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

[Goals] [Outputs]

Goals

• Lasting increase in food availability and income for poor small farmers (mainly women) through improved bean productivity, especially in tropical America and eastern, central, and southern Africa. Poor consumers, especially women and children, benefit from low-cost protein and micronutrients.
• Poor farmers have enhanced access and use of improved cultivars and management practices.
• The environment and community at large benefit from reduced pesticide and fertilizer use.
• NARS, other partners, and providers of research and extension services collaborate and commit resources to innovative approaches to reach end users.
• Food-legume researchers access an enhanced knowledge base and a wider range of germplasm through participation in regional networks.
  

Outputs

• Improved, Small-Seeded, Bean Germplasm Resistant to Major Biotic and Abiotic Stresses with Greater Nutritional and Market Value
• Improved, Large-Seeded, Bean Germplasm Resistant to Major Biotic and Abiotic Stresses with Greater Nutritional and Market Value
• Strategies Developed for Managing Diseases and Pests in Bean-Based Cropping Systems
• Approaches and Methods Developed and Available for Strengthening Institutional, Organizational, and Collaborative Capacity of NARS and Subregional Networks in Africa and Latin America
  
  

Output 1: Improved, Small-Seeded, Bean Germplasm Resistant to Major Biotic and Abiotic Stresses with Greater Nutritional and Market Value

Developing Germplasm Tolerant of Abiotic Stresses: Drought and Low Soil Fertility

• A physiological evaluation of advanced lines at Palmira resulted in the identification of three lines (SER 16, SER 5, and SEA 5) that showed improved adaptation to drought. Their superior performance was associated with higher values for pod harvest index and leaf area index, a lower proportion of pod-wall biomass, and a lower value for seed P content. This last indicated the importance of greater mobilization of photosynthates to pods and seeds per unit of seed P under rainfed conditions. The SER lines that were developed over the last few years seem to combine the desirable traits for drought adaptation.
• Lines selected for drought yielded at least as well as, and sometimes significantly more than, commercial checks, indicating that selection for drought does not reduce yield potential. Rather, daily yield increased in many materials, suggesting that plant efficiency in grain production was increased. This efficiency was also observed under the stress of low availability of soil phosphorus. Some drought-resistance traits appear to also contribute to yield under nondrought conditions.
• A physiological evaluation of 33 recombinant inbred lines (RILs) of the cross DOR364 x BAT 477 at Palmira resulted in the identification of two lines (BT21138-17-1 1 and BT21138-36-1-1) that showed improved adaptation to drought. Their superior performance was associated with higher values for the pod harvest index and shoot N uptake, a lower proportion of pod-wall biomass, and a lower value for seed P content. This last indicated the importance of greater mobilization of photosynthates to pods and seeds per unit of seed P under rainfed conditions.
• A greenhouse evaluation of 15 advanced lines and one accession of common bean, using the soil-sampling tube method for root phenotyping, led to the identification of three lines (SEA 5, BAT 477, and SER 16) that had superior root development under drought.
• A greenhouse evaluation of 30 RILs of the cross DOR364 x BAT 477, two parents, and six checks of common bean, using the soil-sampling tube method for root phenotyping, resulted in the identification of two RILs (BT21138-124-1-4 and BT21138-6-1-1) with greater ability for fine-root development at deeper soil depths than the other RILs evaluated.
• Lines derived from intergene pool crosses and selected under the stress of Al toxicity yielded better than the check VAX 1, suggesting that different mechanisms from both gene pools had been combined.
• A screening procedure was modified to evaluate genotypic variation in Al resistance in common bean. Three Andean genotypes (G 5273, ICA Quimbaya, and G 19833) and one Mesoamerican genotype (G 21212) were found to be relatively resistant to Al, according to % inhibition of primary root elongation and total root length per plant.
• More than 530 bean genotypes from the two gene pools and segregating populations were screened for Al and Mn toxicity, soil acidity, and salinity in primary and secondary sites in seven countries.
• We selected 65 lines of diverse grain types for tolerance of Al and Mn toxicity and the acid-soil complex.
• New tolerant lines showed more than 47% yield advantage over checks under stress conditions.
• We identified 12 lines tolerant of saline soils.
• We validated 52 lines with farmers in five countries.
• Ten varieties tolerant of the low soil pH complex were released.
• Lines were developed from crosses combining parents for drought resistance and low-P tolerance. Yield trials indicated that, under moderate P stress, some of these have a large advantage over standard checks for low soil fertility. Some of these lines were derived from intergene pool crosses, employing Andean climbing beans as sources of low-P tolerance.
• A physiological evaluation of 30 RILs of the cross DOR364 BAT 477, two parents, and four checks under low-P stress showed that one line (BT211138-98-1-1-M-M-M-M M) was similar to BAT 477 in its adaptation to low P but more responsive to high-P supply because it had greater ability to acquire P. The use of non-nodulating lines provided field evidence for the role of nodulation in improving low-P adaptation and P responsiveness.
• A physiological evaluation of 14 advanced lines and two checks under low-P stress showed that two lines (NCB 226 and SER 118) were outstanding in their adaptation to low-P stress. This was attributed to their greater ability to mobilize photosynthates from pod walls to seeds.
• More than 1143 bean lines of diverse grain types and gene pools were screened for tolerance of low soil P in primary and secondary sites in eastern Africa.
• More than 51 lines tolerant of low soil P were validated with farmers in Uganda, Tanzania, Kenya, Madagascar, DR Congo, and Rwanda.
• Five low-P tolerant bean varieties were released in eastern Africa.
• A strategy for developing bean lines tolerant of low soil N and other edaphic stresses developed and implemented in several countries in eastern and central Africa.
• More than 1337 bean genotypes were screened for tolerance of low soil N on-station and with farmers.
• More than 60 bean lines tolerant of low soil N and with diverse grain types confirmed in participatory trials in Uganda, DR Congo, Madagascar, Kenya, Tanzania, Ethiopia, Malawi, and Cameroon.
• Ten bean lines tolerant of low soil N and the acid-soil complex were released in six countries.
• More than 1337 bean genotypes from a broad genetic base were screened for multiple tolerance of low soil N, P, and K; Al and Mn toxicity; and the acid-soil complex in eastern Africa.
• At least 42 lines of diverse grain types showed multiple resistance to two or more edaphic stress factors.

