A segregation distortion locus located on linkage group 4 of the chickpea genetic map

A chickpea F-2 population of 593 plants derived from the intraspecific cross ILC3279 x WR315 was genotyped for markers closely linked to quantitative trait loci (QTLs) for ascochyta blight resistance (QTL(AR1) and QTL(AR2) located on linkage group 4 and QTL(AR3) on linkage group 2). All the markers located on linkage group 4 exhibited strongly distorted segregation with respect to the expected Mendelian inheritance, towards the male parental line. This skewed segregation was also observed in a second F-2 population of 50 plants derived from the same cross, confirming the presence of a region of distorted segregation on this linkage group and its heritability. The most skewed markers were SC-Y17 and TA72, which were tightly linked to each other, indicating that they may both be closely associated with the genetic factor responsible for segregation distortion in chickpea. To attempt to explain the non-Mendelian segregation, by identifying factors to which it could be attributed, three different chi-square tests were carried out to test different hypotheses using the data obtained from examining co-dominant markers associated with segregation distortion. According to our results, the distorted segregation could be caused by gametophytic factors that affect either male or female gametes. Pollen fertility and meiosis were also analysed to determine their relationship with segregation distortion; however, these not seem to be inducing factors in the non-Mendelian segregation reported in this study.