Systematic position of Polygonatum simizui (Convallariaceae) based on morphological, cytological and chloroplast DNA sequence data

Polygonatum simizui has been treated as a synonym of P. odoratum s.L , but can be distinguished from P. odoratum by having a terete stem, more leaves on each individual, and relatively small flowers. The results of morphological study showed that there exist some regular and correlated variations in plants of P. odoratum s.L , and some of them can be identified as P. simizui based on the main key characteristics. The results obtained from this study indicate that the morphological differences in plants of P. odoratum s.L are paralleled by some cytological and molecular characteristics. Four NOR loci are observed in the chromosomes of plants that can be identified as P. simizui by in situ hybridization with the 18S-5.8S-26S rDNA probes. The basic number of chromosome of them is n = 9 , which is very different from that of the other plants of P. odoratum s.L The same variation patterns are found in PCR-RFLP analysis of trnK and rpllG genes. As it seems to be unreasonable to include all these plants in a single species, P. simizui should be considered to be a distinct species.