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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 Tolerant of
the Abiotic Stresses of Drought and Low Soil Fertility
- Breeding lines with commercial grain type and selected
for tolerance of terminal drought in previous years also
expressed tolerance to intermittent drought, exceeding the
commercial checks by 200% or more in yield.
- New drought-tolerant lines showed as much as 42% yield
improvement over local commercial cultivars under both stressed
and non-stressed conditions in eastern Africa.
- Field evaluation of 16 elite lines showed that one of
the bred lines (SEA 15) was outstanding in its adaptation
to drought. The superior performance of this line under
drought, compared with 15 other elite parents of recombinant
inbred lines (RILs), was associated with lower seed ash
(mineral) content, indicating efficient use of acquired
nutrients for grain production.
- Among the 95 advanced lines of the cross BAT 881 ×
G 21212, three lines (BH 21134-9-1-1-M-M-M-M; BH 21134-154-1-1-M-M-M-M-M;
BH 21134-97-1-1-M-M-M-M-M) were superior in their adaptation
to drought. Their superior performance was related to lower
levels of seed ash (mineral) and seed P, indicating the
usefulness of these traits for selection for drought adaptation
in common bean.
- Among the 95 advanced lines of the cross BAT 881 ×
G 21212, three lines (BH 21134-110-1-1-M-M-M-M-M; BH 21134-144-1-1-M-M-M-M-M;
BH 21134-30-1-1-M-M-M-M-M) were outstanding in their adaptation
to acid soil. These three lines were markedly superior in
seed yield to BAT 477, a standard check for abiotic stress
adaptation, but inferior to the parent, G 21212.
- Lines bred for tolerance of low soil fertility yielded
65%-75% more than a good commercial check across three fertility
stressed environments.
- Evaluated 30 advanced lines and parents of the cross BAT
477 × DOR364 for tolerance of low soil P. One parent
(BAT 477), one landrace (G 21212), and two lines (BT 21138-124-1-3-M-M-M-M
and BT 21138-98-1-1-M-M-M-M-M) were superior. Of these four
genotypes, BT 21138-98-1-1-M-M-M-M-M was outstanding in
using P and N for grain production.
- Implemented a screening procedure to evaluate genotypic
variation for low-P adaptation in common bean, and showed
that three "per plant" traits (total number of
basal roots, total root length, and total number of root
tips) could serve as screening tools to identify low-P adapted
genotypes.
- Implemented a screening procedure to evaluate genotypic
variation for Al resistance in common bean. Four traits
showed that they could serve as screening tools to identify
Al-resistant genotypes: percent inhibition of root elongation,
percent increase of average root diameter, total root length
per plant, and total number of root tips per plant.
- Identified a QTL that is associated with better symbiotic
N fixation under P-stressed conditions, contributing as
much as 49 kg/ha to yield, that is, the equivalent of 8%
total yield in a low yield environment.
Developing Germplasm with Multiple
Resistance to Diseases
- The sources of resistance to BGYMV, identified by PROFRIJOL
and CIAT, continue to be effective for pyramiding genes
for golden yellow mosaic resistance into new common bean
cultivars.
- A marker for a second gene widely used for resistance
to BGYMV, was incorporated into the breeding program.
- The CIAT virologist helped diagnose a new viral disease
affecting snap beans in Valle de Cauca, Colombia.
- Successfully screened sources of resistance to the new
viral disease attacking snap beans.
- Demonstrated the feasibility of producing snap beans with
a 70%-75% reduction in insecticide use.
- Showed that 14 recombinant inbred lines (RILs) from the
DOR364 × G 19833 cross combined resistance to several
P. griseola and C. lindemuthianum pathotypes,
including the most virulent races.
- Also showed that 16 advanced lines, constituting small
blacks and small reds, had resistance to the most virulent
race (63-63) of P. griseola.
- Confirmed the effectiveness of the ALS-resistance sources
G 10909 and G 10474 against a distinct set of pathogen races
in Darien. In contrast, these races broke the resistance
of G 10613.
