Variations in morphological traits of bermudagrass and relationship with soil and climate along latitudinal gradients

Background: This complex environmental heterogeneity coupled with the long-standing history offers scenario suitable for and favoring the evolution and existence of variation of morphological traits. Methods: In this study, we measured 10 morphological traits of 310 Cynodon dactylon individuals sampled at 16 different locations along latitudinal gradients between 22 degrees 35'N and 36 degrees 18'N to reveal phenotypic plasticity influenced by latitude. In addition, the relationships between morphological variation and soil nutrient and climate factors were analyzed. Results: Analysis of variance, divesity examination and Mantel correlation test detected a significant effect of latitude on morphological traits. Cluster analysis and principal component analysis clearly separated the selected populations into four groups according to latitude. Larger morphological sizes of C. dactylon appeared at the low- and high-latitude regions. Correlation analysis indicated that high morphological variations were significantly correlated with climate factors and soil nutrient. Conclusion: This study suggests morphological variation of wild bermudagrass is greatly influenced by latitude as well as soil and climate, which could be useful resources for genetic studies and evolution.