Genetic diversity, inter-gene pool introgression and nutritional quality of common beans (Phaseolus vulgaris L.) from Central Africa

The Great Lakes region of Central Africa is a major producer of common beans in Africa. The region is known for high population density and small average farm size. The common bean represents the most important legume crop of the region, grown on over a third of the cultivated land area, and the per capita consumption is among the highest in the world for the food crop. The objective of this study was to evaluate the genetic diversity in a collection of 365 genotypes from the Great Lakes region of Central Africa, including a large group of landraces from Rwanda as well as varieties from primary centers of diversity and from neighboring countries of Central Africa, such as the Democratic Republic of Congo and Uganda, using 30 fluorescently labeled microsatellite markers and automated allele detection. In addition, the landraces were evaluated for their seed iron and zinc concentration to determine if genetic diversity influenced nutritional quality. Principal coordinate and neighbor-joining analyses allowed the separation of the landraces into 132 Andean and 195 Mesoamerican (or Middle American) genotypes with 32 landraces and 6 varieties intermediate between the gene pools and representing inter-gene pool introgression in terms of seed characteristics and alleles. Genetic diversity and the number of alleles were high for the collection, reflecting the preference for a wide range of seed types in the region and no strong commercial class preference, although red, red mottled and brown seeded beans were common. Observed heterozygosity was also high and may be explained by the common practice of maintaining seed and plant mixtures, a coping strategy practiced by Central African farmers to reduce the effects of abiotic and biotic stresses. Finally, nutritional quality differed between the gene pools with respect to seed iron and zinc concentration, while genotypes from the intermediate group were notably high in both minerals. In conclusion, this study has shown that Central African varieties of common bean are a source of wide genetic diversity with variable nutritional quality that can be used in crop improvement programs for the region

Lutter contre les carences en micronutriments au Cameroun par la biofortification du haricot commun

La biofortification est un processus par lequel la valeur nutritionnelle (vitamines et/ou minéraux) d’une culture vivrière est améliorée par le processus de sélection conventionnelle. L’amélioration de nouvelles variétés biofortifiées repose sur la sélection génétique pour développer une plante avec des teneurs plus élevées en protéines, vitamines et les minéraux, notamment le fer, le zinc, la provitamine A, etc,. Onze haricots améliorés riches en fer et en zinc ont été introduits sur le marché au Cameroun à la suite d’une récente analyse nutritionnelle portant sur plus de 30 variétés de haricots communs (variétés locales et variétés introduites). L’adoption et la diffusion de ces variétés nouvellement identifiées avec une grande concentration en fer et en zinc contribuera à lutter contre les carences en fer et en zinc chez les femmes et les enfants de moins de cinq ans. La culture et la vente du haricot amélioré permettront également d’améliorer les revenus et la sécurité alimentaire des ménages. Le haricot commun est la légumineuse la plus cultivée et la plus consommée, et une des sources de protéine plus accessible au Cameroun. La promulgation de ces nouvelles variétés de haricot riche en fer et en zinc et leur adoption ultérieure dans les régimes alimentaires des ménages constitue une intervention peu coûteuse pour lutter contre les problèmes de santé publique liés aux carences en fer et en zinc au sein de la population

Addressing micronutrient deficiency in Cameroon through common bean biofortification

Biofortification is a process through which the nutritional value – vitamins or minerals of a food crop is enhanced through conventional breeding. Through biofortification, vitamins and minerals such as iron, zinc, provitamin A etc. are enhanced. Eleven high iron and zinc beans have been released in Cameroon after a recent nutritional screening of more than 30 common bean varieties (local landraces and improved bean varieties). The adoption and dissemination of these newly identified high iron and zinc varieties will contribute to addressing iron and zinc deficiency among women and children under five. Growing and selling beans will also ensure income and food security for the household. Common beans are the most grown and consumed legume and affordable source of protein in Cameroon. The release of high iron and zinc beans and subsequent incorporation into the household diets is a cost-effective intervention in addressing health disorders related to inadequate intake of iron and zinc

