Background Seed weight is a complex yield-related trait with a lot of quantitative trait loci (QTL) reported through linkage mapping studies. Integration of QTL from linkage mapping into breeding program is challenging due to numerous limitations, therefore, Genome-wide association study (GWAS) provides more precise location of QTL due to higher resolution and diverse genetic diversity in un-related individuals. Results The present study utilized 573 breeding lines population with 61,166 single nucleotide polymorphisms (SNPs) to identify quantitative trait nucleotides (QTNs) and candidate genes for seed weight in Chinese summer-sowing soybean. GWAS was conducted with two single-locus models (SLMs) and six multi-locus models (MLMs). Thirty-nine SNPs were detected by the two SLMs while 209 SNPs were detected by the six MLMs. In all, two hundred and thirty-one QTNs were found to be associated with seed weight in YHSBLP with various effects. Out of these, seventy SNPs were concurrently detected by both SLMs and MLMs on 8 chromosomes. Ninety-four QTNs co-localized with previously reported QTL/QTN by linkage/association mapping studies. A total of 36 candidate genes were predicted. Out of these candidate genes, four hub genes ( Glyma06g44510, Glyma08g06420, Glyma12g33280 and Glyma19g28070 ) were identified by the integration of co-expression network. Among them, three were relatively expressed higher in the high HSW genotypes at R5 stage compared with low HSW genotypes except Glyma12g33280 . Our results show that using more models especially MLMs are effective to find important QTNs, and the identified HSW QTNs/genes could be utilized in molecular breeding work for soybean seed weight and yield. Conclusion Application of two single-locus plus six multi-locus models of GWAS identified 231 QTNs. Four hub genes ( Glyma06g44510 , Glyma08g06420 , Glyma12g33280 & Glyma19g28070 ) detected via integration of co-expression network among the predicted candidate genes.

Seed-weight is one of the most important traits determining soybean yield. Hence, it is prerequisite to have detailed understanding of the genetic basis regulating seed-weight for the development of improved cultivars. In this regard, the present study used high-density interspecific linkage map of NJIR4P recombinant inbred population evaluated in four different environments to detect stable Quantitative trait loci (QTLs) as well as mine candidate genes for 100-seed weight. In total, 19 QTLs distributed on 12 chromosomes were identified in all individual environments plus combined environment, out of which seven were novel and eight are stable identified in more than one environment. However, all the novel QTLs were minor (R2 < 10%). The remaining 12 QTLs detected in this study were co-localized with the earlier reported QTLs with narrow genomic regions, and out of these only 2 QTLs were major (R2 > 10%) viz., qSW-17-1 and qSW-17-4. Beneficial alleles of all identified QTLs were derived from cultivated soybean parent (Nannong493-1). Based on Protein ANalysis THrough Evolutionary Relationships, gene annotation information, and literature search, 29 genes within 5 stable QTLs were predicted to be possible candidate genes that might regulate seed-weight/size in soybean. However, it needs further validation to confirm their role in seed development. In conclusion, the present study provides better understanding of trait genetics and candidate gene information through the use high-density inter-specific bin map, and also revealed considerable scope for genetic improvement of 100-seed weight in soybean using marker-assisted breeding.

A B S T R A C TPhosphorus is a major limiting nutrient in soils in Ghana. Selection of cowpea varieties that produce good seed yield under low soil phosphorus or those with high phosphorus response efficiency can be a low input approach in solving this problem in Ghana. Two seasons experiments were conducted to evaluate influence of phosphorus (P) fertilizer on growth, nodulation and yield in cowpea. The experiment comprised 12 treatment combinations of 3 cowpea varieties and 4 levels of triple super phosphate (46% P 2 O 5 ) laid out as a factorial in RCBD with four replications. The cowpea varieties were Asetenapa (IT81D-1951), Asomdwee (IT94K-410-2) and IT89KD-347-57 and levels of P were 0, 20, 40 and 60 kg haG 1 P 2 O 5 . In the present study, Asomdwee and IT89KD-347-57 recorded the highest and lowest crop growth of 7.88 and 2.02 g mG 2 dayG 1 at 45 and 60 days after planting, respectively. Growth rate was not consistent with P application; however, application rate of 60 kg haG 1 P 2 O 5 yielded the least growth rate in the entire study period except for 60 days after planting in the minor season. Statistically, Asetenapa and Asomdwee recorded similar number, effectiveness and dry weight of nodules and were significantly different from that of IT89KD-347-57 in both seasons. Number, effectiveness and dry weight of nodules in all varieties were directly proportional to rates of P fertilizer application in both seasons. Asomdwee produced the highest seed yield of 1557.00 and 1415.00 kg haG 1 for major and minor seasons, respectively. The rate of P fertilizer application was directly proportional to the seed yield in all three cowpea varieties. The highest seed yield of 1682.00 and 1476.00 kg haG 1 for major and minor seasons, respectively was produced at 60 kg haG 1 P 2 O 5 application. Farmers are, therefore, encouraged to use P fertilizer in cowpea production in Ghana.

