The use of Rapd markers for lentil genetic mapping and the evaluation of distorted F2 segregation

To maximize the extent of polymorphism within a mapping population wide crosses are often made, frequently resulting in distorted segregation. Two parents used in the crosses in this study contained ca 50% from wild lentil genome (Lens culinaris subsp. Orientalis). We investigated the use of random amplified polymorphic DNA (RAPD) in the lentil (Lens culinaris Medik), for genetic mapping and testing for segregation distortion in F-2 populations. In cross 1, 83% of the RAPD markers showed segregation distortion, which was also observed for isozyme and morphological loci. By contrast, in cross 2, there was little (10%) segregation distortion. Out of 390 primers tested, 116 primers (29.7%) yielded 192 polymorphic fragments between parents of cross 2. This polymorphism was confirmed as reproducible. Seventy-eight segregating loci were analyzed for linkage, at a LOD score > 3.0, resulted in 28 RAPD, one RFLP, one morphological and three oligonucleotide markers, which were assigned to 9 linkage groups spanning 206 cM. Clearly, in lentil RAPD markers were valuable for genetic mapping and evaluation of segregation distortion.