Genetic diversity and taxonomic status of Pinus tabulaeformis f. shekanensis revealed by ISSR markers.

Pinus tabulaeformis f. shekanensis is a rare taxon endemic in the Ziwuling Loess Plateau, of which only one population is known. Inter-simple sequence repeat molecular markers were employed to compare the taxon's genetic diversity with its 4 nearest wild relatives (P. tabulaeformis, P. tabulaeformis var. mukdensis, P. massoniana, and P. henryi) to assess the taxonomic status of P. tabulaeformis f. shekanensis. Inter-simple sequence repeat marker data revealed higher genetic diversity in the P. tabulaeformis f. shekanensis population than in the other populations. Population genetic analysis (neighbor-joining cluster analysis, principal coordinate analysis, and structure clustering) revealed that P. tabulaeformis f. shekanensis and P. tabulaeformis are likely conspecific (the former may be a variety of the latter). Strategies are also proposed for the conservation of P. tabulaeformis f. shekanensis.