Spatial and Temporal Variation of Precipitation Drives the Genome Size Variation in in Chinese Mainland.

Genome size is an adaptive trait, and its variations influence the organismal phenotype and fitness. In this study, we propose a hypothesis linking variations in genome size within to ecological factors. To test this hypothesis, we employed flow cytometry to estimate genome size in seven species from Chinese mainland. Subsequently, we reconstructed the phylogenetic relationship of these species using the cytochrome oxidase subunit 1 gene and conducted phylogenetic comparative analysis to assess the relationships between genome size and niche breadth or 19 bioclimatic variables. Our findings indicate the following: (1) genome size in can be categorized into three groups, similar to the phylogenetic clades; (2) there is a negative correlation between genome size in species and the precipitation niche breadth of species; (3) the estimated divergence time of dates back 153 Mya, during the Jurassic period. We assume that consistent aridity geological periods may promote the evolution of species with a large genome size, whereas rapidly fluctuating humidity geological periods may have the opposite effect.