- Eighteen new navy (small white) bean lines with resistance
to rust gave significantly higher seed yield than five regionally
important commercial cultivars.
- Thirteen new rust-resistant pinto lines outyielded the
best commercial cultivars by as much as 58%.
Developing Germplasm with Resistance
to the Pests Thrips palmi, Leafhopper, Pod Weevil,
and Bruchids
- Studies completed on antibiosis, tolerance, and antixenosis
as mechanisms of resistance to Thrips palmi.
- Located a major QTL for Thrips palmi resistance
on chromosome b06. Also located other minor QTLs for thrips
resistance (see also SB-2 Report).
- Identified resistance to the bean weevil (Acanthoscelides
obtectus) and leafhopper (Empoasca kraemeri)
in Phaseolus vulgaris × P. acutifolius hybrids.
- Studies completed on the development of a DNA-based molecular
marker for resistance to the Mexican bean weevil (Zabrotes
subfasciatus).
- Progress made in developing molecular markers for resistance
to the pod weevil (Apion godmani).
Developing More Nutritious, Small-seeded,
Bean Varieties
- Identified new bean lines high in iron and zinc concentration
in eastern Africa. More than 20 farmers evaluated them for
agronomic characteristics.
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PDF Documents:
Annual Report 2003
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Output 2: Improved, Large-Seeded, Bean
Germplasm Resistant to Major Biotic and Abiotic Stress Factors,
and Combined with Greater Nutritional and Market Value
Developing Germplasm with Resistance to Diseases
- Incorporating the recessive bc-3 gene for resistance
to bean common mosaic/necrosis proved to be a viable methodology
for bean genotypes expressing genetic incompatibility with
dominant sources of common mosaic resistance.
- Identified new sources of BGYMV resistance in the Mesoamerican
race of P. vulgaris.
- This year, we started marker-assisted selection (MAS)
for BCMV resistance in Andean bush and climbing beans. Used
two markers to evaluate almost 2000 lines: ROC11 for the
bc-3 gene and SW13 for the I gene. The bc-3
marker worked especially well for climbing beans, and resulted
in substantial savings in area planted. This work builds
on last year's success in using SCAR markers for common
bacterial blight (CBB), and for bgm-1 and QTLs for
resistance to bean golden yellow mosaic virus (BGYMV) that
were introgressed into advanced breeding lines of red mottled
seed type. These lines were tested for yield this year.
- Identified several advanced lines with high levels of
anthracnose resistance.
- Evaluation of nurseries of mid-altitude climbing beans
and other red-mottled seed types for resistance to Pythium
root rot and ALS led to identification of lines resistant
to both diseases and with potential for direct use.
- Used 44 Andean, Afro-Andean, and Mesoamerican races of
P. griseola from all over Kenya to evaluate resistance
of lines belonging to major market classes grown in Africa.
- Created several new populations designed to transfer,
combine, and pyramid resistance to ALS, Pythium root rot,
Fusarium wilt, and anthracnose into major, locally adapted,
commercial bush and climbing bean cultivars susceptible
to these diseases.
- Made over 1000 single-plant selections from F3 families
derived from simple crosses. Multi-site evaluations are
being planned to obtain families that are resistant to Pythium
root rot and possessing farmer-preferred characteristics.
- Identified 26 climbing bean lines with combined or specific
resistance to CBB, BCMV, and web blight in eastern Africa.
- Ten new mid-altitude climbers outyielded regionally important
check cultivars (Umubano and Vunikingi) by as much as 39%
in eastern Africa.
- Nine red-mottled seed type lines with multiple disease
resistance showed a yield advantage of as much as 20%, compared
with the best of 10 regionally important red-mottled seed
type commercial cultivars.
- More than 70 farmer groups in 22 districts in Kenya evaluated
elite bean cultivars and advanced breeding lines in participatory
variety selection trials, and started community based seed
bulking.
