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

[Goals] [Outputs]

Goals

• Higher and stable bean production with less dependency on inputs such as pesticides, fertilizers, and water.
  
• Integration of traditional and advanced (e.g., marker-assisted selection) crop-improvement techniques with farmer participatory research approaches to facilitate rapid adoption of improved bean cultivars.
  
• Institutional and organizational capacities of NARS, and regional and community organizations strengthened.
  
• Increased access and adoption rates of bean-based technologies through NARS, networks, and farmers.

Outputs

• Improved, small-seeded, bean germplasm that is resistant to major biotic and abiotic stresses and has greater nutritional and market value
• Improved, large-seeded, bean germplasm that is resistant to major biotic and abiotic stress factors, and has greater nutritional and market value
• Strategies developed for managing diseases and pests in bean-based cropping systems
• Improved cultivars and management practices developed, evaluated, and widely disseminated in partnership with NARS, regional networks, NGOS, and farmers
• Strengthened the institutional, organizational, and collaborative capacity of NARS and subregional networks in Africa and Latin America
  

Output 1: Improved, Small-seeded, Bean Germplasm that Is Resistant to Major Biotic and Abiotic Stresses and Has Greater Nutritional and Market Value

Developed Germplasm Tolerant of Abiotic Stresses (Drought and Low Soil Fertility)

• More than 170 drought-tolerant F₈ lines were identified from a second cycle of crosses to combine drought tolerance and resistance to bean golden-yellow mosaic virus (BGYMV). Compared with lines available in previous years, many of these have superior grain color (red, black, carioca, and mulatinho) and size (as large as 35 g/100 seeds).
  
• Field evaluation of 121 recombinant inbred lines (RILs) of the cross MD 23-24 × SEA 5 over two seasons resulted in the identification of a line (MR 81) that was superior in its adaptation to drought. Its superior performance was associated with higher values of pod harvest index, seed harvest index, and seed TNC content; a lower proportion pod-wall biomass; and lower values of seed P content. These results indicated the importance of increasing the mobilization of photosynthates to pods and seeds per unit of seed P in common beans under rainfed conditions.
  
• Screening for aluminum resistance under hydroponic conditions, based on total root length per plant and number of root tips per plant, resulted in the identification of four accessions of Phaseolus coccineus (G 35025, G 35066, G 35621, and G 35341) that were markedly more resistant to aluminum than were P. vulgaris genotypes.
  
• Evaluation of 14 families of P. coccineus for resistance to aluminum under hydroponic conditions resulted in the identification of six families (G 35346-2Q, G 35464-5Q, G 35066-1Q, G 35066-5Q, G 35346-3Q, and G 35066-4Q) and an accession (G 35066) as relatively more resistant to aluminum.
  
• Greenhouse screening for tolerance of low phosphorus in 30 RILs of the cross BAT 477 × DOR364 (with four checks) resulted in the identification of four RILs (BT21138-69, BT21138-115, BT21138-124-1-2, and BT21138-124-1-3) and a germplasm accession (G 21212) that were superior in their adaptation to low P supply. The superior performance of these five genotypes was associated with greater values for total root biomass, total root length, and specific root length, indicating increased root vigor with low P supply.
  
• Climbing bean genotypes showed better nodulation with native rhizobia than did bush bean genotypes. Nodulation varied considerably among 120 bean genotypes, with average nodule number per plant varying from 16 to 58 among bush bean genotypes and from 14 to 100 among climbing bean genotypes.
• Inoculation with three rhizobia strains significantly increased nodulation and grain yield in both types of beans. However, the genotypes showed specificity for rhizobia strains, thus influencing effective symbiosis.

Developing Germplasm with Multiple Resistance to Diseases

• From the VEF2004 nursery, 13 genotypes were identified as having moderate levels of resistance to several races of angular leaf spot (ALS) and anthracnose, and two pathogens of common bacterial blight (CBB).
  
• Several advanced lines of small reds and blacks had high levels of resistance to pathogens of ALS, anthracnose, and CBB.
  
• Although we confirmed the resistance of BAT 447, BAT 332, CG/82-69, BAT 868, H6 Mulatinho, CG/82-24, and A 300 to Macrophomina phaseolina, we also showed that using mixtures to evaluate for charcoal rot resistance is not efficient, and that individual isolates should be used.
  
