Genetic analyses of the endangered medicinal plant Podophyllum emodi

The medicinal use of Podophyllum emodi Wall (Himalayan Mayapple; family: Berberideceae), a high-altitude plant species native to the alpine and sub alpine areas of Himalayas, dates back to ancient times [1]. The plant has been used in traditional Chinese System of Medicine for treatment of a number of ailments. To determine the population structure and outcrossing rate across the range of the species, we conducted AFLP analysis using four primer combinations for 31 populations. The genetic diversity of this species was high based on the level of polymorphic loci (155 of 197 loci; 92.31%) and Nei's gene diversity (ranging from 0.14532 to 0.2435; overall 0.2446). There was significant population genetic differentiation (G(ST)=0.287; circle minus (II)=0.221 from the Bayesian f=0 model). Results from the AMOVA analysis suggest that a majority of the genetic variance is attributed to variation within populations (69.43%), which is also evident from the PCoA. An estimate of the outcrossing rate based on genotypes of progenies from seven of the 31 populations using the multilocus method from the program MLTR ranged from 0.695 to 0.903, suggesting that the species is predominantly outcrossing. These results are encouraging for conservation, signifying that populations may persist due to continued genetic exchange sustained by the outcrossing mating system of the species.

Acknowledgements: This research was supported by the Natural Science Foundation of China (NSFC 30770153).

References: 1. Chawla R et al. (2005) Mol Cell Biochem 273: 193–208.