For further information contact: ciat-bean@cgiar.org

Products

• Beans with improved micronutrient concentrations and that have a positive impact on human health
• Beans that are more productive in smallholder systems of poor farmers
• Beans that respond to market opportunities
• Strengthened institutions that enhance bean product development and delivery

Product 1: Beans with improved micronutrient concentrations and that have a positive impact on human health

Developing more nutritious bean varieties

• More than 30, F_3-5, small-seeded, Mesoamerican families were selected for high mineral concentrations and some degree of drought resistance.
• Eighteen lines, derived from interspecific crosses, were coded as MIB (high mineral) lines. They had higher iron (Fe) levels than the high-iron check MIB 465. Some also had superior resistance to foliar pathogens.
• In SABRN countries, more than 200 hand pollinations were generated. These combined multiple sources of resistance to diseases and drought with high mineral (Fe and Zn) contents.
• Some suitable donor parents for drought resistance in common bean (SEA 5, SEA 15, and SER 16) were also suitable for high Fe and Zn contents.
• Several populations, combining different market classes with sources of resistance to diseases or drought and possessing high mineral (Fe and Zn) contents, have been generated. Micronutrient-dense bean varieties (4 bush and 3 climbing), with high yield potential were pre-released for small farmer production in eastern Africa. This was the first time biofortified, mineral-dense, bean varieties were formally recommended for release, following independent evaluations.
• Bioavailability of Fe in raw samples of fast-track lines varied from 1.1% to 6.6%.
• Bioavailability of Zn in raw samples of fast-track lines varied from 0.5% to 2.5%.
• Cooking enhanced Fe and Zn bioavailability in beans by more than twofold.
• Freshly shelled beans have more bioavailable Fe and Zn than dry beans.

Genotype environment interaction

• NUA35 and NUA56 were tested for yield potential and mineral accumulation across 15 sites in Latin America (72 replicates). Both lines were shown to have higher Fe concentrations than CAL 96, by 15 to 25 ppm more.
• Significant genotype environment interactions indicate that mineral concentrations in grain are influenced by soil type, soil nutrient status, moisture concentration, and other environmental factors, with the magnitude varying according to genotype. Some genotypes were highly stable for mineral density.
• Fertilization regimes and other agronomic practices may enhance the expression of high mineral-density traits.

Associated traits: anti-nutrients

• The inheritance of seed phytate content was analyzed to determine (1) if this group of anti-nutrients could be reduced, and (2) how it relates with seed-phosphorus (P) content. Quantitative inheritance was found, with several QTLs explaining both traits, independently of seed size. The results of this study identified genotypes with phytate levels that are, apparently, sufficiently low for breeding purposes.
• Condensed tannins, another group of anti-nutrients, are also being analyzed. An HPLC method was adapted to examine the tannin monomers that accumulate in genotypes from an inter-gene pool population.

Product 2: Beans that are more productive in smallholder systems of poor farmers

Developing germplasm tolerant of abiotic stresses-drought resistance

• Mesoamerican crosses among drought-resistant parents that also express tolerance of low soil-P availability produced more than 20 lines with high drought resistance. Some lines later showed adaptation to low P in Darién (Colombia), producing grain of excellent quality under combined drought and low-P stress.
• Another 15 Mesoamerican families combined drought tolerance and the bc-3 gene for resistance to BCMNV.
• To incorporate drought tolerance in Andean bush beans, we created a series of 216 advanced drought-tolerant Andean bean (DAB) lines from inter- and intra-gene pool crosses. The crosses involved five commercial genotypes from southern Africa and 10 sources of drought tolerance. Half of these were Andean and the other half were Mesoamerican, producing 46 populations. The lines represented large red, red-mottled, and cream-mottled seed types. Selection focused on bush-bean architecture, adaptation to drought stress, and yield potential under favorable conditions, using alternate dry- and rainy-season plantings.
• A reference collection of landraces from the CIAT core collection was evaluated in the field for drought tolerance and compared with a series of check genotypes. The reference collection was stratified into Andean and Mesoamerican gene pools and the association of drought tolerance with subgroups and common bean races was analyzed.
• A series of SAB (drought-resistant Andean) lines was tested in Darién (Colombia) for mid-altitude adaptation. These lines were originally developed from crosses between drought-resistant genotypes (SAB 258, SAB 259, and ICA Quimbaya) and drought-susceptible but commercial genotypes (ABA36, ABA58, and COS 16). Results confirmed that the SAB lines expressed superior drought tolerance and yield potential over their tolerant and susceptible parents. The same lines were also tested under rainfed conditions in Palmira. Several maintained their yield advantage over local checks. Based on this analysis, certain SAB lines with greater stability across mid-altitude and lower-altitude sites can be selected.
• Field evaluation of elite lines at Palmira resulted in the identification of five lines—NCB 226, SEN 56, SER 113, SER 125, and SER 16—that were outstanding in their adaptation to drought. The superior performance of these lines was associated with higher values for harvest index, pod-harvest index, leaf area index, and canopy biomass. The SER lines developed in recent years seem to combine desirable traits for drought adaptation, such as greater mobilization of photosynthates to seed with efficient water use through stomatal control.
• Field evaluation of 33 RILs of the cross DOR364 BAT 477 at Palmira over two seasons under terminal-drought conditions resulted in the identification of two lines (BT21138-17-1-1 and BT21138-6-1-1) with improved adaptation. Their superior performance was associated with higher values for harvest index, pod-harvest index, and seed and pod number per area, indicating the importance of greater photosynthate mobilization to pods and seeds under rainfed conditions.
• Field evaluation of 97 RILs of the cross DOR364 BAT 477 under intermittent-drought conditions resulted in the identification of two RILs (BT21138-68-1-1 and BT21138-74-1-1) that were outstanding in adapting to intermittent-drought conditions. Their superior performance was associated with higher values for harvest index, pod-partitioning index, stem biomass reduction, and seed and pod number per area, indicating the importance of greater photosynthate mobilization to pods and seeds under rainfed conditions.
• Field evaluation of 121 RILs of the cross MD 23-24 SEA 5 over three seasons resulted in the identification of lines MR 81 and MR 25, which showed improved adaptation to drought stress. Their superior performance was associated with higher vigor; and higher values for pod-harvest index, harvest index, and seed number per area, highlighting the importance of photosynthate mobilization to pods and seeds under intermittent-drought conditions.
• Seven common bean genotypes were tested for their response to inoculation with Rhizobium etli strain CIAT 632 under drought conditions. Pinto Villa adapted best to drought because it decreased stomatal conductance, whereas Alubia Cerrillos was the most affected. Although none of the genotypes responded to inoculation, the effect of terminal drought on nodulation was very marked in all.

