Molecular breeding for resilience in maize - A review

Abiotic and biotic constraints have widespread yield reducing effects on maize and should receive high priority for maize breeding research. Molecular Breeding offers opportunities for plant breeders to develop cultivars with resilience to such diseases with precision and in less time duration. The term molecular breeding is used to describe several modern breeding strategies, including marker-assisted selection, marker-assisted backcrossing, marker-assisted recurrent selection and genomic selection. Recent advances in maize breeding research have made it possible to identify and map precisely many genes associated with DNA markers which include genes governing resistance to biotic stresses and genes responsible for tolerance to abiotic stresses. Marker assisted selection (MAS) allows monitoring the presence, absence of these genes in breeding populations whereas marker assisted backcross breeding effectively integrates major genes or quantitative trait loci (QTL) with large effect into widely grown adapted varieties. For complex traits where multiple QTLs control the expression, marker assisted recurrent selection (MARS) and genomic selection (GS) are employed to increase precision and to reduce cost of phenotyping and time duration. The biparental mapping populations used in QTL studies in MAS do not readily translate to breeding applications and the statistical methods used to identify target loci and implement MAS have been inadequate for improving polygenic traits controlled by many loci of small effect. Application of GS to breeding populations using high marker densities is emerging as a solution to both of these deficiencies. Hence, molecular breeding approaches offers ample opportunities for developing stress resilient and high-yielding maize cultivars

Pathogenic variability in Exserohilum turcicum and identification of resistant sources to turcicum leaf blight of maize (Zea mays L.)

Turcicum leaf blight of maize incited by Exserohilum turcicum (Pass.) Leonard and Suggs is the major limiting factor of maize production in temperate agro-ecologies. Disease management through host plant resistance is the most effective strategy. In the present study among 26 maize genotypes which were initially screened for resistance against E. turcicum under field conditions, 8 genotypes viz., PS 39, CML 451, CML 470, CML 472, VL 1030, VL 1018140, VL1018527 and SMI178-1 were found resistant when screened against twelve isolates of E. turcicum under artificial epiphytotic conditions. Eight genotypes viz., PS45, CML165, CML459, VL1249, VL0536, SMC-5, SMC-3 and KDL 211 were found moderately resistant with disease grade ranged from 2.1-2.5. These maize genotypes possess resistance to turcicum leaf blight can be used successfully in developing high yielding early maturing varieties for high altitude temperate agro-ecologies. The fungus E. turcicum is highly variable in nature. Variability studies on pathogenicity were conducted on twelve isolates of E. turcicum on eleven putative differential maize lines. During the present study a wide pathogenic variation was observed among the twelve isolates of E. turcicum. Cluster analysis on the basis of similarity or dissimilarity in reaction types exhibited by the differential hosts, clustered the isolates into 6 pathogenic groups. The isolates belonged to higher altitudes (Kti 10, Kti11, Kti5) were found to be more aggressive as compared to the isolates of low altitude areas

FADS3 is a Δ14Z sphingoid base desaturase that contributes to gender differences in the human plasma sphingolipidome.

Sphingolipids (SLs) are structurally diverse lipids that are defined by the presence of a long-chain base (LCB) backbone. Typically, LCBs contain a single Δ4E double bond (DB) (mostly d18:1), whereas the dienic LCB sphingadienine (d18:2) contains a second DB at the Δ14Z position. The enzyme introducing the Δ14Z DB is unknown. We analyzed the LCB plasma profile in a gender-, age-, and BMI-matched subgroup of the CoLaus cohort (n = 658). Sphingadienine levels showed a significant association with gender, being on average ∼30% higher in females. A genome-wide association study (GWAS) revealed variants in the fatty acid desaturase 3 (FADS3) gene to be significantly associated with the plasma d18:2/d18:1 ratio (p = -log 7.9). Metabolic labeling assays, FADS3 overexpression and knockdown approaches, and plasma LCB profiling in FADS3-deficient mice confirmed that FADS3 is a bona fide LCB desaturase and required for the introduction of the Δ14Z double bond. Moreover, we showed that FADS3 is required for the conversion of the atypical cytotoxic 1-deoxysphinganine (1-deoxySA, m18:0) to 1-deoxysphingosine (1-deoxySO, m18:1). HEK293 cells overexpressing FADS3 were more resistant to m18:0 toxicity than WT cells. In summary, using a combination of metabolic profiling and GWAS, we identified FADS3 to be essential for forming Δ14Z DB containing LCBs, such as d18:2 and m18:1. Our results unravel FADS3 as a Δ14Z LCB desaturase, thereby disclosing the last missing enzyme of the SL de novo synthesis pathway