Developing Germplasm with Multiple Resistance to Diseases

• Resistance to bean leaf crumple virus (BLCrV) was obtained in families with pod type approaching that of the commercial Blue Lake. This resistance was not associated with either the bgm-1 gene or the W12 QTL for resistance to BGYMV. Probably the Bgp-1 gene is contributing to the resistance.
• Several breeding lines were identified that combined high levels of resistance to the ALS pathogen, including the most virulent pathotype (63:63).
• We identified several interspecific lines that combine resistance to ALS, anthracnose, Ascochyta blight, and Rhizoctonia root rots. These materials constitute an important set for use in breeding programs intended for multiple constraint improvement.

Developing Germplasm with Resistance to Insect Pests

• Resistance to the bean weevil (Acanthoscelides obtectus) was identified in Phaseolus vulgaris x P. acutifolius hybrids.
• Progress was made with yields of lines selected for tolerance of the Empoasca kraemeri leafhopper.
• New accessions and lines with insect resistance were identified.

Developing More Nutritious Small-Seeded Bean Varieties

• Breeding lines with as much as 50%-60% more iron (Fe) than commercial checks have been recovered. The highest levels were found in Brazilian grain types.
• The Nicaraguan national program has selected locally adapted lines out of CIAT's populations. The criteria were accepted red color, drought tolerance, resistance to BGYMV, and 30%-40% higher Fe.
• The use of near-infrared spectrophotometry (NIRS) to estimate Fe concentration in bean is being implemented.
• A rapid method for estimating the cooking time of dried beans was developed, using a penetrometer that is used in soil physics to measure soil compaction. Most lines in the breeding program cooked in either a short or very short time.
• An application of P at 25 kg ha^-1 significantly increased grain yield. Higher P levels depressed grain yield.
• An application of P at 50 kg ha^-1 increased seed Fe concentration in 10 bean genotypes, but higher levels depressed Fe concentration.
• Zinc (Zn) concentration in seed was increased by fertilizer applications of P at 50 kg ha^-1.
• Line AND 620 and cv. Maharagi Soja had the highest seed Fe concentrations across sites and seasons.
• Line VNB 81010 had the highest Zn concentrations in all trial sites and seasons.
• Environmental factors were found to influence seed mineral concentration.
• Fertilizer applications of N at 100 kg ha^-1 increased bean yields at all trial sites over two seasons.
• Applications of N at 100 kg ha^-1 significantly increased seed Fe concentration across sites and seasons, with the mean concentration varying from 71.4 ppm for landrace Nakaja to 91.7 ppm for AND 620.
• Fertilizer applications of N at 100 kg ha^-1 significantly (P < 0.05) increased seed Zn concentration, which varied from 26.1 ppm for landrace Nakaja to 35.6 ppm for MLB-49-89A and 36.7 ppm for VNB 81010.
• Significant genotype x environment interactions were detected for seed mineral concentration.
• Applications of K at 100 kg ha^-1 increased grain yield across sites and seasons.
• Fertilizer applications of K at 150 kg ha^-1 increased seed Fe concentration in sites with low native K.
• Fertilizer applications of K increased seed Zn concentration, but optimal rates varied with site and season.
• Seed Fe concentration varied from 59.9 ppm for M211 to 98.1 ppm for AND 620.
• Line VNB 81010 (39 ppm) had the highest seed Zn concentration.
  

Output 2: Improved, Large-Seeded, Bean Germplasm Resistant to Major Biotic and Abiotic Stresses with Greater Nutritional and Market Value

Developing Germplasm Resistant to Diseases

