|Fourie, D - ARC, SOUTH AFRICA|
Submitted to: Plant Breeding Symposium South African Plant Breeder's Association
Publication Type: Abstract Only
Publication Acceptance Date: February 14, 2006
Publication Date: March 13, 2006
Citation: Miklas, P.N., Fourie, D. 2006. Halo blight resistance in host differential cultivar ZAA 12 is conditioned by three genes. 6th Plant Breeding Symposium, Western Cape, South Africa, March 13-16, 2006, p. 3. Technical Abstract: Halo bacterial blight caused by Pseudomonas syringae pv. phaseolica (Psp) is a serious seed-borne disease limiting common bean production worldwide. Genetic resistance provides the most effective means for combating this disease. ZAA 12 (A43) is the most resistant host differential cultivar conditioning resistance to 7 of 9 differential races of the pathogen. Our objective was to study the inheritance of halo blight resistance in ZAA 12. A recombinant inbred population consisting of 79 RILS was developed from the cross ZAA 12/Canadian Wonder. ZAA 12 is resistant to Psp Races 2, 3, 4, 5, 7, 8, and 9. Canadian Wonder is a universal susceptible. Separate greenhouse inoculations of the RILs and parents were performed for each race. ZAA 12 has three major gene loci: Pse-2, Pse-3, and Pse-4. Results indicate that Pse-2 confers resistance to Races 2, 3, 4, 5, 7, 8, and 9. Pse-3 conditions resistance to Races 3 and 4. Pse-4 conditions resistance to Race 5. Preliminary results for the inheritance of halo blight resistance in ZAA 12 (A43) support the findings of Teverson (1991) that: i) two independent dominant genes Pse-3 and Pse-2 condition resistance to Races 3 and 4, and ii) two independent dominant genes Pse-4 and Pse-2 condition resistance to Race 5. A new finding from this study is that a single gene Pse-2 (or gene cluster) conditions resistance to Races 2, 7, 8, and 9.