Using SSR markers to study the mechanism of 2n pollen formation in Populus x euramericana (Dode) Guinier and P. x popularis

摘要

Using cytological methods and SSR DNA marker analysis, this study revealed the formation mechanisms and the genetic constitutions of the 2n pollen in Populus x euramericana (Dode) Guinier and P x popularis.In P. x euramericana (Dode) Guinier, four abnormalities in micro sporogenesis were observed: parallel spindle, fused spindle, tripolar spindle and premature cytokinesis. The first three can lead to first-division restitution (FDR) 2n pollen formation and the last one can form second-division restitution (SDR) 2n pollen. The SSR marker analysis results of parents and their tetraploidy filial generation confirmed that the genetic constitution of 2n pollcn produced by P x euramericana (Dode) Guinier was FDR.In P. x popularis, three of these abnormalities were observed: parallel spindle, fused spindle and premature cytokinesis. The SSR marker analysis results showed the genetic constitution of 2n pollcn produced by P. x popularis was SDR. Natural 2n female gametes in P x euramericana (Dode) Guinier arc reported for the first time. SSR analysis indicated that natural 2n female gametes of P x euramericana (Dode) Guinier did exist and were fertile, which could be FDR genetic constitution.The results from this study showed a great potential for using 2n gametes to produce polyploid poplar clones, which can be used effectively for polyploid breeding for poplar species in the section Aigeiros.