Pj. Balintkurti et al., RFLP LINKAGE ANALYSIS OF THE CF-4 AND CF-9 GENES FOR RESISTANCE TO CLADOSPORIUM-FULVUM IN TOMATO, Theoretical and Applied Genetics, 88(6-7), 1994, pp. 691-700
Four different populations segregating for one of the two closely link
ed (possibly allelic) tomato disease resistance genes to the fungus Cl
adosporium fulvum, Cf-4 and Cf-9, were generated and analysed for reco
mbination frequencies between the Cf-genes and restriction fragment le
ngth polymorphism (RFLP) loci. The population consisting of F-2 progen
y from the interspecific cross Lycopersicon esculentum carrying Cf-9 x
L. pennellii was identified as the most useful for RFLP mapping of th
e Cf-4/9 locus and an RFLP map around this locus was constructed mainl
y using this population. The two closest markers identified were CP46,
2.6 cM distal, and a group of 11 markers including TG236, 3.7 cM prox
imal to Cf-4/9. A polymerase chain reaction (PCR)-based procedure for
the rapid identification of recombination events between these two mar
kers was developed. The regions of foreign DNA introgression surroundi
ng Cf-4 and Cf-9 in near-isogenic lines were delimited.