Linkage map of Japanese black pine based on AFLP and RAPD markers including markers linked to resistance against the pine needle gall midge

Macrogametophytes derived from the seeds of a tree resistant to pine needle gall midge (PGM) were analyzed using amplified fragment length polymorphis m (AFLP). A total of 244 segregating loci were detected among 71 macrogamet ophytes. Combining the AFLP results with previously reported segregation da ta for 127 random amplified polymorphic DNA (RAPD) markers, 157 AFLP and 50 RAPD markers with confirmed map positions were assigned to 20 linkage grou ps and three pairs covering 2085.5 cM with an average distance of 10.1 cM. The total map distance covers about 77.1-78.4% of the total genome, estimat ed to be approximately 2665-2719 cM in length. Thus, using AFLP markers, th e previous RAPD map of this tree was improved in terms of the average dista nce between markers, the total map distance, and coverage of the genome. Th ree RAPD markers linked to a gene associated with resistance to PGM were al so located on this map.