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

• Improved, small-seeded, bean germplasm resistant to major biotic and abiotic stress factors and combined with greater nutritional and market value
• Improved, Large-seeded, Bean Germplasm Resistant to Major Biotic and Abiotic Stresses and Combined with Greater Nutritional and Market Value
• Strategies developed for managing Diseases and Pests in Bean-based Cropping Systems
• Improved Cultivars and Management Practices developed and Tested in Partnership with our African Bean Project, NARS, and Regional Networks

Output 1: Improved, small-seeded, bean germplasm resistant to major biotic and abiotic stress factors and combined with greater nutritional and market value

Developing Germplasm with Tolerance of Two Abiotic Stresses: Drought and Low Soil Fertility

• Nearly 600 F₃-derived F₅ families were evaluated for drought, of which 138 were selected for drought tolerance in combination with commercial grain type and disease resistance.
• Two accessions of Phaseolus acutifolius (G 40068 and G 40159) and one bred line of P. vulgaris (RAB 650) were outstanding in their adaptation to water stress.   Their superior performance was associated with higher levels of nonstructural carbohydrates in shoot tissue at mid-podfilling stage and efficient use of acquired N and P for grain production.
• A common bean (P. vulgaris) landrace (G 21212) stood out for its adaptation to acid soils by showing increased ability to fill the grain, relative to unstressed conditions.
• A screening procedure, based on relative root elongation, was developed to evaluate genotypic variation in Al resistance in common bean.   The Andean genotype G 5273 was outstanding.
• Two bred lines (IPA 7 and MAM 38) and two germplasm accessions (G 1977 and G 21212) had superior tolerance of low P soil.  Of the four genotypes, G 21212 and IPA 7 were outstanding in their ability to use P and N for grain production.
• Evidence was found to support the hypothesis that flavonoids accumulate under abiotic stress conditions such as drought and low P soil.

Developing Germplasm with Multiple Resistance to Diseases

• A second marker (W12) for resistance to the bean golden yellow mosaic virus (BGYMV) was applied extensively with the marker for the bgm-1 gene to select advanced families for drought tolerance.
• Traditional breeding practices continue to produce common bean genotypes that are highly resistant to BGYMV, thereby reducing yield losses in Mesoamerica.
• Despite its low efficiency, the recessive gene (bc 3) for resistance to bean common mosaic virus (BCMV) is being incorporated into red-seeded common bean genotypes to maintain their commercial characteristics in Central America.
• Families obtained from exotic sources of resistance to angular leaf spot (ALS) expressed high levels of resistance in Santander de Quilichao, Colombia.
• Greenhouse evaluation of potential sources of resistance to ALS resulted in the identification of 21 interspecific lines that are highly resistant to race 63-63.  These lines are also highly resistant to anthracnose.
• Four advanced lines (MN 13338-38, MC 12832-129, MC 12832-129, and BM 12721-17), comprising small blacks, small reds, and cariocas, were resistant to race 63-63 of the ALS fungus Phaeoisariopsis griseola.
• When evaluating genotypes for their response to the charcoal rot fungus Macrophomina phaseolina, we discovered yield must also be considered.
• Two common bean genotypes (G 192 and DICTA 17) are tolerant of M. phaseolina, having quantitative resistance to this fungus.
• The participatory bean-breeding program encouraged:
  • Tanzanian farmers to select nine new lines with pest and disease tolerance: six of ALS and three of the bean stem maggot (BSM);
  • Farmers in eastern Ethiopia to select 18 new bean lines; and
  • Farmers in the Ethiopian Rift Valley Region to select two improved bean lines.
• Five, new, bean lines of small reds were selected for yields that were superior to those of popular commercial checks (with 8.6% to 33.9% advantage) and had resistance to root rots, rust, ALS, and anthracnose.
• Nine new carioca bean lines were selected for having a yield advantage of 19.2% over the commercial cultivar ‘Zebra’ and resistance and/or tolerance of major diseases.
• Fourteen new lines of navy beans were selected for their resistance and/or tolerance of rust, ALS, and root rots, and for their significantly higher grain yield over regionally popular cultivars.

Developing Germplasm Resistant to the Pests Zabrotes, Acanthoscelides, Empoasca, Apion, Thrips palmi, Leafhopper, Pod Weevil, and Bruchids

• New sources of resistance to E. kraemeri, Z. subfasciatus, and Ac. obtectus were identified.
• Progress was made in characterizing tolerance and antixenosis as mechanisms of resistance to Thrips palmi.
• Progress was made in developing molecular markers for resistance to Ap. godmani and Z. subfasciatus.
• Resistance to Ac. obtectus in P. vulgaris × P. acutifolius hybrids was identified.
• New lines incorporating insect resistance were developed.

