Phylogenetic signals, biomass allocation, and variation patterns collectively reflect the adaptive strategies of root system architecture of annual ephemerals

Root system architecture is limited by phylogenetic relationships and ultimately affect the biomass allocation of resource acquisition organs. However, many studies have only focused on the impact of environmental driven trait variation and biomass allocation on root system architecture, neglecting the impact of phylogenetic relationships. Therefore, biomass allocation and phylogenetic relationship affect the root system architecture and its variation patterns were investigated in annual ephemerals. We found that the interspecific variation of root tissue density (RTD) was the highest (51.63%), and the topological index (TI) was the lowest (5.92%). Moreover, the range of intraspecific variation for specific root length (SRL) and specific surface area (SRA) is high, and the TI is low. This convergence and divergence of root traits reflect the Phenotypic plasticity of roots and their adaptation to environmental filtering and interspecific competition. Maximum root depth (MRD) was detected significantly and weakly phylogenetic signal (0