Integration of new CAPS and dCAPS-RGA markers into a composite chickpea genetic map and their association with disease resistance

A composite linkage map was constructed based on two interspecific recombinant inbred line populations derived from crosses between Cicer arietinum (ILC72 and ICCL81001) and Cicer reticulatum (Cr5-10 or Cr5-9). These mapping populations segregate for resistance to ascochyta blight (caused by Ascochyta rabiei), fusarium wilt (caused by Fusarium oxysporum f. sp. ciceris) and rust (caused by Uromyces ciceris-arietini). The presence of single nucleotide polymorphisms in ten resistance gene analogs (RGAs) previously isolated and characterized was exploited. Six out of the ten RGAs were novel sequences. In addition, classes RGA05, RGA06, RGA07, RGA08, RGA09 and RGA10 were considerate putatively functional since they matched with several legume expressed sequences tags (ESTs) obtained under infection conditions. Seven RGA PCR-based markers (5 CAPS and 2 dCAPS) were developed and successfully genotyped in the two progenies. Six of them have been mapped in different linkage groups where major quantitative trait loci conferring resistance to ascochyta blight and fusarium wilt have been reported. Genomic locations of RGAs were compared with those of known Cicer R-genes and previously mapped RGAs. Association was detected between RGA05 and genes controlling resistance to fusarium wilt caused by races 0 and 5.