Trends in breeding oat for nutritional grain quality - An overview

Oat is an economically important crop and ranks sixth in world cereal production after maize, wheat, rice, barley and sorghum. It has been primarily utilized as livestock feed. However, the utilization of oats for human consumption has increased progressively, owing to its dietary and health benefits which relies mainly on the total dietary fibre and ?-glucan content, which significantly reduces postprandial blood glucose, insulin and blood lipids, especially serum total and low density lipoprotein cholesterol. Henceforth, enhancing Oat b-glucan content forhuman consumption is desirable. As it is a polygenic trait controlled mainly by genes with additive effects, phenotypic selection for greater b-glucan content would be effective for developing cultivars with elevated b-glucan contents. Oat b-glucan concentration has been found to be positively correlated with protein content and negatively correlated with oil content. ?-glucan yield (i.e., Product of grain yield and ?-glucan content) has been found to correlate positively with both grain yield (r = 0.92) and ?-glucan content (r = 0.66). Hence, this nutritional oat grain quality has been improved through selection for improved grain yield as they both increase simultaneously. Among wild accessions, A. atlantica genotypes have high ?-glucan content (2·2–11·3%) and have been used in breeding programmes for increasing the ?-glucan content of adapted elite local germplasm. Besides conventional breeding approaches, molecular breeding approaches have made possible to identify several molecular markers linked to ?-glucan rich regions across oat genome hence enabling mapping and dissection of ?-glucan rich genomic regions and accelerating the improvement in nutritional grain quality

How is it best to deliver care in acute medical units? A systematic review

The majority of medical patients presenting to hospital in the UK are cared for in acute medical units (AMUs). Such units are also increasingly present internationally. Care delivery varies across units: this review aims to examine the evidence for how best to deliver AMU care. Six electronic databases and grey literature were searched. Inclusion criteria comprised interventions applied to undifferentiated patients in AMU settings. All studies were quality assessed. A narrative approach was undertaken. Nine studies, all conducted in the UK or Ireland, evaluated 1.3 million episodes, 3617 patients and 49 staff. There was single study evidence for beneficial effects of: enhanced pharmacy care, a dedicated occupational therapy service, an all-inclusive consultant work pattern, a rapid-access medical clinic and formalized handovers. Two studies found increased consultant presence was associated with reduced mortality; one of these studies found an association with a reduction in 28-day readmissions; and the other found an association with an increased proportion of patients discharged on the day they were admitted. Three studies provide evidence of the beneficial effects of multiple interventions developed from local service reviews. Overall, the quality of the evidence was limited. This review has identified operationally relevant evidence that increased consultant presence is associated with improved outcomes of care; has highlighted the potential to improve outcomes locally through service reviews; and has demonstrated an important knowledge gap of how best to deliver AMU care. These findings have importance given the challenges acute services currently face

Genotype-independent association between vitamin D deficiency and polycystic ovarian syndrome in Lahore, Pakistan.

Both vitamin D deficiency and single nucleotide polymorphisms (SNPs) in the gene encoding the vitamin D receptor (VDR) have been widely reported to associate with susceptibility to polycystic ovarian syndrome (PCOS). A case-control study was conducted to study the influence of vitamin D status and genotpye for 24 SNPs in four genes in the vitamin D pathway (VDR, DBP, CYP27B1, CYP24A1) on PCOS. Statistical analyses were conducted to identify phenotypic and genotypic factors associated with risk of PCOS and to test for interactions between genotype and vitamin D status. PCOS was independently associated with lower age, higher body mass index, lower waist-hip ratio, vitamin D deficiency (serum 25-hydroxyvitamin D concentration <10 ng/mL), lack of outdoor exercise, increased fasting glucose and a family history of PCOS in at least one first degree relative. No statistically significant association was observed between the genotype of any SNP investigated and risk of PCOS, either as a main effect or in interaction with vitamin D status. We report a strong and independent association between vitamin D deficiency and risk of PCOS in Pakistan, that was not modified by genetic variation in the vitamin D pathway

Utilization of extracorporeal membrane oxygenation during the COVID-19 pandemic.

