Genetic mapping of linkage group XIX and identification of sex-linked SSR markers in a Populus tremula × Populus tremuloides cross

A progeny of 130 Fl individuals of an interspecific cross between Populus tremula L. and Populus tremuloides Michx. was used for genetic mapping of linkage group XIX with SSR markers based on the Populus trichocarpa Torr. & A. Gray genome sequence. Several fully sex-linked SSR markers were identified and mapped to a central position on the male P. tremuloides map of linkage group XIX. For the SSR markers tested here, the position on the assembled P. tricho- carpa genome sequence is known, allowing sex-linked markers to be assigned to the central region of scaffold/chromo- some 19 of P. trichocarpa. The sex linkage of the SSR markers was validated in other P. tremula x P. tremuloides crosses and also tested in Populus alba L. and Populus nigra L.