Yield and stability of new cowpea varieties in Zimbabwe

Cowpea ( Vigna unguiculata [L.] Walp) is highly nutritious and fits well in smallholder crop-livestock farming systems of sub-Saharan Africa. Newly developed cowpea varieties need to be assessed for grain yield performance and stability across environments. Furthermore, a comprehensive understanding of the test environments is crucial in rationalising resources for breeding programmes. The objective of this study was to identify high yielding and stable cowpea genotypes, and determine the ideal (representative and discriminating) testing environments for cowpea in Zimbabwe. Fifteen cowpea genotypes were evaluated at 5 locations, for 2 years under rain-fed conditions. Combined analysis of variance for grain yield across locations and years showed highly significant (P < 0.001) genotype x environment interaction (GE). The variance component due to GE was 6 times larger than that of genotypes. Genotype plus GE biplot showed that environments studied were actually in one mega-environment; and Harare Research Station (HRS) was identified as desirable discriminating and representative environment. Genotypes G1, G11 and G3 were high yielding and more stable than the check varieties, G4 (CBC2) and G7 (CBC3). These genotypes are suitable for release; while HRS is recommended for culling inferior genotypes during early generation testing.Le ni\ue9b\ue9 ( Vigna unguiculata [L.] Walp) est hautement nutritif et bien adapt\ue9 au syst\ue8me de production associant culture-animal de l\u2019Afrique Sub-Saharienne. Des vari\ue9t\ue9s nouvellement d\ue9velopp\ue9esont besoin d\u2019\ueatre \ue9valu\ue9es pour leur performance en grain et leur stabilit\ue9 \ue0 travers des environnements. De plus, une bonne ma\ueetrise des environnements \ue0 tester en rationalisant les ressources pour les programmes d\u2019am\ue9lioration g\ue9n\ue9tique. L\u2019objective de cette \ue9tude \ue9tait d\u2019identifier les g\ue9notypes \ue0 haut rendement et stables, et de d\ue9terminer les environnements id\ue9aux (repr\ue9sentatifs et discriminants) pour le ni\ue9b\ue9 au Zimbabwe. Quinze g\ue9notypes du ni\ue9b\ue9 ont \ue9t\ue9 \ue9valu\ue9s dans 5 localit\ue9s, pendant deux ans sous des conditions pluviales. Analyse combin\ue9e de variance pour le rendement en grain \ue0 travers les\ua0localit\ue9s et ann\ue9es ont montr\ue9 une interaction g\ue9notype x environnement (GE) significative (P < 0.001). La composante de variance due \ue0 GE \ue9tait 6 fois plus grande que celle des g\ue9notypes. G\ue9notype plus GE biplot a montr\ue9 que les environnements \ue9tudi\ue9s \ue9taient \ue9videmment dans un m\ue9ga-environnement\ua0; et la station de recherche de Harare (HRS) \ue9tait identifi\ue9e comme un environnement d\ue9sirable discriminant et repr\ue9sentatif. Les g\ue9notypes G1, G11 et G3 \ue9taient \ue0 haut rendement et plus stable que les vari\ue9t\ue9s contr\uf4les, G4 (CBC2) et G7 (CBC3). Ces g\ue9notypes sont les plus appropri\ue9s pour d\ue9livrance, alors que HRS est recommand\ue9e pour faible s\ue9lection dans la g\ue9n\ue9ration pr\ue9coce

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Genome-wide association mapping for component traits of drought tolerance in dry beans (Phaseolus vulgaris L.)

Understanding the genetic basis of traits of economic importance under drought stressed and well-watered conditions is important in enhancing genetic gains in dry beans (Phaseolus vulgaris L.). This research aims to: (i) identify markers associated with agronomic and physiological traits for drought tolerance and (ii) identify drought-related putative candidate genes within the mapped genomic regions. An andean and middle-american diversity panel (AMDP) comprising of 185 genotypes was screened in the field under drought stressed and well-watered conditions for two successive seasons. Agronomic and physiological traits, viz., days to 50% flowering (DFW), plant height (PH), days to physiological maturity (DPM), grain yield (GYD), 100-seed weight (SW), leaf temperature (LT), leaf chlorophyll content (LCC) and stomatal conductance (SC) were phenotyped. Principal component and association analysis were conducted using the filtered 9370 Diversity Arrays Technology sequencing (DArTseq) markers. The mean PH, GYD, SW, DPM, LCC and SC of the panel was reduced by 12.1, 29.6, 10.3, 12.6, 28.5 and 62.0%, respectively under drought stressed conditions. Population structure analysis revealed two sub-populations, which corresponded to the andean and middle-american gene pools. Markers explained 0.08-0.10, 0.22-0.23, 0.29-0.32, 0.43-0.44, 0.65-0.66 and 0.69-0.70 of the total phenotypic variability (R2) for SC, LT, PH, GYD, SW and DFW, respectively under drought stressed conditions. For well-watered conditions, R2 varied from 0.08 (LT) to 0.70 (DPM). Overall, 68 significant (p < 10-03) marker-trait associations (MTAs) and 22 putative candidate genes were identified across drought stressed and well-watered conditions. Most of the identified genes had known biological functions related to regulating the response to drought stress. The findings provide new insights into the genetic architecture of drought stress tolerance in common bean. The findings also provide potential candidate SNPs and putative genes that can be utilized in gene discovery and marker-assisted breeding for drought tolerance after validation.Bruce Mutari, Julia Sibiya, Admire Shayanowako, Charity Chidzanga, Prince M. Matova, Edmore Gasur