Genetic diversity of Ulmus lamellosa by morphological traits and sequence-related amplified polymorphism (SRAP) markers

• The genetic diversity and differentiation of Ulmus lamellosa were evaluated using morphological traits and SRAP markers.
• There exists significant differences in 14 morphological traits.
• We examine the rich genetic diversity in 16 U. lamellosa populations based on SRAP markers.
• To understand the genetic diversity of U. lamellosa will provide useful information for its protection.

Ulmus lamellosa is an endangered and endemic species mainly distributed in North China. Understanding the genetic diversity of this species is useful to design the suitable conservation planning. In this study, the genetic diversity of 16 natural populations of U. lamellosa was evaluated by morphological traits and sequence-related amplified polymorphism (SRAP) markers. The morphological data showed that significant difference was found among 14 morphological traits. Coefficient of variation (CV) and phenotypic differentiation coefficient (VST) were 27.2% and 27.3% respectively. Based on SRAP markers, the percentage of polymorphic bands (PPB) of U. lamellosa populations was 82.7%. Nei's gene diversity (He) and Shannon's information index (I) were 0.22 and 0.36 respectively. High genetic differentiation was detected within populations (P < 0.050) and less genetic differentiation (GST = 0.3696) among populations by AMOVA analysis. Sixteen populations of U. lamellosa were gathered into three distinct clusters based on morphological and molecular data, which consistent with the result of PCoA and STRUCTURE analysis. Mantel test revealed a significant correlation between genetic and geographic distances (r2 = 0.1238, P < 0.050). Both molecular and morphological data indicated that U. lamellosa was high in genetic diversity, which was probably due to the biological characteristics, distribution and modes of reproduction.