more fragmented areas and higher fish richness in vegetated areas further from patch edges. The abundance of epifauna and fish, and fish species richness were higher in areas with lower seagrass density (seagrass density did not correlate with distance to patch edge). These findings can inform seagrass restoration efforts by identifying meadow characteristics that influence ecological functions and processes.

Bush yam (Dioscorea praehensilis Benth.) is an important food and cash crop species in some West and Central African countries. Unfortunately, several socioeconomic, cultural, nutritional, and agronomic constraints hinder its cultivation, and thus lead to its underutilization and gradual disappearance. To effectively promote its cultivation and utilization, knowledge of its diversity, distribution, management, and farmers’ varietal preferences is necessary. This study, therefore, used a participatory rural appraisal survey to assess such information in 23 villages from three regions of Ghana. A total of 42 D. praehensilis morphotypes were recorded and grouped in seven classes based on the tuber flesh colour. The Shannon diversity index (H’ = 1.88), equitability (0.65), and Margalef species richness (2.53) revealed the presence of moderate diversity and distribution in the surveyed regions. Farmers’ variety trait preferences included mainly the early maturity (21.1%), smooth tuber texture (16.5%), stability in tuber flesh colour (7.86%), good storage aptitude (7.6%), and high tuber productivity (12.8%). In contrast, D. praehensilis production and utilization rates have declined mainly due to poor culinary quality (39.9%) and poor agronomic traits (20.7%) of most morphotypes. Survey results showed that D. praehensilis is largely an in-situ conserved species in Ghana (60.0%). This study provided an insight on D. praehensilis diversity, distribution and farmers’ varietal preferences in Ghana which will guide its genetic resource conservation and plant breeding interventions.

Intertidal mudflat crabs of the genus Metaplax H. Milne Edwards, 1852 (Crustacea: Brachyura: Varunidae) from China, Taiwan, and northern Vietnam are taxonomically revised by morphological and molecular evidence. These crabs show sexual dimorphism and morphological variation of a considerable range in the infraorbital ridge, one of the primary features previously used for species identification. In this study, four species were identified from the region: M. elegans De Man, 1888; M. longipes Stimpson, 1858; M. sheni Gordon, 1930; and M. tredecim Tweedie, 1950. Based on the results of the morphological examination, and as confirmed by molecular evidence from mitochondrial cytochrome oxidase subunit I (COI), taxonomic confusion surrounding M. longipes was resolved, and M. takahasii Sakai, 1939, is considered a junior synonym of M. longipes. The geographical distribution of Metaplax longipes extends along the shores of China, north to Jiangsu, whereas the Southeast Asian M. tredecim was newly recorded from northern Vietnam and Hong Kong.

Cassava is the 6th most important source of dietary energy in the world but its root system architecture (RSA) had seldom been quantified. Ability to select superior genotypes at juvenile stages can significantly reduce the cost and time for breeding to bridge the large yield gap. This study adopted a simple approach to phenotyping RSA traits of juvenile and mature cassava plants to identify genotypic differences and the relationships between juvenile traits and harvest index of mature plants. Root classes were categorised and root and shoot traits of eight (8) juvenile pot-grown cassava genotypes, were measured at 30 and 45 days after planting (DAP). The same or related traits were measured at 7 months after planting of the same genotypes grown in the field while yield and yield components were measured in 12-months old field-grown plants. The field experiment was done in 2017 and repeated in 2018. Differences between genotypes for the measured traits were explored using analysis of variance (ANOVA) while traits in juvenile plants were correlated or regressed onto traits measured in 7- and 12-months old plants. The results show significant genotypic variations for most of the traits measured in both juvenile and 7-months old plants. In the 12-months old plants, differences between genotypes were consistent for both 2017 and 2018. Broad-sense heritability was highest for the number of commercial roots (0.87) and shoot fresh weight (0.78) and intermediate for the total number of roots (0.60), harvest index (0.58), fresh weight of roots (0.45). For all the sampling time points or growth stages, there were greater correlations between traits measured at a particular growth stage than between the same traits at different growth stages. However, some juvenile-mature plant trait relationships were significant, positive and consistent for both 2017 and 2018. For example, total root length and the total number of roots in 30 DAP, and branching density of upper nodal roots in 45 DAP, positively correlated with harvest index of 12-months old plants in both 2017 and 2018. Similarly, the diameter of nodal roots, for example, had a negative, significant correlation with fresh shoot biomass of mature plants in both 2017 and 2018. Regression of traits measured in 30 DAP explained up to 22% and 36% of the variation in HI of mature plants in 2017 and 2018, respectively. It is concluded that the simple, rapid, inexpensive phenotyping approach adopted in this study is robust for identifying genotypic variations in juvenile cassava using root system traits. Also, the results provide seminal evidence for the existence of useful relationships between traits of juvenile and mature cassava plants that can be explored to predict yield and yield components.

