Genetic maps of RAPD, AFLP and ISSR markers in Ananas bracteatus and A-comosus using the pseudo-testcross strategy

Genetic maps of random amplified polymorphic DNA (RAPD), amplified fragment length polymorphisms (AFLP) and inter simple sequence repeats (ISSR) markers in pineapple (2n = 2x = 50) are reported for the first time. On the basis of a segregating population of 46 F1 individuals from a cross Ananas comosus x A. bracteatus, genetic maps of these two species were constructed using the two-way pseudo-testcross approach. The A. bracteatus map consists of 335 markers (60 RAPDs, 264 AFLPs and 11 ISSRs) assembled into 50 linkage groups, 26 of them with at least four markers. The A. comosus map consists of 157 markers (33 RAPDs, 115 AFLPs, eight ISSRs and the 'piping' trait locus) organized into 30 linkage groups, 18 of them with at least four markers. These maps cover, respectively, 57.2% of the A. bracteatus genome estimated as 3693 cM long, and 31.6% of the A. comosus genome calculated as 4146 cM. A rough estimate of 120 and 127 kbp/cM on average was found for the relationship between physical and genetic distance for A. bracteatus and A. comosus, respectively.