Microsporogenesis in the triploid hybrid 'Beilinxiongzhu 1#' and detection of primary trisomy in 2x × 3 × Populus hybrids.

Background: Primary trisomy is a powerful genetic tool in plants. However, trisomy has not been detected in Populus as a model system for tree and woody perennial plant biology.

Results: In the present study, a backcross between Populus alba × Populus glandulosa 'YXY 7#' (2n = 2x = 38) and the triploid hybrid 'Beilinxiongzhu 1#' (2n = 3x = 57) based on the observation of microsporogenesis and an evaluation of the variations in pollen was conducted to create primary trisomy.

Gibberellins as a novel mutagen for inducing 2n gametes in plants.

The plant hormone gibberellin (GA) regulates many physiological processes, such as cell differentiation, cell elongation, seed germination, and the response to abiotic stress. Here, we found that injecting male flower buds with exogenous gibberellic acid (GA) caused defects in meiotic cytokinesis by interfering with radial microtubule array formation resulting in meiotic restitution and 2n pollen production in . A protocol for inducing 2n pollen in with GA was established by investigating the effects of the dominant meiotic stage, GA concentration, and injection time.

Heat shock-induced failure of meiosis I to meiosis II transition leads to 2n pollen formation in a woody plant.

The formation of diploid gametes through chromosome doubling is a major mechanism of polyploidization, diversification, and speciation in plants. Unfavorable climate conditions can induce or stimulate the production of diploid gametes during meiosis. Here, we demonstrated that heat shock stress (38°C for 3 or 6 h) induced 2n pollen formation, and we generated 42 triploids derived from heat shock-induced 2n pollen of Populus canescens.

In vitro octaploid induction of Populus hopeiensis with colchicine.

Background: Autopolyploids, especially artificial lines, provide model systems for understanding the mechanisms of gene dosage effects on trait variation owing to their relatively uniform genetic background. Here, a protocol for in vitro octaploid induction of Populus hopeiensis from leaf blades with colchicine treatment was established through investigation of the effects of different pre-culture durations, colchicine concentrations, and exposure times.

Results: We found that pre-culture duration, colchicine concentration, and exposure time had significant effects on the survival rate, shoot regeneration rate, and octaploid induction rate of P.