Upload
lucas-newton
View
217
Download
0
Embed Size (px)
Citation preview
Bean/Cowpea CRSP
Biodiversity and
Conservation Activities
James R. Steadman- University of Nebraska
MalawiMozambiqueSouth Africa
Tanzania
Costa RicaDominican RepublicEcuadorEl Salvador
GuatemalaHaiti
HondurasJamaica
Nicaragua
Latin America
and Caribbean
Project
BeninBurkina FasoCameroonGhana
NigerNigeriaSenegal
Zimbabwe
West Africa Project
East and Southern
Africa Project
•Development of improved germplasm and cultivars for common bean and cowpea. Biotic stresses emphasized
Bean/Cowpea CRSP priority over past 25 years
Collection Area No. Accessions Location of Storage
Argentina/Bolivia 112 USDA-PI/ Salta, Argentina
Honduras 111 USDA-PI / Zamorano
Honduras landraces 452 Zamorano
Tanzania landraces 80 USDA-PI
Caribbean 65 Haiti/Puerto Rico/ DR
Domincan Republic 28 USDA-PI / IDIAF (DR)
Total 848
Accessions of Common Bean and Related Species
Accessions of Cowpea Germplasm
Cowpea collections from Africa increased USDA-PI holdings from 2,000 to 7,000 in 20 years
USA elite breeding lines crossed to landraces from Africa and the Americas
•In 1980’s USA beans had narrow germplasm base
•Crosses broaden genetic diversity and
•Increase resistance to biotic stresses.
Use of exotic bean germplasm by Bean/Cowpea CRSP researchers
• A unique source of resistance to Bean Golden Yellow Mosaic derived from P. coccineus (Univ. of Puerto Rico)
• Wild tepary bean germplasm is a source of resistance to bean weevil (Oregon State Univ.)
• High-yielding common bean breeding lines developed from a cross with a wild bean accession (Michigan State Univ.)
• Dominican PC-50 used for white mold and adult plant rust resistance (Univ. of Nebraska)
Biodiversity of Bean Lines in the Caribbean
• Dominican landraces were characterized and used to improve bean production
• Haitian bean germplasm may be a source of unique combinations of Andean and Mesoamerican genes for disease resistance.
Overlooked area of biodiversity-Plant associated microbes
Pathogen Location Number/races/isolates
Uromyces appendiculatus
UN-L, USDA 550
Rhizoctonia solani UN-L, Cornell >200
Colletotrichum lindemuthianum
Zamorano, CIAT, MSU
>100
Phaeoisariopsis griseola
Zamorano, UC-Davis, CIAT
>100
Domestic & international culture collection of bean pathogens- Fungal
Pathogen Location Number/races/strains
Xanthomonas campestris pv. phaseoli
UN-L, UC-Davis, CIAT
>300
Pseudomonas syringae
UN-L, U-Wisconsin 480
Pseudomonas syringae pv. phaseolicola
UN-L, CABI >200
Domestic & international culture collection of bean pathogens- Bacterial
Virus Location Number/strains
Bean Golden Mosaic U-WI,
U-AZ, CIAT, Brazil
>100
Bean Golden Yellow Mosaic
U-WI,
U-AZ, CIAT
>200
Bean Common Mosaic
USDA, CIAT 50
Domestic & international culture collection of bean pathogens- Viruses
Location Number/strains
Rhizobium spp.
Other species
U-MN, USDA, CIAT, Australia
>300
Domestic & international culture collection of bean pathogens- BNF Microbes
In addition to new sources of disease resistance and screening methods-
Bean & Cowpea germplasm and pathogen collections
•Unique coevolution of host/pathogen studies- bean rust, web blight
•Transgenic cowpea/insectstudies- pest population diversity
•Farmer association/NAR collaboration- (Dom. Republic)
•Local committees of agricultural research (Ecuador)
•Farmer-managed field trials (Malawi)
•Participatory breeding (Central America)
Deployment of improved bean lines
•Dambos (wetlands) used for seed production in Malawi with minimal impact on natural diversity
On-going need for clean seed of new lines
Present and Future conservation/diversity problems
•Inadequate microbiology conservation locations, e.g. ATCC
•Homeland security / APHIS requires permit for all pathogens/pests
•Underfunding for germplasm collection andconservation
•Developing country fears of losing natural resources- limited or no collections
•Loss of landraces/ wild germplasm
•Loss of funding for CRSPs and IARCs
Present and Future conservation/diversity problems