- Sixteen new red kidney lines showed a yield advantage
of more than 500 kg/ha over the commercial cultivars in
regional trials in eastern Africa.
- A total of 2097 F3-F5 families derived from single-plant
selections are available for distribution. These cover four
market classes (red mottled, sugar, brown/tan, and red kidney),
and were developed to include three or more important traits
(market class, ALS, CBB, low soil fertility, and/or bean
stem maggot).
- Identified 22 lines for adaptation to Malawian conditions
from the international ALS nursery distributed by CIAT (Colombia).
- Made available 71 selections from the mid-altitude climbing
bean nursery distributed by CIAT (Colombia) for further
evaluation with partners in Malawi and the SADC region.
Developing Germplasm Resistant to Insects
- Developed new lines incorporating insect resistance.
- Tested advanced lines derived from red-mottled seed type
and Empoasca-resistant parent for yield. Applied
two DNA markers for arcelin-derived resistance to bruchids
in the selection of over 800 advanced lines. These markers
showed promise for substituting the serology-based assays
currently used for marker-assisted selection. The best advanced
lines from this exercise were tested for yield this year
and included new bruchid-resistant beans of the red mottled,
large red, light red kidney, and white kidney Andean genotypes.
These lines will be useful for the Caribbean and other tropical
regions where insect pressure, especially from Empoasca
spp. in the field and bruchids in storage, is severe.
Incorporating Wider Genetic Diversity into Beans
- Selected cargamanto beans (cream-mottled, climbing beans)
for mid-altitude adaptation, and conducted generation means
analysis of climbing × bush bean populations. The
goal was to determine trait correlations and heritabilities
in climbing beans, and thus facilitate the future breeding
of improved climbing beans.
Developing more Nutritious, Large-Seeded, Bean Varieties
- Used mineral analysis to identify the highest iron content
in a collection of Andean beans from the Department of Nariño,
Colombia. This analysis helped identify potential genotypes
to include in a nutrition nursery.
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Output 3: Strategies Developed for Managing
Diseases and Pests in Bean-Based Cropping Systems
Characterizing and monitoring pathogen and insect diversity
- Detected and partially characterized at the molecular
level a new whitefly-transmitted virus that attacks common
bean in Colombia. Sources of resistance have already been
identified.
- Showed that the ALS pathogen P. griseola coevolved
with common bean gene pools and exhibits extensive geographical
differentiation.
- Showed that co-infection of common bean by different races
of P. griseola occurs under field conditions.
- Showed that the pathotype structure of C. lindemuthianum
in the Departments of Antióquia and Santander, Colombia,
has changed, and new, more virulent, races were characterized.
- Showed molecular evidence that the bean anthracnose pathogen,
C. lindemuthianum coevolved with the gene pools defined
for common bean.
- Characterized 30 Pythium isolates from Uganda and
Kenya by sequencing the ITS-1 region of ribosomal DNA. The
isolates were grouped into 12 species, 7 of which were new
as bean pathogens.
- Developed distribution maps for Pythium species
characterized in Uganda.
Characterizing Disease and Insect Resistance Genes
- At least three resistance genes condition the resistance
of G 19833 to four races of C. lindemuthianum.
- The resistance genes in G 19833 are distinct from those
in the Andean genotypes Michigan dark red kidney, Kaboon,
and Perry Marrow, and may be a new Andean resistance locus.
- Successfully converted two AFLP markers to STS markers,
and developed protocols for their use in MAS.
- Identified six new AFLP markers segregating with resistance
genes in G 10474, G 10909, MAR 1, and MEX 54.
- Both dominant and recessive genes with epistatic effects
condition resistance to P. griseola, with the nature
of the gene depending on the pathogen race used.
- Identified QTLs for resistance to Thrips palmi.
The level of heritability and extent of genetic-by-environment
interaction were determined for insect damage and reproductive
adaptation under high infestation pressure.