Developing germplasm tolerant of abiotic stresses-resistance to aluminum toxicity

• Lines derived from an interspecific cross of SER 16 (drought-resistant line) with Phaseolus coccineus (G 35346) yielded well under both rainfed and aluminum (Al) toxic conditions. Indeed, some yielded more than SER 16 under intermittent drought.
• SER 16 proved to be a highly suitable common-bean parent to cross with P. coccineus, perhaps because of its trait of excellent remobilization to grain.
• A filter paper-Styrofoam® sandwich germination method was developed to improve the capacity to phenotype for Al resistance in common bean. A primary-root marking method was also developed to evaluate short-term effects of Al on root elongation.
• A method for screening for Al resistance in common bean was adapted and validated, based on the qualitative determination of Al-complexing compounds, including citrate released from roots.
• Phenotypic evaluation of 20 common bean genotypes for Al resistance confirmed three Andean genotypes (ICA Quimbaya, BRB198, and G 5273) and one Mesoamerican (G 24601) as having higher levels of Al resistance.
• Phenotypic evaluation of 97 RILs of the cross DOR364 BAT 477 for Al resistance resulted in the identification of some RILs with low inhibition for root growth under high Al in solution. Two RILs (BT21138-128-1-M-M-M and BT21138-2-1-1-M-M-M) were outstanding for root growth, both with and without Al in solution.

Developing germplasm with resistance to insect pests (bruchids and leafhopper)

• New accessions from the gene bank were evaluated for insect resistance.
• Resistance to the Mexican bean weevil Zabrotes subfasciatus was reconfirmed.
• New breeding lines were identified as having resistance to the leafhopper (Empoasca kraemeri).
• Some Andean bean lines presented high levels of tolerance of Empoasca, together with less yield loss.

Developing disease-resistant germplasm

• Numerous crosses were made to pyramid insect (bruchid) and disease (BCMNV and CBB) resistance with drought tolerance or mid-altitude adaptation in Andean bush beans. The arcelin gene was used as the source of bruchid resistance and was effectively selected in 115 different cross combinations. Meanwhile, 187 cross combinations were generated for disease resistance. These crosses are being advanced at drought-stress and mid-altitude sites in Colombia.
• Eighty-five new varieties were released in various countries of eastern and central Africa, as follows:

• Several segregating populations and fixed lines in different market classes from the Rep. of South Africa, Malawi, and Tanzania are now available for distribution to interested NARS partners in SABRN and others in Africa.
• From the regional breeding program, 24 brown/khaki, 73 sugar, and 213 red-mottled lines were distributed to various NARS programs. The lines had been developed for resistance to either angular leaf spot, or common bacterial blight, or low soil fertility, or a combination of these stresses.
• Twenty-nine lines in various market classes were sent to the SABRN coordinator for seed increase and onward distribution to other interested NARS for the next planting season. These lines had been developed by the NARS in southern Africa to possess rust resistance, or a combination of resistances to rust and angular leaf spot, or rust and halo blight.
• Twenty-four new lines, possessing a gene for resistance to Pythium root rot, were identified and included in the Pythium root-rot nursery.
• Forty lines, combining resistances to Pythium root rot and angular leaf spot, were identified and made available for sharing with partners.

Yield potential: climbing beans

• QTLs for growth habit and climbing ability were identified on six chromosomes, although many were located on linkage group B04. This illustrates the complexity of growth habit and, implicitly, of crop domestication, as growth habit was reduced from climbing to bush type.