Impact of foliar application of zinc and magnesium aminochelate on bean physiology and productivity in Ghana

Foliar application of fertilizers can guarantee nutrient availability to beans, leading to higher yield and seed quality. Different approaches including glycine have been used to improve mineral nutrient status of plants toward safer products and improved human health. However, limited research has been undertaken to understand the response of beans to amino Zn and Mg foliar fertilizer application in Ghana. )is study was conducted to investigate the effect of zinc, magnesium, and combined zinc and magnesium foliar fertilizer application on two improved common bean (Phaseolus vulgaris L.) varieties locally referred to as Adoye and Nsroma in the forest (Fumesua) and forest-savannah transition (Akumadan) agro-ecological zones of Ghana during the 2018 and 2019 cropping seasons.)etreatments were arranged in split-plot design with the two improved common bean varieties as the main plot, and foliar fertilizer options (zinc, 200 g/ha; magnesium, 224 g/ha; combined zinc and magnesium, 100 g/ha Zn and 112 g/ha Mg) and water spray (control) as the subplot treatments. )e zinc and combined zinc and magnesium treatments had similar and significantly (P ≤ 0.05) higher plant height of 37.1 cm and 38.7 cm compared to the control and magnesium treatments. )e results also showed that chlorophyll content was approximately 15.6% higher in plants treated with zinc plus magnesium compared to the other treatments. Similarly, stomatal conductance was significantly (P ≤ 0.05) increased by 35.6% with zinc plus magnesium treatment relative to the other treatments. )eimproved chlorophyll content and stomatal conductance in those treatments resulted in ∼55.3–80.6% increase in crop biomass and seed yield. Crop performance parameters such as plant height, canopy spread, and chlorophyll content were significantly higher (P ≤ 0.05) at Akumadan, resulting in a greater seed yield of 1486.2 kg/ha compared to 1365.3 kg/ha at Fumesua. Combined application of zinc and magnesium appears to be a potential soil improvement strategy for common bean production in tropical soil environment of Ghana

Prospects of snap beans (Phaseolus vulgaris L.) production and commercialization in Benin

BackgroundVegetables and fruits are highly recommended in diets because of their nutritional importance. Among those, leguminous vegetables are more important, for low-income countries, because of their protein, mineral contents and potential to increase food security and income. In Benin, snap beans (Phaseolus vulgaris L.) are the most consumed leguminous vegetables; however, their production is declining, driving the need to understand the current status of its industry to propose solutions for the revival of the sector. This paper assessed the production system, market value, marketing channels, seed systems, and the constraints associated with Benin’s snap bean production from a gender lens.MethodsA semi-structured interview was conducted with 602 bean producers and traders, randomly selected from 12 major vegetable-producing areas across Benin.ResultsThe study found a drastic decline in the production of snap beans, with more than 60% abandonment over the last decade. As a consequence, Benin gets supplied through importations, with the highest importation flow coming from Togo (51%), followed by Burkina Faso (25%), and Ghana (12%). Only 13% of the beans traded are locally produced. The leading causes of the decline were pests and diseases that affected the crops’ yield and quality, causing the local produce to be less valued than the imported ones. Women are heavily involved in marketing but cannot expand their business due to low production and high importation.DiscussionThe study recommends that integrated pest management (IPM) and new varieties with tolerance to major pests and diseases be developed to address market demand and producers trained in agronomic practices

Exploiting Interspecific Genetic Variability for Improving Common bean for higher productivity on soils presenting biotic and abiotic stresses

