Variability in cooking time, iron and zinc content in common bean (Phaseolus Vulgaris L.) genotypes

Prolonged cooking time leads to structural changes at the grain cellular level, resulting in loss of nutrients such as iron (Fe) and zinc (Zn) which are among the main nutrients important in addressing micronutrient malnutrition. The aim of this study was to evaluate the diversity of cooking time, Fe and Zn content in a total of 152 common bean (Phaseolus vulgaris) genotypes from around Eastern Africa, in order to identify short cooking genotypes with high Fe and Zn content. Field trials were conducted at CIAT-Uganda research station over two seasons in 2016. Cooking time was estimated using an automated Mattson cooker at CIAT-Uganda while Fe and Zn content was determined using XRF analysis at Rwanda Agricultural Board (RAB) in Rubona. A wide variability was evident from the test genotypes both for cooking time and mineral concentration. Cooking time exhibited a continuous distribution ranging from 35-100 minutes for the first season and 43–122 minutes for the second season. Seventy-three percent of the test genotypes had Fe levels higher than the low Fe check, CAL 96 (55mg/kg) which is popularly known as ‘Nambale’ and a popular commercial variety in Uganda. A total of 15 genotypes (Amahunja, Awash melka, Bihogo, CAB 2, ECAPAN021, G858, Icaquimbaya, KK20, NABE12C, NABE4, NABE6, ROBA-1, RWR1873, RWV3006) were consistent in short cooking time for the two seasons and had a Fe content above the low Fe check (CAL96 – 55mg/kg). A high correlation (r = 0.71) was observed between Fe and Zn whereas a low correlation between cooking time and Fe (r = -0.04) and Zn (r = 0.04) was observed. Great variability was evident for both traits indicating possible improvement by breeding and thus the possibility of having short cooking common bean genotypes with high Fe and Zn content

Development, promotion and dissemination of improved Fusarium wilt resistant pigeon pea lines in drought prone areas of Uganda

Pigeon Pea (Cajanus cajan) remains a relatively untapped food legume crop in Uganda and in many parts of Africa mainly due to lack of promotion and availability of varieties that meet producer and consumers needs. The crop is a rich source of protein, fixes nitrogen in the soil and is tolerant to drought conditions. This makes it an ideal crop for the semi-arid areas of Africa. This project is using a participatory breeding approach to develop and promote consumer/market preferred pigeon pea varieties resistant to Fusarium wilt disease (Fusarium udum) and drought among farmers in northern Uganda. To do this, a collection of landraces and elite materials from Uganda, Malawi and ICRISAT is being screened for farmer desired qualities. Promising lines will be analyzed for performance under Fusarium wilt infection and drought, and thereafter selected lines will be entered into a breeding program. All research activities have been designed as part of two students' M.Sc. thesis research, involving a Ugandan and a Malawian studen

