The Impact of Salinity on the Productivity and Quality of Durum and bread Wheat

Salinity poses a significant challenge to the quality and productivity of crops. In the primary wheat cultivation areas worldwide, salinity negatively affects wheat growth, yield, and quality. To address this issue, the development of tolerant wheat varieties through selective breeding techniques is essential. The aim of this study was to assess the effects of salinity on grain yield, protein content, and thousand-kernel weight (TKW) among 55 different varieties and accessions of bread and durum wheat. The findings revealed that the application of salt treatment (100 mM NaCl solution) resulted in reduced growth and yield production in 45 bread and durum wheat varieties. However, 6 durum wheat varieties, 3 durum wheat accessions, and 1 common wheat accession showed insignificant susceptibility to salinity. These included Chryssodur from Greece, Saragolla, Silur, and Dakter from Italy, Sculptur from France, Karim from Tunisia, Algeria 70-2 from Algeria, Ethiopia 201 and Ethiopia 229 from Ethiopia, and the Morocco 85 accession of bread wheat from Morocco. The decline in grain yield could be attributed to salinity, which led to a decrease in photosynthetic capacity, resulting in reduced starch synthesis and accumulation in the grain. Furthermore, the study demonstrated that winter wheat exhibited greater tolerance to salt stress compared to spring wheat, and durum wheat displayed higher tolerance than common wheat. Additionally, salt accumulation was found to increase protein content in five varieties and one accession of durum wheat. This variation may be linked to the relatively stable nitrogen metabolism under salt stress, contributing to higher protein concentrations. TKW also decreased in all 10 varieties and accessions, irrespective of the species

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Mapping novel QTLs for tolerance to salt stress at the late vegetative stage in durum wheat (Triticum durum L.)

Salt stress adversely affects the global durum wheat productivity. Breeding for salinity tolerance is an effective approach to improve crop production under saline conditions provided it is based on a good understanding of the genetic control of salinity tolerance. The present study was conducted, at the university of Tsukuba (in 2014), with the objective of mapping QTLs conferring salt tolerance in F2:3 populations of durum wheat derived from a cross between Razzek (salt sensitive variety) and Saragolla (salt tolerant variety). Two QTLs for salt tolerance were detected on chromosome 4B and 5B conferring the proportion of dead leaves with major effects. These two QTLs, which explained 68% of total phenotypic variation of %DL are an ideal candidate for Marker Assisted Selection (MAS) in wheat breeding programs and selection strategies to increase wheat production under saline conditions in order to meet the increasing global demand

Association of matrix metalloproteinase-2 gene polymorphisms with susceptibility to type 2 diabetes: A case control study

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