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

Developing Germplasm Resistant to Diseases

• Popping beans (ñuñas) were crossed with resistance sources for anthracnose and BCMV to develop new bush-type and climbing varieties of ñuñas.
• Marker-assisted selection was applied to introgress resistance genes for BGYMV into advanced breeding lines of the red-mottled seed type.
• VAX lines were used to develop resistance to common bacterial blight (CBB) in beans of the red-mottled seed type.
• Resistance genes for BCMV and BGYMV were introgressed into mid-altitude, adapted, climbing (MAC) bean lines.
• Bush-type, cream-mottled, cargamanto beans were developed and tested for resistance to BCMV.
• Field evaluation of nearly fixed lines (F6) at two sites in Malawi —Chitedze (CBB and moderate soil fertility) and Bembeke (ALS and low soil fertility)—has shown that genotype RA 13018-3-1 was promising at both sites and for both ALS and CBB.
• Eight VTTT lines (four for ALS and four for low soil fertility), originally developed at CIAT headquarters, showed good levels of resistance to biotic and abiotic stresses.
• The breeding program for specific market classes, led by the South African national program, has produced five large-seeded lines, of which two show resistance to CBB and three to ALS.
• The South African program also identified 10 additional sources of resistance in medium- to large-seeded germplasm, four to ALS and six to CBB.
• A CIAT-Malawi bred line, CIM 9314-31, was consistently outstanding at both Chitedze and Bembeke, when it was evaluated under moderate and low soil fertility conditions (low N, P, and pH).
• Seventeen sets of the Southern Africa Regional Bean Yield Trial (SARBYT) were distributed to 10 SADC countries
• Eight other nurseries, organized according to either bean market grain type or production constraint, were distributed to various countries in the SADC region on request.
• Genotypes from the Peruvian highlands were shown to be tolerant of low soil P and highly resistant to several anthracnose races.
• Nearly half of 364 red-mottled and red-kidney lines showed resistant reactions to P. griseola after being artificially inoculated at Kawanda, Uganda.
• In Malawi, 296 new crosses were successfully made.  These were designed to incorporate resistance to ALS, CBB, BSM, and low soil fertility in various market classes.
• Several segregating populations at various stages, ranging from F2 through F9, and fixed lines derived from crosses that combined two or more traits—grain yield; marketing seed types; and tolerance of common diseases, pests, and low soil fertility—were evaluated in Malawi.
• Several advanced lines were identified as having high levels of resistance to anthracnose.
• Cargamantos were shown to be highly susceptible to anthracnose.
• Incorporating the recessive bc 3 gene was found to be a viable alternative for breeding resistance to BCMV in the cultivar Cargamanto while preserving its commercial characteristics.

Developing Germplasm Resistant to Insects

• New crosses were made to incorporate Empoasca resistance into red-mottled beans for the Caribbean and other regions.

Incorporating Wider Genetic Diversity into Beans

• A set of Caribbean landraces was evaluated for their yield potential and resistance to CBB.
• Triple crosses between Andean and Durango beans were made to develop drought tolerance for red-mottled bush genotypes.
• About 400 advanced lines of Andean bush beans were derived from triple crosses between Andean bush and Mesoamerican climbing types. These were tested for yield potential and will be analyzed for biotic and abiotic stress tolerance.
• The highest iron content was identified, through mineral analysis, in three, multiple-parent, cross populations of Andean beans, which derived from a Cerinza/wild backcross population that has generated many commercially acceptable, large red or red-mottled, lines.
• New crosses have been made between Andean climbing beans and Durango sources of drought tolerance. A new set of 25 Andean climbing beans derived from triple crosses between Andean bush and Mesoamerican climbing types is being tested for yield potential.
• Testing of a climbing × bush bean, recombinant, inbred-line population has shown variability for climbing ability and adaptation to low P stress, through adventitious rooting and basal root length.
• Four new lines of large, red-mottled beans that are resistant to and/or tolerant of ALS, anthracnose, and root rots, and have yields superior to the best commercial cultivars were selected for regional trials.
• Six new lines of large, red, kidney beans that are resistant to and/or tolerant of ALS, anthracnose, and root rots, and have significantly higher grain yield than the best commercial cultivars (Canadian Wonder and Selian 97) were selected for regional trials.
• New lines of red-mottled, red-kidney, navy, and small-red beans with combined tolerance of low soil N and P, and/or Al toxicity were identified and entered for on-farm trials.