Plant height (PH) is an important agronomic trait that is closely related to soybean yield and quality. However, it is a complex quantitative trait governed by multiple genes and is influenced by environment. Unraveling the genetic mechanism involved in PH, and developing soybean cultivars with desirable PH is an imperative goal for soybean breeding. In this regard, the present study used high-density linkage maps of two related recombinant inbred line (RIL) populations viz., MT and ZM evaluated in three different environments to detect additive and epistatic effect quantitative trait loci (QTLs) as well as their interaction with environments for PH in Chinese summer planting soybean. A total of eight and 12 QTLs were detected by combining the composite interval mapping (CIM) and mixed-model based composite interval mapping (MCIM) methods in MT and ZM populations, respectively. Among these QTLs, nine QTLs viz., QPH-2, qPH-6-2MT, QPH-6, qPH-9-1ZM, qPH-10-1ZM, qPH-13-1ZM, qPH-16-1MT, QPH-17 and QPH-19 were consistently identified in multiple environments or populations, hence were regarded as stable QTLs. Furthermore, Out of these QTLs, three QTLs viz., qPH-4-2ZM, qPH-15-1MT and QPH-17 were novel. In particular, QPH-17 could detect in both populations, which was also considered as a stable and major QTL in Chinese summer planting soybean. Moreover, eleven QTLs revealed significant additive effects in both populations, and out of them only six showed additive by environment interaction effects, and the environment-independent QTLs showed higher additive effects. Finally, six digenic epistatic QTLs pairs were identified and only four additive effect QTLs viz., qPH-6-2MT, qPH-19-1MT/QPH-19, qPH-5-1ZM and qPH-17-1ZM showed epistatic effects. These results indicate that environment and epistatic interaction effects have significant influence in determining genetic basis of PH in soybean. These results would not only increase our understanding of the genetic control of plant height in summer planting soybean but also provide support for implementing marker assisted selection (MAS) in developing cultivars with ideal plant height as well as gene cloning to elucidate the mechanisms of plant height.

Introduction The willingness of Africa’s population to patronise the COVID-19 vaccines is critical to the efficiency of national immunisation programmes. This study surveys the views of adult African inhabitants toward vaccination and the possibility of participating or not participating in governments’ efforts to get citizens vaccinated. Method A cross-sectional online survey of adult Africans was undertaken from December 2020 to March 2021. Responses were anonymised. The Pearson Chi-square test was performed to determine whether or not there were any variations in knowledge, awareness, perception and acceptance of the COVID-19 vaccines among the participants. Binomial logistic regression was used to evaluate the factors associated with willingness to accept the COVID-19 vaccines and participate in immunisation programmes. Results The results indicate that COVID-19 vaccines are more likely to be used by adult Africans over the age of 18 who are largely technologically savvy (55 percent) if the vaccine is made broadly available. A total of 33 percent of those who responded said they were unlikely to receive the vaccine, with another 15 percent stating they were undecided. Aside from that, we found that vaccine hesitancy was closely associated with socio-demographic characteristics such as age, gender, education and source of information. We also found that there were widespread conspiracies and myths about the COVID-19 vaccines. Conclusion More than one-third of African adults who participated in the survey indicated they would not receive the COVID-19 vaccine, with majority of them expressing skepticisms about the vaccine’s efficacy. It is possible that many of the people who would not be vaccinated would have an impact on the implementation of a COVID-19 immunisation programme that is meant for all of society. Majority of the respondents were unwilling to pay for the COVID-19 vaccines when made available. An awareness campaign should be focused on promoting the benefits of vaccination at the individual and population levels, as well as on taking preemptive actions to debunk misconceptions about the vaccines before they become further widespread.