Yam (Dioscorea spp.) is an important food security crop in the tropics and subtropics. However, it is characterized by a narrow genetic base within cultivated and breeding lines for tuber yield, disease resistance, and postharvest traits, which hinders the yam breeding progress. Identification of new sources of desirable genes for these traits from primary and secondary gene pools is essential for this crop improvement. This study aimed at identifying potential sources of genes for yield and quality traits in a panel of 162 accessions of D. praehensilis, a semi-domesticated yam species, for improving the major yam species, D. rotundata. Significant differences were observed for assessed traits (p < 0.05), with D. praehensilis genotypes out-performing the best D. rotundata landraces for tuber yield (23.47 t ha−1), yam mosaic virus (YMV) resistance (AUDPC = 147.45), plant vigour (2.43) and tuber size (2.73). The study revealed significant genotypic (GCV) and phenotypic (PCV) coefficients of variance for tuber yield, YMV severity score, and tuber flesh oxidation. We had also a medium-to-high broad-sense heritability (H2b) for most of the traits except for the dry matter content and tuber flesh oxidation. This study identified some promising D. praehensilis genotypes for traits such as high yield potential (WNDpr76, CDpr28, CDPr7, EDpr14, and WNDpr63), resistance to YMV (WNDpr76, CDpr7, EDpr14, CDpr28, and EDpr13), high dry matter content (WNDpr76, CDpr28, and WNDpr24), low tuber flesh oxidation (WNDpr76, CDpr5, WNDpr31, CDpr40, and WNDpr94) and high number of tubers per plant (WNDpr76, CDpr7, CDpr68, CDpr29, and CDpr58). These genotypes could, therefore, be employed in breeding programmes to improve the white Guinea yam by broadening its genetic base.

[This corrects the article DOI: 10.1371/journal.pone.0190370.].

Seagrasses are in decline globally due to sustained pressure from coastal development, water quality declines and the ongoing threat from climate change. The result of this decline has been a change in coastal productivity, a reduction in critical fisheries habitat and increased erosion. Attempts to slow this decline have included legislative protection of habitat and direct restoration efforts. Monitoring the success of these approaches requires tracking changes in the abundance of seagrasses, but such monitoring is frequently conducted at either too coarse a spatial scale, or too infrequently to adequately detect changes within individual meadows. Here, we used high resolution aerial imagery to quantify the change in meadows dominated by Posidonia australis over five years at 14 sites in five estuaries in south-eastern Australia. Australia has some of the world's most diverse and extensive seagrass meadows, but the widely distributed P. australis has a slow growth rate, recovers poorly after disturbance, and suffers runaway attrition if the conditions for recovery are not met. In 2010, after declines of 12-57% between the 1940s and 1980s, P. australis was listed as a threatened ecological community in New South Wales. We quantified changes in area at fine spatial scales and, where loss was observed, describe the general patterns of temporal decline within each meadow. Our results demonstrate that seagrass meadows dominated by P. australis underwent declines of ~ 2-40% total area at 11 out of 14 study sites between 2009 and 2014. In the iconic Sydney Harbour, our analyses suggest that P. australis meadows are declining at an average rate greater than 10% yr-1, exceeding the global rate of seagrass decline. Highlighting these alarming declines across the study region should serve as means to prioritise management action and review the effectiveness of legislative listing as a method to limit impacts at an ecosystem level.

