Affiliation:
1. Beijing Forestry University
2. Inner Mongolia Academy of Forestry
Abstract
Abstract
Background Artificial induction of polyploidy is the most common and effective way to improve the biological properties of Populus and develop new varieties of this tree. Here, a protocol using colchicine and based on an efficient shoot regeneration system using leaf blades was established for inducing tetraploidy in vitro from diploid Populus hopeiensis. The traits that were evaluated for each ploidy level were stomatal characteristics, leaf blade size, and growth.Results We found that genotype, preculture duration, colchicine concentration, and colchicine exposure time had highly significant effects on the tetraploid induction rate. The optimal protocol for inducing tetraploidy in P. hopeiensis was to preculture leaf blades for 7 days and then treat them for 4 days with 40 mg/L colchicine. The tetraploid induction rates of genotypes BT1, BT3, and BT8 were 21.2, 11.4 and 16.7%, respectively. A total of 136 tetraploids were identified by flow cytometry analysis and somatic chromosome counting. The stomatal length, width, and density of leaf blades significantly differed between diploid and tetraploid plants. Compared with their diploid counterparts, the tetraploids produced larger leaf blades and had a slower growth rate. Our findings document the modified morphological characteristics of P. hopeiensis following whole-genome duplication (e.g., induced tetraploidy).Conclusions We established a protocol for in vitro induction of tetraploidy from diploid P. hopeiensis leaf blades treated with colchicine.
Publisher
Research Square Platform LLC