• We developed 164 advanced climbing-bean lines (white and yellow-seeded; BCMV-resistant) through marker-assisted selection. They were yield tested for the first time to create nurseries of improved genotypes in these neglected seed classes.
• The PYAA19₈₀₀ SCAR marker associated with the Pythium root-rot resistance gene in RWR 719 was validated and successfully used in selection for resistance.
• The SW13 and ROC markers for "I" and bc-3 genes, respectively, which condition resistance to BCMV, were successfully used to improve resistance to BCMV and BCMNV.
• Marker-assisted selection was applied to breeding Andean red-seeded climbing beans for field-based selection of 188 advanced lines and 282 gamete-derived families as part of a collaborative project with the Universidad Nacional de Colombia to improve bola roja type beans.
• Progenies (populations and lines) showing multiple resistances to ALS, BCMV, and Pythium root rot were identified and some were distributed to partners.
• A good level of resistance against Fusarium root rot was identified and conditions influencing its expression determined. This information is being used to genetically improve large-seeded commercial varieties.
• In participatory selection with farmers, we identified 22 mid-altitude climbing-bean lines (red mottled, red kidney, yellow, and purple) from segregating populations. The lines had marketable grain types and high yield potential.
• Three new climbing-bean lines showed outstanding performance in multi-site trials.
• First formal release of improved climbing-bean varieties in Kenya.
• We selected 37 segregating populations for multiple-disease resistance for eight generations.
• Resistance to BCMV in L226-10 is conditioned by a single dominant gene.
• Resistance to halo blight in a Kenyan landrace (NB 123) is governed by more than three dominant genes.
• Resistance to anthracnose in NB 123 is controlled by a single dominant gene.
• Resistance to rust in NB 123 and L226-10 is controlled by two dominant non-allelic genes.
• Three new sugar bean varieties of growth habits 1 and 4 were released for commercial production in Kenya. Their yield stability, multiple-disease resistance, and yield advantage were as much as 17.7% superior to those of the best check.
• Five new red-mottled varieties were released for commercial production.
• Cultivar E8 was the best yielding line in multi-site trials. It showed less incidence and/or severity of symptoms for ALS, anthracnose, BCMV, halo blight, and common bacterial blight (CBB) than did commercial checks.
• New red-mottled releases showed a yield advantage of up to 29% over the best check and up to 37% over the mean of the checks. They also showed multiple-disease resistance and high yield stability.
• Three new red-kidney bean lines with multiple-disease resistance were released for commercial production.
• New red-kidney cultivars showed a yield advantage of 10.5% over the best check and 17.8% over the mean of the checks, plus multiple-disease resistance.
• A few bean lines were selected from Malawi in the cream mottled (sugar), brown/tan (khaki), red mottled (calima), and small white (navy) market-class nurseries. These combined two or more attributes such as high yield and resistance to at least two diseases. Their seed was increased under irrigation (June-September 2006) for distribution to NARI partners within the SABRN.
• In South Africa, we selected 29 lines with enhanced levels of CBB resistance and 51 lines combining ALS and rust resistance, all with accepted seed types across different countries. They were sent to the SABRN coordinator to distribute to other countries for further evaluation.
• The use of markers linked to the Ur-5 gene for rust resistance was optimized. This method was discovered to differentiate the related canning bean varieties Teebus and Teebus RR-1 at the DNA level. An extra unique band amplified in the latter variety.