Output 3: Strategies developed for managing Diseases and Pests in Bean-based Cropping Systems

Characterizing and Monitoring Pathogen and Insect Diversity

• The current anthracnose differential series was shown to be incapable of discriminating between Andean and Mesoamerican isolates of the anthracnose fungus Colletotrichum lindemuthianum.
• Wild beans reveal a C. lindemuthianum population structure that appears congruent with common bean gene pools, but this is not supported by molecular data.
• The pathotype structure of C. lindemuthianum in the Departments of Antioquia and Santander, Colombia, has changed and new, more virulent, races were characterized.
• Although high genetic diversity is maintained in the CBB agent, Xanthomonas axonopodis pv. phaseoli, it is not geographically structured.
• Two variants of X. axonopodis pv. phaseoli (Xap and Xapf) are genetically sufficiently distinct to be classified into different groups.
• IGS-RFLP fragments were identified as being potentially able to distinguish between Xap and Xapf. These fragments have been cloned and sequenced, and primers are being designed and evaluated to test their potential for detecting Xap and Xapf in seed.
• Line VAX 6 is highly resistant to both Xap and Xapf.
• Specific markers could differentiate between P. griseola groups while revealing structuring according to geography and host gene pool.
• Brazilian isolates of P. griseola are all Mesoamerican and highly diverse, and differ from the Bolivian population.
• Two new viral diseases, previously unknown in common bean, emerged this year in Latin America. Their causal agents were immediately identified as a strain of Peanut stripe virus in one case, and as a phytoplasm probably transmitted by a leafhopper in the other case. Preliminary control measures were implemented in order to monitor the course of these diseases.
• Of 450 Pythium isolates, causing fungal rot, collected in Kenya and Rwanda, 206 were characterized, using RFLPs as a basis for selecting candidates for sequencing.   Twenty-four RFLP groups of isolates were formed.
• Isolates belonging to five Pythium species were shown, for the first time, to be pathogenic to beans and possibly contributing to the root rot problem of beans in eastern and central Africa.  Bean line RWR 719 had good levels of resistance to all five species.
• A bean bioassay method was developed to quantify soil inoculum of Fusarium solani f. sp. phaseoli, the pathogen causing Fusarium root rot.

Characterizing Resistance Genes for Diseases and Insects

• The current anthracnose differential series was shown to be incapable of discriminating between Andean and Mesoamerican isolates of the anthracnose fungus Colletotrichum lindemuthianum.
• Wild beans reveal a C. lindemuthianum population structure that appears congruent with common bean gene pools, but this is not supported by molecular data.
• The pathotype structure of C. lindemuthianum in the Departments of Antioquia and Santander, Colombia, has changed and new, more virulent, races were characterized.
• Although high genetic diversity is maintained in the CBB agent, Xanthomonas axonopodis pv. phaseoli, it is not geographically structured.
• Two variants of X. axonopodis pv. phaseoli (Xap and Xapf) are genetically sufficiently distinct to be classified into different groups.
• IGS-RFLP fragments were identified as being potentially able to distinguish between Xap and Xapf. These fragments have been cloned and sequenced, and primers are being designed and evaluated to test their potential for detecting Xap and Xapf in seed.
• Line VAX 6 is highly resistant to both Xap and Xapf.
• Specific markers could differentiate between P. griseola groups while revealing structuring according to geography and host gene pool.
• Brazilian isolates of P. griseola are all Mesoamerican and highly diverse, and differ from the Bolivian population.
• Two new viral diseases, previously unknown in common bean, emerged this year in Latin America. Their causal agents were immediately identified as a strain of Peanut stripe virus in one case, and as a phytoplasm probably transmitted by a leafhopper in the other case. Preliminary control measures were implemented in order to monitor the course of these diseases.
• Of 450 Pythium isolates, causing fungal rot, collected in Kenya and Rwanda, 206 were characterized, using RFLPs as a basis for selecting candidates for sequencing.  Twenty-four RFLP groups of isolates were formed.
• Isolates belonging to five Pythium species were shown, for the first time, to be pathogenic to beans and possibly contributing to the root rot problem of beans in eastern and central Africa.  Bean line RWR 719 had good levels of resistance to all five species.
• A bean bioassay method was developed to quantify soil inoculum of Fusarium solani f. sp. phaseoli, the pathogen causing Fusarium root rot. 

Developing IPM Components

• The action threshold for managing the whitefly Trialeurodes vaporariorum was validated on snap beans.
• Changes in composition of whitefly species and biotypes were monitored.
• High levels of resistance to insecticides were identified in whitefly (T. vaporariorum) and thrips (Thrips palmi) populations in Colombia and Ecuador.
• IPM components were developed and management strategies tested for whiteflies in Colombia.
• Greenhouse and field studies were conducted to determine the effect of farmyard (FYM) and green manures (GM) on soil populations of Fusarium solani f. sp. phaseoli.  The pathogen population declined with GM, but remained almost unchanged with FYM.  However, plant growth was significantly better with FYM than with GM.