• Several lines with resistance to bean common mosaic virus (BCMV) and BGYMV were identified.
  
• Excellent drought tolerance was confirmed in advanced lines containing the bc-3 gene for recessive resistance to bean common mosaic necrosis virus (BCMNV) and severe mosaic virus.
  
• Studies on the transmission of the new begomovirus disease (bean leaf crumple virus) revealed that the A biotype of Bemisia tabaci is a more efficient vector than the B biotype.

Developing Germplasm with Resistance to Insect Pests

• Resistance to the bean weevil (Acanthoscelides obtectus) was identified in P. vulgaris × P. acutifolius hybrids.
  
• An index was developed for selecting bean lines tolerant of the leafhopper Empoasca kraemeri.
  
• New accessions and lines with insect resistance were identified.

Developing more Nutritious, Small-seeded, Bean Varieties

• An improved selection procedure, involving the analysis of minerals in early generation bulks across environments, appears to have improved the effectiveness of selection for high minerals in the derived families.
  
• High levels of iron were confirmed in selections from a P. polyanthus (G 35575) and P. coccineus accession (G 35999). Interspecific crosses have been initiated.
  
• Progress was made in quantifying iron and zinc contents in selected bean lines.
  
• Soil and foliar applications of iron were shown to depress yields.
  
• Soil applications of zinc were shown to increase yield, whereas foliar applications can depress grain yields.
  

Output 2: Improved, Large-seeded, Bean Germplasm that Is Resistant to Major Biotic and Abiotic Stress Factors, and Has Greater Nutritional and Market Value

Developing Germplasm Resistant to Diseases

• Six advanced lines (HGA 10, HGA 11, HGA 15, HGA 21, HGA 26, and HGA 27) showed high levels of resistance to the charcoal rot pathogen. Two of these lines (HGA 26 and HGA 27) were previously identified as being highly resistant to the pathogens causing rust, CBB, anthracnose, and ALS.
  
• Immunity to BCMNV-NL3 was found in 46 of 108 RILs segregating for the bc-3 gene.
  
• Several bean lines with multiple resistance to Pythium root rot and ALS have been selected and will be distributed to different countries for multi-site evaluations. Some have already been distributed to Kenya and Malawi.
  
• A SCAR marker associated with the ALS-resistance gene in MEX 54 has been successfully used in selecting for ALS resistance.
  
• A collaborative mechanism has been set up to facilitate national partners' integration of marker-assisted selection into their breeding program.
  
• New red kidney lines with improved resistance to root rots, ALS, anthracnose, and rust, and yield potential were identified from intra- and inter-gene pool crosses with the susceptible commercial cultivars Canadian Wonder (GLP-24) and Selian 97.
  
• New red mottled lines with resistance to ALS, root rots, anthracnose, and Fusarium wilt, and possessing commercial grain type were identified from crosses with GLP-2.
  
• New lines with improved resistance to anthracnose, root rots, rust, and ALS, and improved yield potential were identified from populations derived from inter-gene pool crosses with the susceptible commercial cultivar Lyamungu 85.
  
• New red mottled lines with improved resistance to root rots, ALS, anthracnose, and rust, and improved yield potential were identified from intra- and inter-gene pool crosses with the susceptible commercial cultivar Lyamungu 90.
  
• Several individual selections homozygous for the bc-3 gene were identified in the highly-prized 'cargamanto' Andean genotype.
  
• Several elite lines and germplasm were screened for the presence or absence of the I-gene. Donor parents were identified and a breeding program initiated to improve resistance in selected useful materials against BCMNV.
  
• Collaboration with the Universidad Nacional de Colombia focused on using marker-assisted selection for BCMV resistance in large red-seeded climbing beans. The SCAR markers ROC11 for the bc-3 gene and SW13 for the I-gene were used in this work and built on last year's selection of anthracnose resistance genes.
  
• Over 2000 populations and lines at different generations (F₁-F₆) and in various market classes were observed, selected, and advanced to the next generation during this reporting period.
  