Developing Germplasm Resistant to Insects

Andean beans, from a backcrossing program to introduce the arcelin gene that confers resistance to Zabrotes spp., yielded comparably with the recurrent parent.

Incorporating Wider Genetic Diversity into Beans

Lines were developed in beans with bush Andean growth habits and with commercial grain types that significantly outyielded the drought-resistant check ICA Quimbaya.

Developing More Nutritious Large-Seeded Bean Varieties

• We evaluated 984 genotypes from Rwanda for seed Fe and Zn concentrations and found up to 115 ppm Fe and 49 ppm Zn in genotypes with the highest mineral contents.
• We evaluated a national collection of 248 Phaseolus genotypes from Bolivia to determine seed Fe and Zn concentrations, and found that average concentrations were higher for wild than for cultivated accessions. The highest Fe concentrations were found in P. lunatus, with values for cultivated common bean (P. vulgaris) at 100 ppm. For Zn, the highest values were for P. coccineus, with P. vulgaris at 51 ppm. This work was done in close collaboration with the Centro de Investigaciones Fitoecogenéticas de Pairumani (Cochabamba), which conserves the country's national collection of common Phaseolus beans.
• The micronutrient breeding program for Andean beans generated 169 climbing-bean and 103 bush-bean genetic combinations, using simple, triple double, or multiple crosses. Parents were three high-Fe landraces, BCMV-resistant climbing beans from the MBC series, ALS-resistance sources, and varieties from the Andean Region and eastern and southern Africa.
• A fertilizer application experiment was conducted, using 40 Colombian varieties to measure the effect of P fertilizer levels on seed Fe and Zn contents.
• A multi-site trial was conducted for the advanced NUA (Andean nutrition) breeding lines at multiple sites in Latin America, including two sites in Bolivia (71 lines) and one site in Colombia (100 lines). The highest-Fe breeding lines had 99 and 109 ppm in Colombia and Bolivia, respectively.
• Condensed tannins were evaluated in 17 genotypes from the DOR364 x G 19833 population to determine the association of tannins with seed color, using HPLC analysis. This builds on our work with the butanol-HCl assay of soluble and insoluble condensed tannins from last year but increases our potential to evaluate tannin subcomponents such as anthocyanin derivatives, cyanidin, delphinidin, and pelargonidin.
• Phytic acid was measured in collaboration with the Michigan State University, using HPLC analysis for the first time, for the RIL population of AND 696 x G 19833.
• Seed of high-Fe NUA (Andean nutrition) breeding lines was increased for a bioefficacy trial with UNIVALLE in the FONTAGRO project, Cali, Colombia. The same seed has been and will be tested for bioavailability parameters. We continued conducting on-farm trials in the Colombian Departments of Valle, Cauca, and Nariño, as well as in eastern and southern Africa.
  

Output 3: Strategies Developed for Managing Diseases and Pests in Bean-Based Cropping Systems

Characterizing and Monitoring Pathogen and Insect Diversity

• The anthracnose population structure in Colombia has changed, with some previously prevalent pathotypes having disappeared. However, the population remains exclusively from the Andean lineage.
• Preliminary analysis of cDNA from compatible and incompatible interaction events identified transcripts with homology to genes known to be involved in resistance (Prf and Co-4 anthracnose-resistance genes) and pathogenicity.
• Several Pythium species found on crops grown in association with beans were pathogenic to beans, sorghum, and peas, particularly the last two.