PREVALENCE OF ANGULAR LEAF SPOT DISEASE AND SOURCES OF RESISTANCE IN COMMON BEAN IN EASTERN DEMOCRATIC REPUBLIC OF CONGO

Angular leaf spot ( Pseudocercospora griseola Crous U, Brown) is one of the most important diseases hindering common bean ( Phaseolus vulgaris L.) production in the Great Lakes Region of Africa, including the Democratic Republic of Congo. The disease causes extreme yield losses, estimated at 384.2 tonnes per year, in Sub-Saharan Africa. Little is known about the distribution, severity and incidence of the disease and the effect of agronomic practices and environmental factors on the disease prevalence in the country to facilitate interventions. A field survey was conducted during two crop seasons, February to June and September to January, in two main beans growing zones of eastern DRC namely; sub-humid highland and sub-humid mid altitude at low latitudes, in South and North Kivu, respectively. Severity and incidence of angular leaf-spot and other occurring diseases were assessed on common bean plants in farmers\u2019 fields. Angular leaf spot in these fields had an average severity index (PSI) of 49.9%. PSI was significantly different (P<0.05) between districts and seasons. Using multiple regression analysis, independent variables: growth stage, cropping system, districts and altitude were shown to have significant influence on the observed PSI (P<0.05) with R2 = 96.2%. The highest severity (PSI=59.7%) was observed in Kabare district, and the lowest in Uvira district (PSI=39.5%). Screening of a set of 37 released common bean varieties in DRC using virulent Andean and Mesoamerican isolates identified four resistant bean varieties; ARA 4, COD MLV 059, MLV 224/94B, LSA 144 and Mexico 54. Some of these varieties possess useful traits, in addition to acceptable seed market class, and are hence recommended as suitable parents for ALS resistant variety development and promotion in ALS prone environments.La tache angulaire ( Pseudocercospora griseola Crous U, Brown) est l\u2019une des maladies les plus importantes qui entravent la production de haricot commun ( Phaseolus vulgaris L.) dans la r\ue9gion des Grands Lacs d\u2019Afrique, y compris la R\ue9publique D\ue9mocratique du Congo. La maladie provoque des pertes de rendement extr\ueames, estim\ue9es \ue0 384.2 tonnes par an en Afrique Sub-Saharienne. Ily a encore peu de connaissance sur la distribution, la gravit\ue9 et l\u2019incidence de la maladie et l\u2019effet des pratiques agronomiques et des facteurs environnement aux sur la pr\ue9valence de la maladie dans le pays pour faciliter les interventions. Une enqu\ueatesur le terrain a \ue9t\ue9men\ue9e pendant deux saisons de r\ue9colte, de F\ue9vrier \ue0 Juin et de Septembre \ue0 janvier, dans deux zones principals de culture de haricots de l\u2019est de la RDC, \ue0 savoir: Sous-humides de haute altitude et sous-humides \ue0 basse altitude, au Sud et au Nord-Kivu. La gravit\ue9 et l\u2019incidence de la tache angulaire des feuilles et d\u2019autres maladies ont \ue9t\ue9 \ue9valu\ue9es sur les plants de haricots dans les champs des agriculteurs. Ces champs \ue9taient infest\ue9s par la maladie, avec unindice de gravit\ue9 moyen (IPS) de 49.9%. PSI \ue9tait significativement diff\ue9rent (P <0.05) entre districts et saisons. En utilisant l\u2019analyse de r\ue9gression multiple, les variables ind\ue9pendantes: stade de croissance, syst\ue8me de culture, districts et altitude ont montr\ue9 une influence significative sur le PSI observ\ue9 (P <0.05) avec R2 = 96.2%. La s\ue9v\ue9rit\ue9 plus \ue9lev\ue9e (PSI = 59.7%) a \ue9t\ue9 observ\ue9e dans le district de Kabare et la plus faible dans le district d\u2019Uvira (PSI = 39,5%). La s\ue9lection d\u2019un lot de 37 vari\ue9t\ue9s de haricot distribu\ue9es en RDC utilisant des isolats virulents Andins et M\ue9soam\ue9ricains a permis d\u2019identifier quatre vari\ue9t\ue9s de haricots r\ue9sistants; ARA 4, COD MLV 059, MLV 224 / 94B, LSA 144 et Mexique 54. Certaines de ces vari\ue9t\ue9s pr\ue9sentent des traits utiles en plus de son acceptabilit\ue9 sur lemarch\ue9 des semences, et sont donc recommand\ue9s comme des parents appropri\ue9s pour le d\ue9veloppement et la promotion des vari\ue9t\ue9s r\ue9sistantes ALS

Effect of intermittent drought on phenotypic traits of F5 RIL Andean intra-gene cross population (BRB 191 X SEQ 1027) of common bean