• Several lines were selected from the dark red kidney, cream mottled (sugar), brown/tan (khaki), red mottled (calima), and small white (navy) bean market class nurseries. These lines combined attributes such as high yield with resistance to more than one of these diseases: CBB, ALS, and floury leaf spot (FLS). These will be available for distribution to NARI partners within the SABRN.
  
• A marker has been developed by the Republic of South Africa's NARS for the newly identified rust resistance gene Ur-13. This marker will be useful for pyramiding this gene with other resistance genes to which it is hypostatic.
  
• Advanced lines of BCMV-resistant bush and climbing beans were developed through marker-assisted selection and tested for yield.
  
• A new series of BCMV-resistant climbing beans (MBC lines) was developed and distributed to partners in Africa and Latin America.

Developing Germplasm with Resistance to Insects

• A set of nine molecular markers (SCARs and CAPS) were developed for screening for resistance to Apion godmani through bulked segregant analysis and genetic mapping. A hypothesis for the inheritance of resistance was discussed in a recent publication.

Incorporating Broader Genetic Diversity into Beans

• Levels of drought tolerance in bred Andean lines are significantly higher than for the commercial cultivar COS 16, and are approaching those for the Mesoamerican check genotype SER 16.
  
• A series of advanced lines were developed to introduce greater diversity from Mesoamerican climbing and semi-climbing beans or CBB-resistant sources into large, red-seeded, Andean climbing beans.
  
• Drought and high temperature screening was conducted during the dry season at CIAT headquarters to identify Andean beans that can serve as sources of drought and heat tolerance. A set of promising large red and red mottled genotypes were identified to constitute a nursery for testing with network and NARS partners in Kenya, Malawi, and Zimbabwe.

Developing more Nutritious, Large-seeded, Bean Varieties

• We continued to evaluate diverse accessions from various regions of Colombia to determine variability for high iron and zinc traits in regional landraces.
  
• In the breeding program, a set of advanced climbing-bean lines developed from the high iron source G 14519 were tested for seed mineral accumulation across three sites and data analyzed to determine the lines with the highest concentrations of iron and zinc. These lines would become part of a nursery established specifically for climbing beans. Some of the lines showed heat tolerance during selection at CIAT headquarters. General adaptation was tested by evaluation at the two other sites.
  
• Tannins were purified from representatives of commercial classes of common beans to derive standard curves for tannin concentration specific to each seed-coat color class. This increased our accuracy of tannin measurements.
  
• The first estimates of genotype × environment interaction for tannin content were obtained and showed greater location effects for soluble than for insoluble condensed tannin fractions. Findings also showed that location × genotype effects were minimal and not significant for the above-mentioned fractions, as well as for total content.
  
• Phytate concentration was measured for the first time at CIAT as a prelude to QTL mapping of this trait. Interesting differences were observed among the mapping population's parents.
  
• A crossing block for nutritional improvement of bush and climbing beans from Africa and Latin America has generated 153 new simple, triple, double, and backcross combinations. We used landraces with high iron contents, the breeding lines mentioned above, and BCMV-resistant climbing beans from the MBC series. This built on the 120 simple-cross combinations made last year and which have now advanced to F₃₊ generations.
  
• In collaboration with FIDAR, a fertilization experiment was conducted, using three Andean genotypes to measure the effect of foliar and soil treatments on seed iron and zinc contents.
  

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

Characterizing and Monitoring Pathogen and Insect Diversity

• Significant advances were made in characterizing new viruses affecting bean production in Colombia, Mexico, Argentina, and Brazil.
  
• Pathotype 63-63 of the ALS pathogen, Phaeoisariopsis griseola, was identified for the first time in Quilichao, Colombia, revealing changes in the pathogen's population structure and the value of continuously monitoring the pathogen in our experiment site.
  
• An efficient transformation protocol for Ph. griseola was developed. It consistently gives >50 transformants per 10⁵ conidia/mL, thus opening the doors for the biotechnological analysis of this pathogen.
  
• Several T-DNA tagged mutants of Ph. griseola were created, using the Agrobacterium tumefaciens-mediated transformation (ATMT) protocol. Initial mutant characterization identified seven transformants that had lost their ability to cause disease on susceptible genotypes (pathogenicity mutants). These mutants form an important tool for elucidating host-pathogen interactions that result in disease expression and later identifying fungal genes that determine avirulence versus virulence.
  