Biotic and abiotic stresses often occur in the same field of rural poor farmer households in tropical countries resulting in heavy losses of common bean yields. To improve resistance of common beans, sensitive Phaseolus vulgaris (SER16) was crossed to resistant P. coccineus (G35346-3Q) to create 94 F5:6 recombinant inbred lines (RILs) of the pedigree SER16♀ x (SER16♀ x G35346-3Q♂). The objectives of this study were to (i) identify potential parents for resistance to Al, drought and Fusarium root rot among 11 bean genotypes, (ii) to evaluate 94 F5:6 Recombinant Inbred Lines (RILs) of the cross SER 16♀ x (SER 16♀ x G35346-3Q♂) both for their resistance to Al and /or drought, (iii) to evaluate RILs for resistance to Fusarium root rot, and (iv) to identify QTL for resistance to these stresses. RILs were characterized in greenhouse for resistance to Al using a hydroponic screening employing a nutrient solution with or without 20 μM Al , to Al-toxic acid soil with high Al (HAl) and low Al (LAl) saturation, to terminal drought simulation with and without progressive soil drying, to combined stresses of Al and terminal drought in 80 cm long soil cylinder system, and to Fusarium root rot using inoculated perlite soil and sand (2:1). Two field studies were also carried on in Colombia under rainfed and irrigated conditions in Palmira, and high Al saturated acid soil in Santander of Quilichao. Our studies confirmed the superiority in Al response of Andean common beans in greenhouse trials compared to Middle American type for several root traits. Each screening method of our Al greenhouse experiments permitted an evaluation of different aspects of root traits. The two parents were virtually equal for tap root elongation rate at 24 h in the 20 μM Al treatment at about 1.4 mm h-1 while progenies ranged from less than 1-1.75 mm h-1. The correlation between leaf area and total root length was highly significant under high Al saturation (r = 0.70***) for HAl-acid soil. Two genotypes (ALB88 and ALB 91) emerged as strong multiple trait lines for the two abiotic stresses. Fusarium root rot induced root growth inhibition as high as 80.8% for the susceptible ALB 5, while resistant RILs (ALB45, ALB41, ALB126, ALB84, ALB49, ALB34, ALB88 and ALB85) didn`t show any inhibition . Seed yield under drought stress conditions was positively associated to 100-seed weight both under irrigated field (r = 0.28**) and rainfed field (r = 0.36***), and negatively associated to days to maturity (DTM) (r = - 0.36***) in field evaluation in Al-toxic acid soil in Quilichao (Colombia). QTLs for important traits including root characteristics under high Al , grain yield and yield components for drought and high Al saturation soil were identified. The use of both soil and hydroponic system, and field could contribute to evaluation of breeding materials to identify genotypes that combine Al resistance with acid soil tolerance, drought and root rot tolerance.Les contraintes biotiques et abiotiques du haricot commun agissent souvent ensembles dans des exploitations des fermiers pauvres des pays tropicaux, et entrainent de lourdes pertes de rendements. Dans le but d`améliorer la résistance à ces stresses, l`hybridation interspécifique en backcross de SER16♀ x (SER16♀ x G35346-3Q♂) a été réalisé pour produire 94 lignées hybrides de la génération BC F5:6. Les objectifs de ce travail consistaient à (i) identifier les parents potentiels parmi 11 genotypes de Phaseolus, (ii) évaluer la performance de ces hybrides pour la résistance à la toxicité aluminique et/ou à la sécheresse, (iii) à la pourriture racinaire causée par Fusarium solani, et (iv) identifier des gènes QTLs responsables de la résistance à ces stresses. L`évaluation de ces hybrides pour la résistance à la toxicité aluminique a été réalisée en serre en hydroponie avec présence ou absence des ions Al+3 (20 μM Al) et en tube cylindrique avec sol acide à saturation faible et élevée d`Al, à la sécheresse, à la combinaison du stress hydrique et d`Aluminium, et enfin pour la résistance aux maladies racinaires dues au Fusarium. Des essais en champs ont été réalisés pour la sélection des hybrides en structure irriguée et non-irriguée à Palmira, et en sol acide et saturation elevée en Al à Santander de Quilichao. Notre étude confirme la supériorité de la résistance à la toxicité aluminique observée chez le haricot du pool génique Andine par rapport au pool Mésoaméricain pour la plupart des caractéristiques des racines. Les essais en serre ont démontré que chaque méthode d`évaluation permet d`étudier un aspect différent du système racinaire. Alors que leur hybrides ont montré une vitesse de croissance de la racine principale (en 24h sous 20μM) qui varie de 1 à 1.75 mm h-1, les 2 parents restent á un même niveau (à environ 1.4 mm h-1). Une bonne corrélation a été observée entre la surface foliaire et la longueur totale des racines en sol acide avec saturation élevée en Al (r = 0.70***). Les hybrides (ALB88 et ALB 91) ont été sélectionnés comme des lignées aux caractéristiques multiples vis-à-vis des deux stresses abiotiques. L`inhibition de la croissance des racines due aux maladies racinaires a été très élevé pour l`hybride sensible ALB5 (80.8 %) alors que aucune inhibition n`a été observée chez les hybrides résistant (ALB45, ALB41, ALB126, ALB84, ALB49, ALB34, ALB88 and ALB85). Le rendement en graines se retrouve positivement associé au poids de 100 graines en structure non-irriguée (r = 0.36***) et négativement associé avec le nombre de jours á la maturité en sol acide et saturé en Al (r = -0.36***). Des gènes QTLs pour certains caractères important pour les racines, le rendement en graines et quelques caractéristiques qui lui sont associés ont été identifiés. Les essais en serre et en champs devraient contribuer á l`identification des génotypes résistant á la toxicité aluminique, á la sécheresse, et aux maladies racinaires.Fighting drought and aluminium toxicity: Integrating functional genomics, phenotypic screening and participatory evaluation with women and small-scale farmers to develop stress-resistant Common bean and Brachiaria for the Tropic