Drought is a major constraint to common bean ( Phaseolus vulgaris L.) production in East Africa, where irrigation for the crop is very uncommon. The objective of this study was to identify drought tolerant lines and phenotypic traits underlying drought tolerance among 128 F5 recombinant inbred lines (RILs), derived from intra gene pool population, between drought tolerant BRB 191 (source of bc-3) and SEQ 1027. The population was evaluated with eight experimental checks that included BAT 477, CAL 96, DAB 441, DAB 494, and Diacol Calima, NABE 4, SCR 9 and SEQ 1003. A total of 20 phenological, morphological and physiological shoot traits were evaluated, under drought and non-stress conditions, in the field for 2 years (2014 and 2015) at Kawanda in Uganda. New sources of drought tolerance, and previously identified sources of drought tolerance in common bean (BAT 477, DAB 441 and DAB 494), were confirmed based on their superior geometric means and low drought susceptibility. Drought stress in the field significantly affected all measured traits, except harvest index and stem dry weight reduction (P<0.001). Drought significantly reduced yield, yield components and pod harvest index (P<0.01). However, chlorophyll content, canopy temperature, stem dry mass reduction, and 100 seed weight remained stable under season by genotype by water regime treatment interactions (S x G x T). The stability of these traits highlighted their usefulness in selecting for drought tolerance across different environments. Furthermore, pod partitioning index (PPI), harvest index (HI), chlorophyll content and stem dry weight reduction also remained stable under G x T effects. Significant correlations (P<0.001) were maintained between HI and PPI with seed yield under drought stress in field conditions, indicating that photosynthate remobilisation increases yield under drought stress conditions.La s\ue9cheresse est une contrainte major \ue0 la production du haricot commun ( Phaseolus vulgaris L.) en Afrique de l\u2019Est, o\uf9 l\u2019irrigation pour la culture est tr\ue8s rare. L\u2019objectif de cette \ue9tude a \ue9t\ue9 d\u2019identifier les lign\ue9es tol\ue9rantes \ue0 la s\ue9cheresse et les traits ph\ue9notypiques contr\uf4lant la tol\ue9rance \ue0 la s\ue9cheresse parmi les 128 F5 de lign\ue9es consanguines recombinantes, d\ue9riv\ue9es d\u2019une population intra-g\ue8ne de la r\ue9gion andine, entre la lign\ue9e tol\ue9rante \ue0 la s\ue9cheresse BRB191 (source du bc-3) et SEQ 1027. La population a \ue9t\ue9 \ue9valu\ue9e avec huit contr\uf4les exp\ue9rimentaux comprenant BAT 477, CAL 96, DAB 441, DAB 494, et Diacol calima, NABE 4, SCR 9 et SEQ 1003. Un total de 20 traits phr\ue9nologiques, morphologiques et physiologiques a \ue9t\ue9 \ue9valu\ue9, sous les conditions de stress hydrique, dans le champ pour 2 ans (2014 et 2015) \ue0 Kwanda en Uganda. De nouvelles sources de tol\ue9rance, et des sources de tol\ue9rance pr\ue9c\ue9demment identifi\ue9es dans le haricot commun (BAT 477, DAB 441 et DAB 494), ont \ue9t\ue9 confirm\ue9es sur la base des moyens de sup\ue9riorit\ue9 g\ue9om\ue9triques et de susceptibilit\ue9 de faible s\ue8cheresse. Le stress hydrique dans le champ a significativement affect\ue9 tous les traits mesur\ue9s, \ue0 l\u2019exception de l\u2019indice de r\ue9colte et la r\ue9duction du poids sec de la tige (P<0,001). La s\ue9cheresse a significativement r\ue9duit le rendement, les composantes du rendement et l\u2019indice de la r\ue9colte de la gousse (P<0.01). Toutefois, la temp\ue9rature de la canop\ue9e, la r\ue9duction du poids sec de la tige, et le poids de 100 graines sont rest\ue9s stables sous le traitement de l\u2019interaction entre la saison x g\ue9notype x r\ue9gime d\u2019eau de m\ueame que l\u2019interaction entre le g\ue9notype x le traitement (G X T) (P<0,001). La stabilit\ue9 de ces traits a montr\ue9 leur utilit\ue9 dans la s\ue9lection pour la tol\ue9rance \ue0 la s\ue9cheresse \ue0 travers les diff\ue9rents environnements. De plus, l\u2019indice du partitionnement de la gousse (PPI), l\u2019indice de r\ue9colte (HI), la teneur en chlorophylle et la r\ue9duction du poids sec de la tige sont rest\ue9s \ue9galement stables sous les effets de G x T. Des corr\ue9lations significatives (P<0,001) ont \ue9t\ue9 maintenues entre HI et PPI avec le rendement en graine sous le stress hydrique dans les conditions de champ, indiquant la viabilit\ue9 de la remobilisation de la photosynthate dans l\u2019augmentation du rendement potentiel sous les conditions de stress hydrique