• A thermal, asymmetric, interlaced PCR (TAIL-PCR) protocol for isolating the fungal sequences flanking the T-DNA insertion point was optimized and used to isolate sequences of the pathogenicity mutants of Ph. griseola.
  
• We developed four cDNA libraries (two of which were subtracted) from events of compatible and incompatible Ph. griseola × P. vulgaris interactions. The cDNA libraries each have 1500 clones, while the subtracted libraries have 780 clones. These libraries form an important tool for molecular analysis and identifying the plant and fungal genes needed to express resistance or susceptibility in the bean × Ph. griseola interaction.
  
• Preliminary analysis of cDNA from compatible and incompatible interaction events identified transcripts with homology to genes known to be involved in resistance to anthracnose (Prf and Co-4).
  
• Three major intercrops of beans (maize, sorghum, and peas) in the bean-based cropping system of southwestern Uganda were affected by root rots. This finding implied that they may be hosts to the pathogens.
  
• Management options that are effective for bean root rots also benefit other crops such as sorghum and field peas in bean-based cropping systems. Hence, management strategies for root rots should be formulated on a systems basis rather than on a crops basis.

Characterizing Genes for Resistance to Diseases and Insects

• Resistance genes in G 19833 were shown to be distinct from those in the Andean genotypes Michigan dark red kidney, Kaboon, and Perry Marrow. They may comprise a new Andean resistance locus.
  
• The PF9-G1 SCAR marker is linked to the resistance gene in G 10474 and can be used to select this resistance gene in beans of Andean and Mesoamerican backgrounds.
  
• We identified and developed SCAR markers linked to the Pythium root rot resistance gene in bean line RWR 719. This is the first time that a marker has been developed for a gene for resistance to Pythium root rot.
  
• Preliminary analysis of the allelic relationships between different sources of resistance to ALS revealed the complex nature of that resistance. More information will be obtained on completing these studies and mapping the markers linked with ALS resistance genes.
  
• Resistance to ALS in MEX 54 is controlled by a single dominant gene and was expressed in the progenies of two yellow bean cultivars.
  
• F₂ and backcross populations, segregating for resistance to ALS, were developed, and F_2.3-derived lines selected.
  
• A set of parental genotypes for geminivirus resistance and drought tolerance were evaluated with conserved orthologous sequence (COS) markers.

Developing Components for Integrated Disease-and-pest Management

• Mulching with green manures increased yields of susceptible bean cultivars. This increase was associated with reduced root-rot incidence and increased availability of soil nutrients.
  
• Important changes in whitefly species composition in the targeted area were detected.
  
• Whiteflies were found to have varying levels of resistance or susceptibility to some of the insecticides commonly used for control in the targeted area.
  
• Continued and expanded diffusion of technology activities within the DFID-funded project on the "Sustainable Management of Whiteflies".
  
• Losses of snap beans to the new virus (bean leaf crumple virus) were measured.
  
• Conducted successful screening for sources of resistance to the new viral disease affecting snap beans.
  
• Several Pythium spp. were recovered from crops grown in association with beans. The most frequently occurring species was P. ultimum.
  
• Mortierella sp. (strain MS10) was shown to have antagonist effects on pathogenic Pythium isolates with marked reduction in disease severity in screenhouse studies, thus demonstrating potential as a biocontrol agent against Pythium root rot.
  
  

Output 4: Improved Cultivars and Management Practices Developed, Evaluated, and Widely Disseminated in Partnership with NARS, Regional Networks, NGOS, and Farmers

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

• Many breeding line nurseries and germplasm were distributed to bean network partners from CIAT headquarters.
  
• The national bean research program in the southern highlands of Tanzania released a BILFA line this year, calling it 'Uyole 04'. Zambia released the variety Kalunga, while Malawi released three varieties: BCMV-B2, BCMV-B4, and F7 BC D/O 19, which were developed in partnership with the Bean-Cowpea CRSP. The Republic of South Africa released 'Teebus-RCR-2', which is resistant to rust, CBB, ALS, and BCMNV.
  
• The high iron NUA (Spanish code for Andean nutrition) breeding lines developed 2 years ago entered seed multiplication and extensive on-farm testing in Valle, Cauca, and Nariño in Colombia.
  
