Generation and characterization of a tetraploid Populus davidiana

Tetraploid plants always exhibit noticeable changes in tissue structure and stress tolerance, but the underlying physiological mechanisms remain poorly understood. Here, we generated a tetraploid plant of Populus davidiana using colchicine induction and performed phenotypic characterization. The results showed that the tetraploid plant had bigger ground diameters and leaf area than the diploid plant. The tetraploid plant had thicker palisade tissue but less stomatal density than the diploid plant. The tetraploid plant also had higher chlorophyll content, net photosynthetic rate, maximal efficiency of PSII photochemistry, the effective quantum yield of PSII, photochemical quenching coefficient but lower non-photochemical quenching coefficient than the diploid plant. Furthermore, we found that the tetraploid plant displayed significantly enhanced drought and salt tolerance in comparison with the diploid progenitor. Our results not only revealed the structural and physiological changes in the tetraploid plant, but also provided a reference for the generation of better quality varieties. Key message In this study, a tetraploid poplar was obtained and phenotypic analysis revealed the structural and physiological changes of tetraploid poplar compared with its diploid ancestor.