Output 4: Improved Cultivars and Management Practices developed and Tested in Partnership with our African Bean Project, NARS, and Regional Networks

• The Costa Rican national program has received several F₄ populations, including the landrace ‘Sacapobres’, combined with other sources of desirable traits.
• Several partners, including NARS and the CIAT hillsides project, are increasingly turning their attention to drought resistance in Central American beans.
• Collaboration with an the Pan American Development Foundation (PADF) in Haiti is being fortified and an increasing number of materials are being evaluated there.
• Evaluation and yield testing of a collection of Colombian varieties have identified appropriate varieties for mid-altitude ecosystems to distribute to local extension workers, agronomists, and farmer-led research committees (CIALs).
• Knowledge of existing varieties and feedback from farmers on the advantages and disadvantages of these genotypes are critical to the breeding program’s success.
• Many of the seed stocks for Andean genotypes bred by CIAT’s Breeding 1 Project were at low levels and had poor germination.  We increased the seed for the DRK and CAP series and started distributing full sets to partners in the Andean Region, as well as replenishing the seed stock for cold storage.
• Support of CORPOICA is continuing in the selection of cargamanto beans with resistance to BCMV.  This support has helped refocus the breeding strategy.  Continuous support to the El Salvadorean Bean Program with resources and genetic materials bred for resistance to BCMV and BGYMV has facilitated the characterization and release of new, red-seeded, bean genotypes in that region.
• Collaborating farmers in pilot sites in Uganda acquired knowledge on recognizing and differentiating bean diseases, and understanding the effects of their indigenous seed management practices on seed quality and production.
• Participatory variety selection involving four farmer groups in southwestern Uganda resulted in a selection of a relatively high number of entries (44 out 68) from the root-rot nursery for evaluations in communal and individual plots.
• Increasing farmers’ knowledge about the biology and ecology of the major pests affecting their bean crops has enabled them to develop appropriate management practices.
• Farming communities have been empowered to make IPM decisions with a focus on indigenous knowledge systems, and to rediscover value in their traditional IPM strategies.
• Several nurseries and germplasm were distributed to bean network partners.
• A new, wider, strategy for impact was developed to disseminate bean-based technologies to 10 million people in eastern, central, and southern Africa.
• Eighteen national programs in eastern, central, and southern Africa were trained in developing promotional materials and to start implementing a new strategy for disseminating bean-based technologies to 10 million people.

Collaborative Projects Developed and Executed with NARS and Regional Networks; and Strengthening Capacity in NARS and Regional Networks

• CIAT scientists participated in the planning of activities for PROFRIJOL, the Andean Region, and African networks.
• National scientists were given individual training.
• To achieve regional food security, the ECABREN conceptual framework was harmonized with other ASARECA networks and with the USAID/REDSO results-oriented framework.
• ECABREN was extended for another 3-year phase, from October 2003 to September 2006, with USAID financial assistance.
• NARS scientists took responsibility for managing activities within the PABRA framework.
• The SABRN network  continued to build its strength within the SADC region, building on experiences from ECABREN by launching more cross-network activities, while continuing the strategies approved by the steering committee in 2001 that placed increased emphasis on creating wider impact in the region through bean-based technologies.
• Regional germplasm exchange of improved cultivars has led to the release of two market-led varieties: SUG 131 (sugar bean) and UBR92 (25) (navy bean) in Malawi.  These two bean varieties join the list of CIAT-bred varieties that have been released in the SADC region.  Other countries like Swaziland and Zimbabwe have also shown interest in the sugar bean variety.
• Joint collaboration and concept notes were prepared.

Supporting NARS and Regional Network Researchers on Soil and Crop Management 

• A Bolivian partner evaluated a set of 10 genotypes for local adaptation, and identified two bred lines (DOR364 and BAT 881) and one germplasm accession (G 21212) as promising.

Supporting Human Resource Development in NARS and Regional Networks  

• CIAT bean project scientists are actively participating in international conferences and meetings.
• National and international scientists and students received individual and group training.
• The Web page for Project IP-1, adapted to the new Web site at CIAT, can now be accessed through the address http://www.ciat.cgiar.org/beans/index.htm
• Three national scientists from Rwanda were offered individual training at Kawanda (Uganda) on research methods for plant diseases.
• A series of farmer-training programs was conducted on IPM (Tanzania, Kenya, and Malawi), seed quality, and root rots (Uganda).
• NARS scientists acquired knowledge and skills in producing bean promotional materials.
• Network collaboration in research and development activities was reinforced among scientists and development partners.
• The African bean networks and CIAT organized two workshops for discussing experiences and research results.
• CIAT scientists participated in several regional and international workshops and conferences.