• Close collaboration between CIAT and breeding programs in countries of the Andean region continued, with exchanges of researchers and germplasm. Training programs were developed for researchers from the Universidad Nacional in Colombia and the Universidad Mayor de San Simón in Bolivia. With the first group, we intensified selection of BCMV and anthracnose resistance in climbing beans, using molecular markers.
  
• Breeding line nurseries were distributed to partners in Bolivia, Colombia, Ecuador, Peru, and Venezuela. The red mottled and small-grained nutrition nurseries were distributed to FONTAGRO project partners.
  
• Advanced drought-tolerant lines showed 23%-26% yield increase over checks, and tolerance of diseases in trials under moderate to severe drought for three seasons in eastern Africa.
  
• Twelve lines that matured earlier than 30 commercial varieties were identified in eastern Africa. These lines had matured within 70 days, providing a drought escape mechanism for farmers and a source of earliness for breeding programs.
  
• Three RMA lines showed a yield advantage of up to 12% over the best red mottled commercial check (GLP-2) in trials conducted across five environments in eastern Africa. These lines also showed resistant reactions to ALS, anthracnose, rust, and root rots under field conditions.
  
• Ten mid-altitude climbing-bean lines showed yield advantage of up to 21% over the best check variety in trials conducted across four environments in eastern Africa. These lines showed good levels of field resistance to ALS, anthracnose, rust, and root rots, and produced preferred grain types.
  
• Eight low-soil-fertility tolerant lines, selected from segregating populations, showed yield advantage of up to 32.1% over the best check under nutrient-stressed conditions in trials conducted at three locations over two seasons in eastern Africa.
  
• Nutrient stress reduced grain yield by 38.6% and seed size by 10.4%. One low-soil-fertility tolerant line (BF 13573-46Q) showed the lowest yield reduction (16.9%) under nutrient-stressed conditions and performed well under non-stress conditions.
  
• Seventeen bush and five climbing-bean candidate lines, contributed by public and private institutions, were evaluated in the pre-release national performance trials at six sites in Kenya during 2005.
  
• In Uganda, two lines RWR 2075 and RWR 1946, tolerant of low soil fertility and root rots, reached the pre-release level.
  
• In the Democratic Republic of the Congo (DRC), seven bush and five climbing-bean varieties were rated as acceptable by farmers and are candidate lines for release.
  
• In Rwanda, nine bush and five climbing-bean lines showed improved performance in multi-site trials at four sites under severe disease pressure, and under drought at one site.
  
• In Madagascar, 8 small red, 10 red mottled, and 6 kidney lines performed better than local checks.
  
• Fast track lines with moderate to high concentrations of iron and zinc in grains were evaluated for adaptation and agronomic traits in five countries.
  
• Seven lines in Rwanda, six in DRC, and one in Uganda performed better than did local checks. They were selected for wider evaluations.
  
• Women and men farmer evaluators for fast track lines in DRC indicated that AFR 708, MLB-49-89A, and AND 620 are acceptable.
  
• We collected 524 germplasm accession lines in the first year in four countries, working towards a final target of 2000 accessions.

Developing Sustainable Seed Systems for Wide Dissemination

• A positive attitudinal and policy change towards decentralized seed systems appears to have become widespread in collaborating countries.

Socioeconomic Activities

• The Modified Farmer Field School (MFFS) approach proved invaluable for enabling learning among beneficiaries of integrated pest-and-disease Management recommendations.
  
• Constraints limiting bean production as a commercial enterprise were identified and grouped into production and marketing categories.
  
• Recommendations focused on improving policy issues to create environments that would facilitate cost-effective bean production and marketing at all levels in the bean value chain.
  

Output 5: Strengthened the Institutional, Organizational, and Collaborative Capacity of NARS and Subregional Networks in Africa and Latin America

Strengthened the Capacity of NARS by 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 four MSc candidates and four undergraduate students completed their research theses. In Africa, one PhD and four MSc candidates completed their research theses.
  
• The Pan-African Bean Research Alliance (PABRA) continued to support students at the MSc level in plant breeding, integrated pest management, and integrated nutrient management. The Alliance also supervised thesis research of students supported by the Rockefeller Foundation and Bean-Cowpea CRSP.
  