- Progress made on developing a SCAR marker for resistance
to Apion godmani. Bulk segregant analysis and genetic
mapping of insect resistance narrowed down the number of
chromosomes containing genes for Apion resistance
and provided other potential molecular markers for use in
marker-assisted selection.
- Showed that inheritance of resistance to Pythium root
rot in MLB-49-89A, AND 1062, and RWR 719 was conditioned
by single dominant genes.
- Showed that the SCAR marker OPN02890C to ALS-resistant
genes in MEX 54 had limited application because it was not
useful in the populations used.
- The RAPD marker OPE04 was found useful for detecting a
resistant gene in MEX 54 in different backgrounds and, in
all cases, it segregated with the resistant dominant gene.
- Developed new lines incorporating insect resistance.
Developing Integrated Pest Management Components
- Common bean production returned to the Zapotitán
Valley, El Salvador, during the whitefly/geminivirus peak
season.
- Monitored the changing situation with whitefly species
and biotypes in target areas.
- Validated and refined action thresholds for managing the
whitefly Trialeurodes vaporariorum on snap beans
and dry beans.
- Monitored levels of resistance to insecticides in whitefly
populations in Colombia and Ecuador.
- A bioassay method to quantify inoculum of Fusarium
solani f. sp. phaseoli confirmed previous observations
that farmyard manure (FYM) increased both dry matter and
bean yield but also increased inoculum in the soil. Calliandra
green manure did not result in such high yields as FYM but
did not increase the pathogen's soil population.
- A dilution plating method was developed to quantify total
inoculum of Pythium species in the soil. The method
is limited, however, when focusing on specific (e.g. pathogenic)
species, as this requires colony identification.
- Neither FYM nor Calliandra green manure had significant
impact on Pythium populations. FYM increased soil
fertility and yield but stored up potential problems by
increasing pathogen numbers. Calliandra green manure may
therefore be preferred as a component of a series of management
practices to reduce the impact of root rots.
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Output 4: Strengthened Institutional,
Organizational, and Collaborative Capacity of NARS and Subregional
Networks in Africa and Latin America
Strengthen Capacity of NARS by Increasing the Knowledge
and Skills of Scientists and Staff from NARIs, NGOs, and Rural
Service Providers
- Provided individual training of national scientists.
- CIAT scientists participated in the planning activities
in Central America, the Andean Region and African networks.
- Four African scientists finished their MSc degrees.
- One scientist from SABRN participated in the participatory
plant breeding (PPB) monitoring tour in Honduras. This person
is expected to play a leading role in providing support
in participatory plant breeding within the SABRN.
- Two socioeconomics resource persons from Kenya and Uganda
have trained six national socioeconomists from D. R. Congo,
Ethiopia, Malawi, Rwanda, Tanzania, and Uganda.
- Held two PPB courses for participants from Kenya, Uganda,
Rwanda, and Tanzania.
- In February 2003, CIAT organized a short course on marker-assisted
selection in Uganda. Six SABRN participants who had access
to biotechnology laboratory facilities attended. They were
from Malawi, southern highlands of Tanzania, Zambia, and
the Republic of South Africa. Also attending were another
nine participants from the ECABREN region, that is, from
Ethiopia, Kenya, Rwanda, and Uganda.
- The first international course on "Bean Breeding,
Using Marker-Assisted Selection" was organized at CIAT
headquarters for Latin American scientists from the national
programs of Argentina, Bolivia, Colombia, Costa Rica, Ecuador,
El Salvador, Haiti, Mexico, Nicaragua, and Peru.
- Several training workshops were organized and implemented
for bean IPM farmer group representatives, district and
village extension officers, rural service providers, and
community local leaders at project sites in Kenya, Tanzania,
and Malawi.
- Former PPB farmer groups in northern Tanzania were linked
to IPM farmer groups through cross visits and farmer field
days.
- This year, senior scientists traveled more frequently
between Africa and headquarters. The pathologist and two
breeders traveled twice, and a breeder and pathologist traveled
from Africa to headquarters at mid-year, leading to closer
integration.
