Developing and Delivering Common Bean (Phasolus Vulgaris) Germplasm with Resistance to the Major Soil Borne Pathogens in East Africa
Sugarbeet and Bean Research
Project Number: 5050-21430-010-04
Start Date: Jan 01, 2013
End Date: Aug 31, 2016
Overall hypothesis or goal: We plan to utilize the latest tools in pathology, genetics, and genomics to characterize the variability of soil borne pathogens and to identify genetic resistance in a broad array of bean backgrounds and to transfer that resistance in a range of bean seed and growth types suitable for production and consumption in East Africa.
Specific objectives: With an overall goal of developing and delivering root rot management technologies (including common bean genotypes with resistance to major soil borne pathogens), our efforts will specifically focus on: 1: Identification and characterization of soil borne pathogens collected from field sites in Uganda and Rwanda; 2: Development of pathogen specific, high throughput phenotypic screening methods to characterize root rot resistance in Phaseolus sources; 3: Identify sources of resistance to Fusarium, Pythium, Sclerotium and Rhizoctonia in populations derived from interspecific crosses; 4: Genetic characterization of resistant genotypes by QTLs mapping and development of molecular markers for use in breeding programs; 5: Identification of genomic regions and candidate genes responsible for resistance through transcriptome analysis of resistant and susceptible bean genotypes; and 6: Delivery of improved integrated root rot management technologies to farmers, outreach in the form of tutorials, identification keys, and protocols in the form of flat-text, slide share, and video to be shared with bean research community mainly in East Africa, developed through the Plant Breeding and Genomics Community of Practice (PBG), ipmPIPE and delivered through eXtension.org.
Conduct the genetic and phenotypic characterization of pathogen isolates collected in bean producing regions of Uganda and Rwanda to examine the population diversity of major pathogenic forms, and identify specific isolates for screening breeding populations derived from interspecific crosses between P. vulgaris x coccineus, P. acutifolius, and P. dumosus under controlled conditions at CIAT; Promising materials would be tested under field conditions in natural hot spots in Uganda and Rwanda; RNA seq. of root and hypocotyl tissue of resistant and susceptible genotypes inoculated with individual and multiple pathogens would be conducted in combination with QTL studies on recombinant inbred line populations to identify genomic regions contributing to resistance. The wider impact strategy of the CIAT/Pan-Africa Bean Research Alliance (PABRA) will also be used to deliver integrated root rot management options to farmers in Rwanda and Uganda.