Characterizing and monitoring pathogen and insect diversity

• Sixteen Pythium species were found to be associated with bean root rots in Rwanda. The cultivars CAL 96, RWR 617-97A, Urugezi, and RWR 1668 were susceptible to all the Pythium species. In contrast, G 2331, AND 1062, MLB-40-89A, Vuninkingi, AND 1064, and RWR 719 were resistant.

Developing integrated disease-and-pest management components

• All the areas planted to beans in Colombia and Ecuador and included in the project financed by FONTAGRO (Reduction in the Use of Pesticides and Development of Resistance in Rice and Common Bean Crops in Colombia, Venezuela, and Ecuador) were monitored for whitefly populations.
• Whitefly species and biotypes, thrips, and leafminers were identified; patterns of pesticide use for whitefly, thrips, and leafminers recorded; and levels of pesticide resistance in whitefly, thrips, and leafminer populations in Colombia quantified.
• Pseudomonas spp. were isolated and shown to have antagonistic effects on Pythium spp.
• The genetic diversity of varietal mixtures from southwestern Uganda was characterized, and the potential value to the region indicated.
  

Product 3: Beans that respond to market opportunities

Developing large whites for international markets

• Crosses have been developed to combine alubia grain type (uniform, milky white, long, and cylindrical seeds) with drought resistance.

Breeding navy and large white varieties with multiple-stress resistance for eastern Africa

• Fourteen new varieties were released for small farmer production in four countries of eastern Africa. These varieties were navies or large whites, and combined resistance to multiple diseases and abiotic stress factors with high yield potential and marketable grain characteristics.

In Nicaragua, a varietal candidate with potential for international export is identified

• The INTA-Nicaragua bean program has selected for varietal release a line suitable for exporting grain to USA.

Progress in developing snap and runner bean varieties for small farmer production in eastern and central Africa

• Twenty bush or climbing snap-bean lines were selected for four countries of eastern Africa. The lines had consumer-preferred pod characteristics and disease resistance.
• Nineteen, new, runner-bean lines were selected for their high pod-yield potential. They were also adapted to short photoperiods, making small farmer production feasible in areas of eastern Africa with short-day conditions.
  

Product 4: Strengthened institutions that enhance bean product development and delivery

Strengthening capacity in NARS: increasing the knowledge and skills of scientists and staff from NARIs, NGOs, and Rural Service Providers

• A total of 49 students conducted research activities related to their thesis work, of which 28 were at CIAT headquarters (HQ) and 21 in Africa. Of the African students, three PhD and one MSc students were visiting scientists at HQ. Another 12 students completed their theses, including two MSc candidates and two undergraduates from Latin America, and three PhD, four MSc, and one BSc candidates in Africa. A further 33 continued their studies: six PhD candidates in Africa and five in Latin America, eight MSc candidates in Africa and four in Latin America, and 10 undergraduates in Latin America.
• Twelve visiting scientists received training in different disciplines at HQ. They came from Colombia, Cuba, Denmark, Guatemala, Hungary, India, Panama, and Zambia.
• Several courses and workshops were also held in Latin America and Africa.
• A joint stakeholders' meeting was held for PABRA partners, and a joint steering committee meeting for SABRN and ECABREN. The latter meeting reflected on the progress made over the past 4 years, and planned activities to achieve set milestones, thereby contributing towards the project's goals in its final year and planning for the next phase.
• Several students have either registered or started course work at various universities to sharpen their knowledge and skills in bean research for development. Two new students, both from Malawi and doing their MSc in plant breeding, enrolled at the University of Zambia and the Pennsylvania State University (USA). Two other students have been accepted for PhD programs at the University of the Free State (Rep. of South Africa) and Massey University (New Zealand). These scientists will add to the existing capacity for bean research in the region.

Strengthening international collaboration through networks (intra- and inter-network collaboration), bilateral relations, and/or joint special projects

• The Pan-Africa Bean Research Alliance (PABRA) continued to provide funding to support subprojects on research for development within the SABRN.

Providing germplasm and technical knowledge to support breeding programs in NARS, regional networks, farmers' associations, and CIALs

• More fixed lines with high yield potential and disease resistance, and cultivars of commercial value for the export market were distributed in a regional yield trial to various NARI partners in different countries.
• Early generation selections of interspecific crosses for high iron concentration have been carried out in ICTA (Guatemala), and are pending shipment to CIAT for analysis.
• Selections from EAP-Honduras have been analyzed and returned to the breeder there.
• High-iron lines are in validation trials in Nicaragua and a variety may be released during 2009.

Developing sustainable seed systems to support wide dissemination

• A strategy for marketing small seed packets as a profitable enterprise is being developed with a private seed company in Kenya. It promises to reach thousands of bean growers.
• An analysis of the effectiveness of training in seed production suggested that participants significantly improved both their technical and communication skills.
• A methodology for assessing seed security was accepted at the institutional level by significant players such as FAO, USAID, and international NGOs.

Socioeconomic activities

• A baseline study to determine the role of beans in drought-prone areas of eastern Kenya has been completed. Beans were found to be the second most important food after maize and to be critical for food security.