Strengthening International Collaboration through Networks
(intra- and inter-network collaboration) and/or Bilateral
Relations
- Identified ECABREN demand-driven regional research and
development portfolio. Consensus reached by stakeholders
on research priorities.
- Between August and September 2003, four Future Harvest
Centers (CIAT, CIMMYT, ICRISAT, and IITA), together with
the SSSN, organized two joint workshops to sensitize various
stakeholders on the sustainable ways of producing and distributing
seed of open-pollinated and self-pollinated crops. The workshops,
one for Zimbabwe and Botswana, and the other for Zambia
and Malawi, together pulled over 50 participants from various
organizations, including NGOs, CBOs, and farmers' associations,
to strengthen partnerships and collaboration.
- Plan International (Malawi), Malawi National Bean Research
Team, and CIAT-SABRN have formed a new partnership in which
CIAT and Malawi NARS will provide backup with bean-based
technologies and enabling Plan International to use rural
innovation expertise. Plan International is providing the
funds.
- The top six cultivars (CIM 9314-4, DC-95-96, GCI-SB-20RR,
ECAB0545, DC-12074-3-1 and CIM 9223-2) of 100 cultivars
from the Southern Africa Regional Bean Evaluation Nursery
(SARBEN) performed well at three or more sites out of eight
sites in the SADC region. The cultivars were selected for
further evaluation in partnership.
- The two top cultivars for yield across eight sites of
SARBEN in various SADC countries were DC-95-96 and PC-512-84.
Both are sugar beans, with medium-sized to large seeds,
cream to beige in color with red speckles. Sugar beans command
the biggest market share in the Republic of South Africa
and surrounding countries.
- The national bean research program in the southern highlands
of Tanzania, while evaluating and yield testing Andean bush
and climbing bean lines from CIAT, has identified appropriate
varieties for mid-altitude ecosystems to distribute to local
extension workers, agronomists, NGOs, and farmer-led research
committees (CIALs, Spanish acronym).
- Collaboration with CORPOICA and the universities and agricultural
colleges of the Departments of Nariño and Valle de
Cauca, Colombia, has led to extensive testing of bush and
climbing bean parental genotypes and potential varieties.
- Collaboration with the national bean programs of Bolivia,
Ecuador, and Peru has led to testing of CIAT germplasm from
various seed classes.
- Breeding lines multiplied to increase seed of commercial
grain types for the Andean Region.
- A large number of nurseries and germplasm materials were
distributed to bean network partners.
- HarvestPlus (formerly the Biofortification Challenge Program)
is becoming a bridge for international collaboration between
Latin America and Africa and is drawing actors that, traditionally,
have not been involved in agricultural research nor in the
diffusion of improved germplasm.
Collaborative Projects Developed and Executed with NARS
and Regional Networks
Relationships with Brazil are being revived through three
different Challenge Programs.- International collaboration between Mexico, Cuba, and,
possibly, Bolivia on symbiotic nitrogen fixation is consolidating
around a population of recombinant inbred lines derived
from the cross BAT 477 × DOR364.
- Drought is emerging as a theme that brings together bean
researchers, especially in Central America. Researchers
in Brazil and Africa, and in NRM are showing interest.
- The VICARIBE (Caribbean International Bean Trial) was
officially launched.
- A project on drought tolerance breeding was initiated
in Nicaragua. It is expected to open up new opportunities
for regional collaboration.
- The Tropical Whitefly IPM Project helped finance the evaluation
and subsequent release of the new BGYMV-resistant cultivar
CENTA San Andrés in Central America.
- Prepared joint collaboration and concept notes.
Socioeconomic Activities
- The improved variety K132 (CAL 96) has been adopted at
a level of 48% in eastern Uganda, resulting in a doubling
of bean income in 8 years.
- FAO policy on seed aid is being modified significantly
as a result of research by a CIAT social scientist.
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