AGRONOMIC QUALITIES OF GENETIC PYRAMIDS OF COMMON BEAN DEVELOPED FOR MULTIPLE-DISEASE-RESISTANCE

Multiple co-infections by different pathogens on common bean ( Phaseolus vulgaris L.) affect its productivity and cause complete crop loss in susceptible varieties. Therefore, gene pyramiding using marker assisted selection (MAS) and backcrossing, provide alternative cost-effective control measures to bean diseases. However, in the process of developing pyramids, linkage drags were likely to affect the qualities of progeny lines, hence, special attention was paid to this situation. The objective of this study was thus to assess the agronomic qualities of advanced genetic pyramids developed from a four-way cross for multiple disease resistance. The disease resistance genes (R) pyramided from four parents were: Co42 and Co-5 from G2333; Phg-2 from MEX54; Pythium ultimum Dennis from MLB49-89A and I & bc3 from MCM5001. The progeny lines were planted in an incomplete block design, and replicated thrice for two seasons (2015A and 2015B) in fields at CIAT, Kawanda in Uganda. Agronomic traits were highly heritable (0.6), except number of pods per plant (< 0.3). Backcrossing generated high-yielding bean lines, with 270 - 290 seed per plant and early maturity (95-100 days). Nine superior lines with desirable qualities, such as earliness (95 days), high seed rate (290 seeds per plant), and climbing ability, were obtained. Pyramiding R genes did not affect yield traits, except time to flowering and number of flower buds per plant due to transgressive segregation.Les co-infections multiples par de diff\ue9rents pathog\ue8nes sur le haricot commun ( Phaseolus vulgaris L.) affectent sa productivit\ue9 et causent la perte totale des vari\ue9t\ue9s susceptibles de la culture. Par cons\ue9quent, la pyramide des g\ue8nes en utilisant la s\ue9lection assist\ue9e par des marqueurs (MAS) et le r\ue9trocroisement, fournissent des mesures alternatives de contr\uf4le moins ch\ue8res des maladies du haricot. N\ue9anmoins, dans le processus du d\ue9veloppement des pyramides, les poids des liaisons affectent probablement les qualit\ue9s des lign\ue9es de prog\ue9nitures, de ce fait, une attention particuli\ue8re \ue9tait port\ue9e \ue0 cette situation. L\u2019objectif de cette \ue9tude \ue9tait d\u2019\ue9valuer les qualit\ue9s agronomiques des pyramides g\ue9n\ue9tiques avanc\ue9es d\ue9velopp\ue9es d\u2019un croisement de quatre parents pour la r\ue9sistance aux maladies multiples. Les g\ue8nes pyramid\ue9s de r\ue9sistance (R) \ue0 la maladie de quatre parents \ue9taient\ua0: Co42 et Co-5 de G2333; Phg-2 de MEX54; Pythium ultimum Dennis de MLB49-89A et I & bc3 de MCM5001. Les lign\ue9es de prog\ue9nitures \ue9taient plant\ue9es en arrangement de block incomplet et r\ue9pliqu\ue9 trois fois pendant deux saisons (2015A et 2015B) dans les champs \ue0 CIAT, Kawanda en Ouganda. Les traits agronomiques \ue9taient hautement h\ue9ritables (0,6), \ue0 l\u2019exception du nombre de gousses par plant (<0.3). Le r\ue9trocroisement a g\ue9n\ue9r\ue9 des lign\ue9es d\u2019haricot \ue0 haut rendement, avec 270-290 graines par plant et \ue0 maturit\ue9 pr\ue9coce (95-100 jours). Neuf lign\ue9es sup\ue9rieures avec des qualit\ue9s d\ue9sirables, telles que la pr\ue9cocit\ue9 (95 jours), taux de graines \ue9lev\ue9s (290 graines par plant) et l\u2019habilit\ue9 grimpante, \ue9taient obtenues. La pyramide des g\ue8nes R n\u2019avait pas affect\ue9 les traits li\ue9s au rendement, \ue0 l\u2019exception de la p\ue9riode de floraison et le nombre de bougeons de fleurs par plant d\ufb \ue0 la s\ue9gr\ue9gation transgressive

Legume breeding and seed systems for improved livelihoods and impact

The Tropical Legumes III project aims to reduce food insecurity in drought-prone areas of Sub Saharan Africa (SSA) and South Asia (SA), through improved productivity and production of four major grain legumes – chickpea, common bean, cowpea and groundnut. This is being sone by conducting research under three complementary research and delivery pillars: support for the development and release of farmer-preferred varieties; strengthening of the legume breeding capacity of partner CGIAR centers (ICRISAT, IITA and CIAT), and national partners Burkina Faso, Ghana, Mali, Nigeria, Ethiopia, Tanzania and Uganda; and establishment of sustainable seed delivery systems that service the needs of small-holderfarmers. Significant achievements have been recorded. Breeding program assessments have been completed in all countries and improvement plans developed for execution. New seed varieties (163) have been released and are fast replacing the old ruling seed varieties in all target countries. Thirty seven national partners were trained at MSc and PhD levels. As a result of the enhanced skills and knowledge of seed value chain actors, seed production significantly increased by 221% (from 139,048 to 446,359 tons) in seven years. Since 2007, improved varieties have been adopted on at least 2 million hectares and more than $448 million has been generated from the project funding and nearly$976 million from the project and investment partners. For each dollar invested, the project generated $9 with direct project investment or$20 with partnership’s investment, and again $20 when using adoption rate based estimate. These achievements and implementation challenges will be discussed

