Genetic variation in the endangered Inner Mongolia endemic shrub Tetraena mongolica Maxim. (Zygophyllaceae) Original Research Article

Tetraena mongolica Maxim, is a critically endangered and endemic species of westem Inner Mongolia in China. Genetic variability within and among eight extant populations of this species was assessed using ISSR PCR (13 primers). We expected a low genetic diversity level, but our results revealed an intermediate level of intraspecific genetic diversity, probably resulting from this species being in a refuge during the last glaciation (at population level: P=48.1%, Ae=1.305, HE=0.177 and Hpop=0.264; at species level: P=63.3%, A=1.368, HT=0.213 and Hsp=0.324). A low level of genetic differentiation among populations was detected based on Neiʹs genetic diversity analysis (16.91%), Shannonʹs diversity index (18.83%) and AMOVA (15.2%). Populations shared high levels of genetic identity (I=0.9516±0.013). The extensive gene flow was a plausible reason for the low genetic differentiation.