Journal ArticleDOI
Occurrence and mechanisms of 2n egg formation in 2x potato
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TLDR
Five mechanisms of 2n egg formation were identified: synaptic variant (genetically first division restitution), delayed meiotic division (first division restitution and second division restitution); omission of the second division (the prevalent mechanism), irregular anaphase II (second division restitution; and failure of second cytokinesis (second Division restitution).Abstract:
The occurrence of 2n eggs in 381 haploids from six tetraploid parents and in 127 plants representing five diploid wild species was detected using 2x × 4x crosses. Sixty-two percent of the haploids and 24% of the wild-species plants produced 2n eggs. Twenty-six haploids and 17 species plants that gave high seed set in 2x × 4x crosses were examined cytologically to determine the frequency and mechanisms of 2n egg formation. There was significant variation in the frequency of 2n eggs among haploids (7–57%) and among species plants (4.9–57.3%). Five mechanisms of 2n egg formation were identified: synaptic variant (genetically first division restitution); delayed meiotic division (first division restitution and second division restitution); omission of the second division (the prevalent mechanism, second division restitution); irregular anaphase II (second division restitution); and failure of second cytokinesis (second division restitution). 2n eggs can be formed by more than one mechanism within a clone. The...read more
Citations
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Pathways, mechanisms, and rates of polyploid formation in flowering plants
TL;DR: The results indicate that the triploid bridge pathway can contribute significantly to autopolyploids formation regardless of the mating system, and to allopolyploid formation in outcrossing taxa.
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Gametes with the somatic chromosome number: mechanisms of their formation and role in the evolution of autopolyploid plants.
F. Bretagnolle,J. D. Thompson +1 more
TL;DR: The different methods used to detect and quantify the production of 2n gametes in plants are described, which include morphological and flow cytometry screening of the occurrence of2n pollen, the analysis of crosses among diploid and tetraploid parents and the instigation of micro-and mega-sporogenesis.
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The evolutionary dynamics of polyploid plants: origins, establishment and persistence.
TL;DR: The role of polyploidy in the origin of evolutionary novelty and the maintenance of diversity in plant populations has come to be recognized as an integral component of the ecological and evolutionary dynamics of plant species populations.
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Systematics, Diversity, Genetics, and Evolution of Wild and Cultivated Potatoes
TL;DR: A historical overview and update since 1990 of the systematics, diversity, genetics, domestication, evolution, and breeding of Solanum section Petota is provided that will serve as a reference for the next generation of studies in the potato.
Journal ArticleDOI
Sexual polyploidization in plants – cytological mechanisms and molecular regulation
Nico De Storme,Danny Geelen +1 more
TL;DR: The cytological mechanisms and molecular regulatory networks underlying 2n gamete formation are summarized, and important mitotic and meiotic processes involved in the ectopic induction of sexual polyploidization are outlined.
References
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Journal ArticleDOI
The significance of genic balance to endosperm development in interspecific crosses
S. A. Johnston,T. P. M. den Nijs,T. P. M. den Nijs,S. J. Peloquin,S. J. Peloquin,R. E. Hanneman,R. E. Hanneman +6 more
TL;DR: This hypothesis brings most intraspecific-interploidy and interspecific crossing data under a single concept with respect to endosperm function, and the implications to isolating mechanisms, 2n gametes, the evolution of disomic polyploids, and reciprocal differences in seed development are discussed.
Journal ArticleDOI
THREE MECHANISMS OF 2n POLLEN FORMATION IN DIPLOID POTATOES
D. W. S. Mok,Stanley J. Peloquin +1 more
TL;DR: Three mechanisms of 2n pollen formation observed in diploid hybrids between Solatium tuberosum Group Phureja (2x) and haploids of S. tuberculosis Group Tuberosum (4x) are termed parallel spindles (ps), premature cytokinesis 1 (pc 1) and premature cytokineis 2 (pc 2).
Journal ArticleDOI
Potato breeding with haploids and 2n gametes
TL;DR: Heterosis for total and marketable tuber yield and specific gravity occurs in 4x families from crosses between 4x cultivars and 2x haploid Tuberosum × 'Phureja' hybrids.
Journal ArticleDOI
Induction of chromosome doubling at meiosis by the elongate gene in maize.
M. M. Rhoades,Ellen Dempsey +1 more
TL;DR: A new meiotic gene is reported in this paper which will be a useful tool in cytogenetical studies with maize and evidence will be presented that the diploid eggs originate by chromosome doubling at the second meiotic division.
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