IDENTIFICATION OF RAPD MARKERS LINKED TO COMMON BACTERIAL-BLIGHT RESISTANCE GENES IN PHASEOLUS-VULGARIS L

Seven hundred and fifty-six random primers were screened with bulks of genomic DNA from common bacterial blight (CBB) resistant and suscepti ble bean plants. The plants were from a breeding population derived fr om an interspecific cross between Phaseolus acutifolius and Phaseolus vulgaris. Four RAPD markers, named R7313, RE416, RE49, and R4865, were found to be significantly associated with CBB resistance in this popu lation. Forty-nine molecular markers segregating in the population wer e clustered into 8 linkage groups by a MAPMAKER linkage analysis. The largest linkage group was 140 cM long and contained 25 marker loci, in cluding marker R4865. Markers R7313, RE416, and RE49 were clustered on another linkage group. A regression analysis indicated that the marke rs in these two groups together accounted for 81% of the variation in CBB resistance in the population. The addition of another marker, M568 10, which was not individually associated with CBB resistance, increas ed the total contribution to the trait to 87%.