Development of sex-associated RAPD markers in wild Pistacia species

Marker assisted selection may greatly facilitate pistachio rootstock breedi ng as well as cultivar improvement, because of the long juvenile period of Pistacia species. Early diagnosis of seedling sex type would assist breedin g and nursery-management in these dioecious species. We searched for RAPD m arkers linked to sex in P. atlantica, P. terebinthus and P. eurycarpa, the main wild species in Turkey that are used as rootstocks for P. vera. For th is purpose, leaf samples were collected from male and female individual tre es from each species and sex-pooled DNA samples were prepared by mixing the DNA of ten male and ten female individuals, to screen for sex associated R APD bands. A total of 472 primers have been screened so far and two bands, amplified by primers BC156 and BC360, appeared to be sex assocaited in P. e urycarpa. The bands were tested in 30 male and 37 female individuals. Band BC156((1300)) was present in all, except one, female trees and was absent f rom all the male trees. Band BC360((500)) was amplified in 31 out of 37 fem ales and was absent from all the males. In P. atlantica, one primer, OPAK09 , amplified a female-associated band (850 bp), that was present in ah 46 fe male individuals tested and absent in all the 38 male trees tested. it is l ikely that these markers are linked to sex-determining loci. The sex determ ination mechanism has not been characterized in Pistacia and segregating po pulations from controlled crosses are required to elucidate such mechanism and also to measure the genetic distance of our markers from the putative s ex loci.