Abstract Background While chronic β-Hydroxy β-Methylbutyrate (HMB) supplementation (≥ 2 wk) lowers exercise induced muscle damage, its acute or timing effects have not been examined. The purpose of this study was to investigate the acute and timing effects of oral HMB supplementation on serum creatine kinase (CK), lactate dehydrogenase (LDH), muscle soreness, and maximal voluntary contraction (MVC). Methods Sixteen non-resistance trained men (22 ± 2 yrs) were assigned to HMB-Pre or HMB-Post groups. In a crossover design, all subjects performed 55 maximal eccentric knee extension/flexion contractions on 2 occasions on either the right or left leg. HMB-Pre (N = 8) randomly received 3 grams of either a placebo or HMB before and a placebo after exercise. HMB-Post (N = 8) received a placebo before and either 3 grams of HMB or a placebo after exercise. Muscle damage tests were recorded before, at 8, 24, 48, and 72 hrs post exercise. Results There was a reduction in MVC and an increase in soreness in the quadriceps and hamstrings following exercise (p < 0.001). Although HMB-Pre approached significance in attenuating soreness for the quadriceps (p = 0.07), there was no time × group effect. Serum indices of damage increased, peaking at 48 hrs for CK (773%) (p < 0.001) and 72 hrs for LDH (180%) (p < 0.001). While there were no time × group effects of HMB on CK and LDH, post hoc analysis revealed that only HMB-Pre showed no significant increase in LDH levels following exercise. Conclusion Our findings suggest no clear acute or timing effects of HMB supplementation. However, consuming HMB before exercise appeared to prevent increases in LDH.

Background: Yam production in sub-Saharan African countries faces challenges due to susceptibility to yam mosaic virus (YMV) disease, leading to significant yield losses. Dioscorea praehensilis, a semi-cultivated yam species known for its high yield and resistance to YMV, can be utilized as a new variety and a gene source to enhance tuber yield and YMV resistance of White Guinea yam. Investigating the genetic basis of tuber yield-related traits and YMV resistance in D. praehensilis through association mapping will facilitate the traits discovery and deployment into the yam breeding program. Methodology: A total of 132 D. praehensilis genotypes were evaluated in 2022 and 2023 seasons for tuber yield per plant, tuber size ratio and for mosaic virus severity response. The genotypes were sequenced using SNP markers generated from Diversity Array Technology Platform. The trait association analysis was conducted using mixed linear model implemented in GWASpoly package followed for putative genes analysis. Results: Population structure and phylogeny analyses using 4,525 single nucleotide polymorphism (SNP) markers grouped the 132 D. praehensilis genotypes into three clusters. Using multiple gene action models which include dominant, additive, and general models, 27 SNP markers were significantly identified to be associated with the tuber yield, tuber size ratio and yam mosaic virus severity. Of these 27 SNPs, we identified three and two SNP markers for tuber yield and yam mosaic virus severity, respectively as stable markers across years. Using gene annotation, we identified 10 putative genes such as Serine/threonine-/dual specificity protein kinase, catalytic domain involved in starch biosynthesis and Ribosomal protein L5 involved in defense signaling against virus diseases. The marker effect revealed that alleles CC and TT were associated with high tuber yield, while AA and AC were linked with low tuber yield. For YMV severity response, alleles CC and CT were linked with low YMV severity, while TT was associated high YMV severity prediction. Conclusion: The results of this study offer valuable insights into comprehending the functional networks involved in developing strategies to enhance tuber yield and resistance to yam mosaic virus in Dioscorea spp. The markers and candidate genes discovered in this research will serve as crucial genomic resources for selection of D. praehensilis and other yam species. [ABSTRACT FROM AUTHOR]

Introduction: Bush yam (Dioscorea praehensilis Benth.) is an important semidomesticated food crop in West Africa. Limited information on the genetic architecture and its poor post-harvest tuber quality traits significantly hinder its use as food and source of income. Hence, dissecting the genetics underlying the expression of its post-harvest tuber quality traits is essential for establishing proper breeding schemes. Methods: In this study, 138 D. praehensilis accessions collected in Ghana were sequenced using Diversity Array Technology (DArTSeq). The materials were profiled for dry matter content (DMC), tuber flesh oxidation (TBOXI) and for tuber flesh hardness (TBhard) during two cropping seasons. Results and discussion: Diversity assessment using population structure, principal component analysis and hierarchical clustering methods revealed the presence of three major groups. Six genetic models were used for the trait association analysis using multiple random locus mixed linear model (MrMLM). Sixteen SNP markers distributed across the yam genome were identified to be associated with the evaluated traits. The associated SNP markers displayed a phenotypic variance ranged from 4.22% in TBHard to 16.92% in TBOXI. A total 25 putative candidate geneswere identified around the SNP markers. The putative genes were identified to play key roles in tuber bulking, oxidative browning and starch hydroxylase. This study provides a valuable insight on the genetics underlying tuber quality traits in bush yam and opens avenues for developing genomic resources to improve D. praehensilis. [ABSTRACT FROM AUTHOR]