The ongoing outbreak of severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2, or coronavirus disease 2019 (COVID-19)] was declared a pandemic by the World Health Organization on March 11, 2020. Worldwide, more than 65 million people have been infected with this SARS-CoV-2 virus, and over 1.5 million people have died due to the viral illness. Although a tremendous amount of medical progress has been made since its inception, there continues to be ongoing research regarding the pathophysiology, treatments, and vaccines. While a vast majority of those infected develop only mild to moderate symptoms, about 5% of people have severe forms of infection resulting in respiratory failure, myocarditis, septic shock, or multi-organ failure. Despite maximal cardiopulmonary support and invasive mechanical ventilation, mortality remains high. Extracorporeal membrane oxygenation (ECMO) remains a valid treatment option when maximal conventional strategies fail. Utilization of ECMO in the pandemic is challenging from both resource allocation and ethical standpoints. This article reviews the rationale behind its use, current status of utilization, and future considerations for ECMO in critically ill COVID-19 patients

Diversity analysis of maize inbred lines using DIVA-GIS under temperate ecologies

The vagaries of Climate Change variability need to be addressed and as climatic conditions change at particular experimental sites and maize producing regions, mega-environment assignments will need to be reassessed to guide breeders to appropriate new germplasm and target environments . The development of improved germplasm to meet the needs of future generations in light of climate change and population growth is of the upmost importance . Evaluation of the inbred lines from diverse ecosystems would be effective for production of lines with resilience towards climate variability. Hence, with this objective diverse set of inbred lines sourced from all over India were characterized and were evaluated with DIVA-GIS for diversity analysis of maize inbred lines. Grid maps generated for these maize inbred lines for eleven quantitative traits indicated that these lines can be sourced from North and South India. High Shannon diversity index with maximum range of 2.17-3.0, 2.25-3.0, 2.36-3.0, 2.4-4.0, 2.0-3.0, and 2.2-3.0 were recorded for the traits viz; plant height, ear height, grain weight, grain yield, kernel row and protein content respectively indicating the high response of these traits to ecosystem. However, inbred lines were found to be diverse for all the traits except for ears plant-1 (EPP) and they have been sourced from Northern and Southern parts of India while for EPP recorded less diversity index range of 0.4-1.0 indicating source from South India. Interestingly, less diverse inbred lines for all the eleven quantitative traits have been sourced from Indogangetic plains as indicated in diversity grid maps. Maximum diversity indices were recorded for anthesis silking interval (ASI), days to silking, days to tasseling, which are in the range of 0.97-2.0, 1.528-2.0, 1.516-2.0 and 1.528-2.0 respectively. Hence, DIVA-GIS enabled identification of diverse sources from varied ecosystems which can be used for developing improved lines/ cultivars with greater resilience towards climate change

For richer or poorer in sickness for wealth: what price consumerism?

Affluence and material goods of varying types are portents of a millennium age consumer culture that encourages the masses to voluntarily participate in the need to buy, buy and buy! This trend to spend creates a purchasing fervour that preoccupies many consumers with the ongoing yearning to shop until they drop. Clever marketing tactics such as enticing smells, catchy jingles, prize-draw entries, lucrative sales, discounts and the recruitment of celebrities to advertise a range of different wares are just some of the ploys adopted by vendors and retailers to maintain the sustainability of this cycle of consumer spending. This scenario promotes what could be perceived as a never-ending desire to procure yet more products and merchandise, which can create social dilemmas such as personal debt due to, for example, impulse buying, excessive spending and unnecessary borrowing. Retailers and manufacturers are driven by a quest to sell so constantly tout their goods to tempt consumers including those with a need for personal and social respect, to take the bait in order to encourage them to keep buying. This, coupled with the rapid advances in technology over recent decades, has made it easier for consumers to shop, order, obtain and pay for their goods from the comfort of an armchair or via handheld devices, and all at a tap of a button. In essence, technology has added to, or even exacerbated, the materialistic consumer trend as witnessed across many global societies today – from the east and the west to the north and the south. But what impact does consumerism have on the well-being of humankind and, in turn, the environment? This chapter adopts a comparative approach to answer this question by exploring the implications of consumerism as a means for broadening the topic’s framework and to contribute to debates regarding consumerism, well-being, social dilemma, sustainability and techno-economics