title: Induction of 2n female gametes in Populus adenopoda Maxim by high temperature exposure during female gametophyte development.
abstract: In order to produce triploid plants, 2n female gametes were induced by treating female buds and developing embryo sacs of Populus adenopoda Maxim with high temperature exposure. During megasporogenesis, tests were conducted on the relationship between female gametophyte development and morphological changes of female catkins. In the resulting progeny, 12 triploids were produced, and the highest rate of triploid production was 40%. Cytological observation revealed that the pachytene to diakinesis phase of meiotic stages may be a suitable period for inducing megaspore chromosome doubling through high temperature exposure. On the other hand, catkins of 6-72 h after pollination were treated for inducing embryo sac chromosome doubling. In the offspring seedlings, 51 triploids were detected and the highest efficiency of triploid production was 83.33%. Correlation analysis between the proportion of each embryo sac's developmental stage and the percentage of triploid production indicated that the second mitotic division may be the most effective stage for 2n female gamete induction. Our findings showed that high temperature exposure is an ideal method for 2n female gamete induction. Heterozygous offspring are valuable for breeding programs of P. adenopoda.
authors: National Engineering Laboratory for Tree Breeding, Beijing Forestry University , Beijing 100083, P. R. China ; Key Laboratory for Genetics and Breeding of Forest Trees and Ornamental Plants, Ministry of Education, College of Biological Sciences and Biotechnology, Beijing Forestry University , Beijing 100083, P. R. China.
authors: Min
authors: M
authors: Lu
authors: Pingdong
authors: P
authors: Zhang
authors: Xiangyang
authors: X
authors: Kang
keywords: 2n female gamete; Populus adenopoda; embryo sac; high temperature; megasporogenesis; triploid breeding
references: Proc Natl Acad Sci U S A. 1932 Mar;18(3):222-9
references: 16587665
references: Science. 1983 Jun 3;220(4601):1049-51
references: 17754551
references: Theor Appl Genet. 1977 Mar;49(2):53-61
references: 24408580
references: New Phytol. 1995 Jan;129(1):1-22
references: 33874422