Characterizing Genes for Resistance to Diseases and Insects

• Molecular markers that are linked to Pythium root-rot resistance in RWR 719, MLB-49-89A, and AND 1062 were identified, and protocols for two SCARs (PYAA19₈₀₀ and PYB08) were developed. These markers are currently being used in MAS for root rots in Kampala, Uganda.
• Analysis of allelic relationships between different sources of ALS resistance revealed the complex nature of this resistance in common bean. More information will be gained when these studies are completed and the markers linked to ALS resistance genes mapped.
• The PF9₂₆₀ SCAR marker linked to resistance genes in G 10474 and G 10909 functions effectively in both Andean and Mesoamerican backgrounds.

Developing Components of Integrated Disease and Pest Management

• Significant changes in whitefly species composition were detected in the targeted area.
• The efficiency of pesticides that may help control whiteflies in the targeted region was evaluated.
• Continued and expanded the diffusion of technology activities within the DFID-funded project on "Sustainable Management of Whiteflies".
• Losses to a new virus (bean leaf crumple virus) on snap beans were measured.
• Successful screening for sources of resistance to the new virus disease affecting snap beans was conducted.
• Several social, economic, and environmental factors influence local bean diversity in southwestern Uganda. Indigenous knowledge was collected on bean diversity management and will help in designing options for root-rot disease management.
  
  

Output 4: Approaches and Methods Developed and Available for Strengthening Institutional, Organizational, and Collaborative Capacity of NARS and Subregional Networks in Africa and Latin America

Strengthening the Capacity of NARS: Increasing the Knowledge and Skills of Scientists and Staff from NARIs, NGOs, and Rural Service Providers

• In Latin America, one PhD candidate received his degree; and three MSc candidates and two undergraduate students completed their research theses, of which two were judged as meritorious. In Africa, two PhD and seven MSc candidates completed their research theses. One received an academic award for the highest marks among MSc candidates in crop sciences from the University of Nottingham, UK.
• We continue supervising 42 students, as follows: 11 PhD candidates (3 in Africa and 8 in Latin America), 20 MSc candidates (11 in Africa and 9 in Latin America), and 11 undergraduates (1 in Africa and 10 in Latin America).
• Another student received support from the SABRN to enroll at the University of Lubumbashi, DR Congo, as part of the Network's initiative to build research capacity of NARS partners in the region.
• Training in different disciplines was given at headquarters to 13 visiting researchers from Bolivia, Canada, Colombia, Mozambique, Nicaragua, and USA.
• Several courses and workshops were held in Latin America and Africa.

Strengthening International Collaboration through Networks (Intra- and Internetwork Collaboration), Bilateral Relationships, and/or Joint Special Projects

• The Pan-African Bean Research Alliance (PABRA) continued to fund research to develop subprojects within the SABRN.
• Concept notes or full proposals for 10 new projects were prepared.

Supporting Breeding Programs in NARS, Regional Networks, Farmers' Associations, and CIALs with Germplasm and Technical Knowledge

• More of our fixed lines, cultivars, and released bean varieties were distributed to selected countries through a regional yield trial to various NARI partners. These materials combined accepted market classes, high-yield potential, and resistance to diseases.
• This year, the national bean research programs of southern DR Congo, Mozambique, and Swaziland released eight bean varieties. These were XAN76, DOR715, and DB196 in DR Congo; Jenny, Teebus RR-1, and CAL 143 in Swaziland; and CAL 143 and SUG 131 in Mozambique. Some of these varieties combined accepted market classes with high-yield potential, resistance to various diseases, and tolerance of low soil fertility conditions.

Developing Sustainable Seed Systems to Support Wide Dissemination

We reached an estimated 1 million farming households across 15 countries.

Socioeconomic Activities

• Participatory monitoring and evaluation (PM&E) was introduced into four national bean programs in southern Tanzania, Mozambique, Malawi, and western Kenya. At the same time, we continued to strengthen seven additional national bean programs in northern Tanzania, southern and eastern DR Congo, Ethiopia, Zambia, Madagascar, and Uganda.
• We synthesized data acquired through PM&E to help track progress made in member countries of the Pan-African Bean Research Alliance (PABRA) against regionally developed milestones in the Alliance's performance framework.
• We facilitated PABRA's decision-making process; catalyzed opportunities for feedback and learning; and defined key focus areas for the short, medium, and long term. These activities were useful in mapping the road for PABRA's implementation plan for phase two.