Complete asynapsis resulting in 2n pollen formation in Paspalum jesuiticum Parodi (Poaceae)

Filho, R.A. Bernardo; Santos, Adauto; Souza, Francisco Humberto Dübbern de; Valls, J. F. M.; Pagliarini, Maria Suely

doi:10.4238/2014.january.17.9

Cited by 8 publications

(3 citation statements)

References 29 publications

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“…During microsporogenesis, abnormal meiotic behavior is related to the formation of 2n pollen, such as an in asynapsis [43], the distribution of microtubular cytoskeletons and organelle nucleoids in hybrid Populus [44], as well as deviations in the spatial configuration of both MT (microtubule)s and MF (microfilament)s of Solanum [45]. Furthermore, the production of 2n pollen in plants is mainly controlled by genes.…”

Section: Discussionmentioning

confidence: 99%

The strong competitive role of 2n pollen in several polyploidy hybridizations in Rosa hybrida

et al. 2019

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Background 2n pollen play a strong competitive role in hybridization and breeding of multiploids in Rosa hybrida . The ploidy inheritable characteristic of ‘Orange Fire’ × ‘Old Blush’ were analyzed. Result The results of the cytological observations indicated that 2n pollen developed from the defeated cytoplasmic division or nuclear division in the meiosis metaphase II of PMC (pollen mother cell) in ‘Old Blush’. The natural generation rate of the 2n pollen in ‘Old Blush’ (2x) was about 1.39 in percentage of all male gametes, whereas the tetraploids in the F1 offspring possessed a high rate, i.e., 44.00%. The temporal and spatial characteristics of ‘Old Blush’ pollen germination on the stigma and growth in pistil of ‘Orange Fire’ and ‘DEE’ were observed, and the results suggested that the germination rate of 2n pollen on the stigma was not superior to that of 1n pollen, but that the proportion of 2n pollen increased to 30.90 and 37.20%, respectively, while it traversed the stigma and entered into style. The callose plug in the 2n pollen tube was significantly thinner than that of 1n pollen tube. And each trait involved in our experiment probably is very important for F1 morphological phenotypes. Conclusion We conclude that 2n pollen are involved in hybridization and have a competitive advantage while it traversed the stigma and entered into style. The callose plug in the 2n pollen tube was may have strongly influenced the competitive process in R. hybrida . Electronic supplementary material The online version of this article (10.1186/s12870-019-1696-z) contains supplementary material, which is available to authorized users.

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Section: Discussionmentioning

confidence: 99%

The strong competitive role of 2n pollen in several polyploidy hybridizations in Rosa hybrida

et al. 2019

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“…According to Bernardo Filho et al. (2014), this accession of P. jesuiticum has 60 chromosomes and the accession of P. subciliatum has 40 chromosomes (Adamowski et al., 1998; Pagliarini et al., 1999). Therefore, the observed reproduction mode is compatible with the polyploid character of the accessions.…”

Section: Discussionmentioning

confidence: 99%

Characterization of Paspalum genotypes for turfgrass cultivars development

Matta,

Fávero,

Vigna

et al. 2024

Crop Science

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The characterization of genetic resources is essential to carry out a breeding program. This study aimed to characterize Paspalum genotypes with potential use as soil surface covering to support breeding programs on the development of turf cultivars. Forty‐three Paspalum genotypes, comprising 11 species, were evaluated. The embryo‐sacs structure was determined by cleared ovaries analysis and eight accessions were classified as sexual, 15 as apomictic, and 20 presenting facultative apomixis. Most of the genotypes have 40 chromosomes, with the exception of one accession of Paspalum vaginatum, two of Paspalum indecorum, one of Paspalum modestum, and two of Paspalum notatum that have 20 and one accession of Paspalum jesuiticum and one of Paspalum mandiocanum that have 60 chromosomes. DNA content was determined by flow cytometry, ranging from 1.35 to 4.00 pg of DNA, with most of the accessions corresponding to tetraploidy, but also diploidy and hexaploidy were found, corroborating chromosome counts. High genetic variability was found among the 43 accessions based on 11 microsatellite markers and their use to estimate Jaccard similarity coefficients and Bayesian analysis, forming six different genetic groups. Considering only the P. notatum accessions, great variability was observed with four distinct groups formed. The results presented in this work reveal the possibility to obtain assertive crosses between compatible parents, aiming to explore the genetic variability between and within species of this genus.

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“…SDM has been shown to co-occur with either FDR or SDR in individual Triticeae hybrids [ 13 – 15 ]. Meiotic nonreduction through SDM has also been reported in a non-hybrid synaptic mutant of Paspalum jesuiticum [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

Asynapsis and unreduced gamete formation in a Trifolium interspecific hybrid

et al. 2022

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Background Unreduced gametes, a driving force in the widespread polyploidization and speciation of flowering plants, occur relatively frequently in interspecific or intergeneric hybrids. Studies of the mechanisms leading to 2n gamete formation, mainly in the wheat tribe Triticeae have shown that unreductional meiosis is often associated with chromosome asynapsis during the first meiotic division. The present study explored the mechanisms of meiotic nonreduction leading to functional unreduced gametes in an interspecific Trifolium (clover) hybrid with three sub-genomes from T. ambiguum and one sub-genome from T. occidentale. Results Unreductional meiosis leading to 2n gametes occurred when there was a high frequency of asynapsis during the first meiotic division. In this hybrid, approximately 39% of chromosomes were unpaired at metaphase I. Within the same cell at anaphase I, sister chromatids of univalents underwent precocious separation and formed laggard chromatids whereas paired chromosomes segregated without separation of sister chromatids as in normal meiosis. This asynchrony was frequently accompanied by incomplete or no movement of chromosomes toward the poles and restitution leading to unreduced chromosome constitutions. Reductional meiosis was restored in progeny where asynapsis frequencies were low. Two progeny plants with approximately 5 and 7% of unpaired chromosomes at metaphase I showed full restoration of reductional meiosis. Conclusions The study revealed that formation of 2n gametes occurred when asynapsis (univalent) frequency at meiosis I was high, and that normal gamete production was restored in the next generation when asynapsis frequencies were low. Asynapsis-dependent 2n gamete formation, previously supported by evidence largely from wheat and its relatives and grasshopper, is also applicable to hybrids from the dicotyledonous plant genus Trifolium. The present results align well with those from these widely divergent organisms and strongly suggest common molecular mechanisms involved in unreduced gamete formation.

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Complete asynapsis resulting in 2n pollen formation in Paspalum jesuiticum Parodi (Poaceae)

Cited by 8 publications

References 29 publications

The strong competitive role of 2n pollen in several polyploidy hybridizations in Rosa hybrida

The strong competitive role of 2n pollen in several polyploidy hybridizations in Rosa hybrida

Characterization of Paspalum genotypes for turfgrass cultivars development

Asynapsis and unreduced gamete formation in a Trifolium interspecific hybrid

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