• Several scientists from the ECABREN and SABRN regions participated in training programs and gained skills in several areas. These included bean breeding (20), participatory monitoring and evaluation (35), principles and application of decentralized seed systems (314), innovation histories of the adoption of bean varieties (16), principles and practices of marker-assisted selection (13), and participatory plant breeding and variety selection (26).
  
• For the first time, scientists from West Africa (Cameroon) participated in the PABRA technical planning workshop.
  
• The PPB and PVS approaches are influencing institutional changes in bean-breeding foci and approaches in southern Africa.
  
• Several PPB varieties have been released by Ethiopia and northern Tanzania. Two more from southern Uganda will be submitted for release.
  
• As of May 2005, over 50% (27 scientists out of a total of 53) of the plant breeders in ECABREN and SABRN networks are employing participatory approaches in variety selection and breeding.
  
• Catalogs of preferred varieties were developed by farmers and are being distributed to farmer groups and village information centers.
  
• Researchers have used the PPB collaboration to expose farmers to new kinds of diversity and opportunities, which has created new and lucrative market niches in both southern Ethiopia and southwestern Uganda.
  
• Two breeders and a pathologist from headquarters in Colombia traveled to Africa and participated in the training of breeders and development of joint project ideas.
  
• Several courses and workshops were held in Latin America: the agronomic and integrated disease management of snap and dry beans, Bogotá, Colombia (65), management of whiteflies (20), biology and ecology of whiteflies (67+), sampling insects and biology of whiteflies (92+), sampling methods (8), measuring parasitism in whiteflies (1), and breeding common bean for nutritional value and drought tolerance (35).

Collaborative Projects Developed and Executed with NARS and Regional Networks

• A snap bean project submitted to ASARECA-CGS was approved for Funding Stream A (NARS) over 3 years to enhance competitiveness of snap bean for domestic and export markets.
  
• The nutrient-rich bean project was reviewed and approved by the ASARECA-CGS technical support group for Funding Stream B, starting March 2005.
  
• Three concept notes of regional importance were developed with network partners and submitted in response to ASARECA's second call for concept notes.
  
• A policy pre-proposal on the value of bean exports was discussed and approved for funding by ASARECA-ECAPAPA.
  
• A project on the promotion of integrated pest-and-soil management strategies for Phaseolus beans in smallholder farming systems in Malawi, Mozambique, and Tanzania was submitted to the McKnight Foundation.
  
• Three concept notes were developed and submitted in response to ASARECA/FARA's call for concept notes on the Lake Kivu Pilot Learning Site of the sub-Saharan Africa Challenge Programme. The notes were on (1) bean-banana-based system, (2) IPM in the bean-potato system, and (3) an agroenterprise project with snap and dry bean components to be developed by a variety of partners, including PABRA partners.
  
• A project on "Biofortified Crops for Improved Human Nutrition" of the Harvest Plus Challenge Program continued with funding by the World Bank, DANIDA, Denmark, and the Gates Foundation (USA).
  
• A project to diffuse results on whitefly control was approved and initiated with partners throughout the tropics.
  
• A project on biofortifying maize, beans, rice, and sweetpotato, and including postharvest processing advanced in its organization, widely testing quality-protein maize (QPM) with the active involvement of Latin American bean breeders. The larger continent-wide project is bolstered by two smaller projects. Nutrition projects have enabled the revitalization of regional cooperation.
  
• Drought-tolerant beans, developed under a German-funded project, were shared with breeding programs in 10 Latin American countries.

Strengthened International Collaboration through Networks (Intra- and Inter-network Collaboration) and/or Bilateral Relations

• A Latin American breeder's workshop was held in Cali to revive cooperation among programs.
  
• A seed specialist was contracted to promote diffusion of biofortified crops in Central America.
  
• A harmonized ECABREN framework with four expected results was developed, facilitating standardized reporting for all ASARECA networks.
  
• Four FutureHarvest Centers (CIAT, CIMMYT, ICRISAT, and IITA), together with SSSN, continued to team up and sensitize various stakeholders on sustainable ways to produce and distribute seed of open- and self-pollinated crops in Swaziland and Lesotho.
  
• The strategy for IPDM and INM in the PABRA region was reviewed.