Consumer Acceptance of Biofortified Iron Beans in Rural Rwanda: Experimental Evidence

We examine consumer acceptance of two iron bean varieties in Rwanda: red iron bean (RIB) and white iron bean (WIB). Using the Becker-DeGroot-Marschak mechanism, we investigate the effect of (1) nutrition information; (2) information frame (information emphasizing negative consequences of not having enough iron in diets versus information emphasizing benefits), and (3) the frequency of providing the information, on consumer willingness to pay (WTP) for iron bean varieties. Results indicate that in the absence of information about their nutritional benefits, consumers are willing to pay a large premium for RIB, but not for WIB, relative to the local variety. Nutrition information has a positive effect on the premium for each of the iron bean varieties. We find that the way in which the information is framed has no significant effect on this premium, whereas provision of the information three times versus once significantly increases WTP for WIB

Phenotypic evaluation of interspecific recombinant inbred lines (RILs) of Phaseolus species for their resistance to aluminum and tolerance to aluminum-toxic acid soil under greenhouse conditions

Aluminium (Al) toxicity limits common bean productivity in acid soil regions of the tropics. To improve Al resistance of common bean, Al-sensitive Phaseolus vulgaris (SER16) was crossed to Alresistant P. coccineus (G35346-3Q) to create 94 F5:6 recombinant inbred lines (RILs) of the pedigree SER16 9 (SER16 9 G35346-3Q). RILs were characterized for resistance to Al in a hydroponic system with 0 and 20 lM Al in solution, and for shoot and root growth response to Al-toxic infertile acid soil in 75 cm long soil cylinder system using an oxisol of low Al- (12.5%; pH 4.6; fertilized) and high Al-saturation (77%; pH 4.1; unfertilized). G35346-3Q increased its taproot elongation rate by 3.5% between 24 and 48 h under 20 lM Al in solution, while the best RIL, Andean genotype ICA Quimbaya, and sensitive genotype VAX1 expressed reductions of 2.6, 12.5, and 69.5%, respectively. In the acid soil treatment the correlation between leaf area and total root length was highly significant under high Al saturation (r = 0.70***). Genotypes that were Al resistant in the hydroponic system were not necessarily tolerant to Al-toxic acid soil conditions based on shoot and root growth responses. Phenotypic evaluation using both systems allows the identification of genotypes with Al resistance combined with acid soil adaptation. Two genotypes (ALB88 and ALB91) emerged as lines with multiple traits. Results suggest that inheritance of Al resistance and acid soil tolerance in G35346-3Q is complex. Results from this work will be useful for identification of molecular markers for Al resistance in Phaseolus species and to improve acid soil adaptation in common bean