Analysis of the Yellow Bean Corridor in Tanzania

The yellow bean value chain in Tanzania was necessary to understand value chain. The objective of the survey was to characterize and explore trade of yellow bean grain and potential seed. The survey collected data and grain samples from 298 grain traders (including wholesalers, exporters, aggregators, and retailers) and 64 potential seed traders (large and retail traders) from 12 regions across four administrative zones in Tanzania. The grain samples collected were for DNA analyses. Results show existence of an established yellow bean corridor across Tanzania and the region at large (Burundi, DRC, Kenya, Rwanda, Uganda, Zambia) and demonstrated a huge market pull in the Eastern and Southern Africa regions. There are also strong perceptions on the organoleptic quality of various yellow bean grains and varieties that are traced to their sources

Genetic patterns of common-bean seed acquisition and early-stage adoption among farmer groups in western Uganda

Widespread adoption of new varieties can be valuable, especially where improved agricultural production technologies are hard to access. However, as farmers adopt new varieties, in situ population structure and genetic diversity of their seed holdings can change drastically. Consequences of adoption are still poorly understood due to a lack of crop genetic diversity assessments and detailed surveys of farmers’ seed management practices. Common bean (Phaseolus vulgaris) is an excellent model for these types of studies, as it has a long history of cultivation among smallholder farmers, exhibits eco-geographic patterns of diversity (e.g., Andean vs. Mesoamerican gene-pools), and has been subjected to post-Columbian dispersal and recent introduction of improved cultivars. The Hoima district of western Uganda additionally provides an excellent social setting for evaluating consequences of adoption because access to improved varieties has varied across farmer groups in this production region. This study establishes a baseline understanding of the common bean diversity found among household producers in Uganda and compares the crop population structure, diversity and consequences of adoption of household producers with different adoption practices. Molecular diversity analysis, based on 4,955 single nucleotide polymorphism (SNP) markers, evaluated a total of 1,156 seed samples that included 196 household samples collected from household producers in the Hoima district, 19 breeder-selected varieties used in participatory breeding activities that had taken place prior to the study in the region, and a global bean germplasm collection. Households that had participated in regional participatory breeding efforts were more likely to adopt new varieties and, consequently, diversify their seed stocks than those that had not participated. Of the three farmer groups that participated in breeding efforts, households from the farmer group with the longest history of bean production were more likely to conserve “Seed Engufu”, a local “Calima”-type variety of the Andean bean gene pool, and, at the same time, introduce rare Mesoamerican gene pool varieties into household seed stocks

Genetic Patterns of Common-Bean Seed Acquisition and Early-Stage Adoption Among Farmer Groups in Western Uganda.

Widespread adoption of new varieties can be valuable, especially where improved agricultural production technologies are hard to access. However, as farmers adopt new varieties, in situ population structure and genetic diversity of their seed holdings can change drastically. Consequences of adoption are still poorly understood due to a lack of crop genetic diversity assessments and detailed surveys of farmers' seed management practices. Common bean (Phaseolus vulgaris) is an excellent model for these types of studies, as it has a long history of cultivation among smallholder farmers, exhibits eco-geographic patterns of diversity (e.g., Andean vs. Mesoamerican gene-pools), and has been subjected to post-Columbian dispersal and recent introduction of improved cultivars. The Hoima district of western Uganda additionally provides an excellent social setting for evaluating consequences of adoption because access to improved varieties has varied across farmer groups in this production region. This study establishes a baseline understanding of the common bean diversity found among household producers in Uganda and compares the crop population structure, diversity and consequences of adoption of household producers with different adoption practices. Molecular diversity analysis, based on 4,955 single nucleotide polymorphism (SNP) markers, evaluated a total of 1,156 seed samples that included 196 household samples collected from household producers in the Hoima district, 19 breeder-selected varieties used in participatory breeding activities that had taken place prior to the study in the region, and a global bean germplasm collection. Households that had participated in regional participatory breeding efforts were more likely to adopt new varieties and, consequently, diversify their seed stocks than those that had not participated. Of the three farmer groups that participated in breeding efforts, households from the farmer group with the longest history of bean production were more likely to conserve "Seed Engufu", a local "Calima"-type variety of the Andean bean gene pool, and, at the same time, introduce rare Mesoamerican gene pool varieties into household seed stocks