Discrimination among species of Papaver based on the plastid rpl16 gene and the rpl16-rpl14 spacer sequence.

An attempt was made to discriminate among six species of Papaver (P. bracteatum, P. orientale, P. pseudo-orientale, P. rhoeas, P. setigerum and P. somniferum) by comparing the nucleotide sequences of the plastid rpl16 gene and the rpl16-rpl14 spacer region. Comparison of sequences allowed us to distinguish five species, namely P. bracteatum, P. orientale, P. pseudo-orientale, P. rhoeas and P. setigerum plus P. somniferum from one another, but sequences from P. setigerum and P. somniferum were identical. It is difficult to distinguish between P. bracteatum, P. orientale and P. pseudo-orientale at the vegetative stage of growth. However, our method allowed us to distinguish between these three species and the others using nucleotide sequences and should allow identification of P. bracteatum that has been cultivated illegally in the garden in Japan. Furthermore, P. rhoeas was clearly discriminated from P. setigerum and P. somniferum by reference to the sequence of the rpl16 exon using young seedlings.