Heat Stress Tolerance: A Prerequisite for the Selection of Drought- and Low Phosphorus-Tolerant Common Beans for Equatorial Tropical Regions Such as Ghana

Forty common bean accessions of multiple genetic background trait attribution regarding drought tolerance were selected based on mean yield performance from an earlier field test evaluation conducted using augmented RCBD. The various bean genotypes were further evaluated with phosphorus and water treatment interactions at two different levels for each factor. The experiment was conducted in a 2 × 2 × 40 factorial using RCBD with three replications under screen-house conditions at the CSIR-Crops Research Institute, Kumasi-Ghana. The objective was to select drought- and low phosphorus-tolerant common bean genotypes; which are suitable for tropical climatic conditions. The results showed that common bean with drought and heat trait tolerance survived, developed flowers and podded with seeds to physiological maturity, whilst genotypes with no heat trait tolerance had impaired reproductive structural development and growth disruption; thus, flowers could not develop into pods with seeds. This reproductive developmental anomaly was due to prevailing average daytime and nighttime high temperatures of 35.45 °C and 29.95 °C, respectively, recorded during the growth period, which reduced pollen fertility. Among the 478 experimental bean plants (two plants were missing) analyzed, 141 (29.5%) did not flower, 168 (35.18%) had their pods dropped whilst 99 (20.7%) podded with seeds to achieve physiological maturity. The podded-seed bean genotypes were of the SEF-line pedigrees, which were shown to be heat and drought-tolerant. Meanwhile, bean accessions with SMC, SMN and SMR code prefixes did not pod into seed despite possessing drought-tolerant traits. The effects of interactions between phosphorus and water treatments on the root characteristics of drought-tolerant common bean were as follows: root length, root surface area, average root diameter and root volume growth extensions doubled dimensionally under optimum conditions (P2W2) compared to stressed conditions (P1W1). The results from the present study identified four SEF-bean genotypes, namely, SEF15, SEF 47, SEF 60 and SEF 62, as superior yield performers, even under low soil phosphorus and in extreme high temperature conditions. Therefore, breeding for the selection of drought- and low-P-tolerant common bean for tropical agro-ecological environments must also consider concomitant heat stress tolerance

Review of Policies and Frameworks on Climate Change, Agriculture, Food and Nutrition Security in Eastern Africa: Ethiopia, Kenya, Rwanda, Tanzania, and Uganda

This is a review of policies, strategies, and frameworks related to climate change, agriculture, food, and nutrition security in Ethiopia, Kenya, Rwanda, Tanzania, and Uganda. The five focus countries have made tremendous efforts to strengthen the enabling environment for addressing climate change and improving agricultural productivity and food and nutrition security by putting the appropriate policies, frameworks, and strategies in place. This policy review was based on document review and expert consultations in each country and specifically: i) analyzed the policy integration between climate change and agriculture and food and nutrition security for each country, and ii) examined the institutional landscape for climate change, agriculture, food, and nutrition security Eastern Africa. There are deliberate and proactive efforts to strengthen the integration and coherence in the more recent policies and frameworks for climate change, agriculture, food, and nutrition security. Most East African countries have prioritized agricultural productivity, food availability, and climate change adaptation in most of their policies and frameworks, with a narrow focus on food utilization and climate change mitigation. However, little effort has been made to integrate budgeting and planning, implementation and monitoring processes, bringing together climate change and agriculture, and food and nutrition security. There is a need to strengthen the linkages and coordination between climate change and agriculture, food and nutrition stakeholders to improve efficiency and reduce overlaps in implementing programs and projects