Gametas Não Reduzidos No Melhoramento De Plantas

Schifino-Wittmann, María Teresa; Dall'Agnol, Miguel

doi:10.1590/s0103-84782001000100028

Cited by 10 publications

(6 citation statements)

References 27 publications

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“…In this case, meiosis II occurs normally, resulting in a dyad instead of triad, though (which was already expected). This division (RFD) occurs when the plants in which pairing between homologues or homeologues (interspecific hybrids) is completely absent as in synaptic mutants or distant hybrids and in plants whose cytokinesis is of the successive type as is the case of most dicots (Schifino-Wittmann & Dall'Agnol, 2001;Ramanna & Jacobsen, 2003). The other way to form 2n gametes is in meiosis II, by the restitution in the second division (RSD), in which a cytokinesis failure and diploid restitution nucleus (with formation of dyads or triads) can be verified (Ramanna & Jacobsen, 2003).…”

Section: Resultsmentioning

confidence: 99%

Meiotic behavior and fertility of Capsicum interspecific hybrids

et al. 2020

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This study was performed to evaluate the meiotic behavior and fertility of four hybrids obtained from the crossing of Capsicum baccatum and its botanical forms with Capsicum chinense and Capsicum frutescens. We aimed to identify the causes of the low fertility in interspecific hybrids involving species from different gene pools of Capsicum. Hybrid flower buds were fixed in fixative solution and the slides were prepared using 1%-acetic carmine solution. Meiosis was observed in all phases and the main meiotic abnormality observed was the complete or partial lack of chromosome pairing, indicating that the species are either genetically distant or that some asynaptic gene was present in the hybrids. Meiotic index (MI), the frequency of unreduced gametes (type 2n), and pollen viability were estimated. MI and pollen viability of the hybrids were low. We concluded that due to the complete or partial lack of chromosome pairing, the species used in the hybrid combinations are genetically distant. We also noticed that the low-fertility hybrids are a consequence of the lack of chromosome homology between the two genomes involved. The hybrids were considered partially sterile since their pollen viability percentage was lower than 50%.

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Section: Resultsmentioning

confidence: 99%

Meiotic behavior and fertility of Capsicum interspecific hybrids

et al. 2020

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“…Evaluation of hybrids may demonstrate diversity, considering that the genotypes will express a combination of parental genes (Capocasa et al, 2008). In addition, when the ploidization phenomenon occurs spontaneously in nature through the union of non-reduced gametes (Schifino-Wittmann and Dall'Agnol, 2001), the increase in the number of chromosome sets in the evolution of a species can result in greater variability and higher heterozygosity, vigor, and adaptability (Schifino-Wittmann, 2004). Strawberry is an octoploid and has undergone several levels of ploidization throughout its evolutionary history and may present a high variability in hybrids obtained from crosses (Hancock et al, 2008).…”

Section: Resultsmentioning

confidence: 99%

Research Article Yield and quality of strawberry hybrids under subtropical conditions

Barth¹,

Resende²,

Zeist³

et al. 2019

Genet. Mol. Res.

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Strawberry (Fragaria x ananassa) stands out among small fruits as the most planted in Brazil, generating considerable income and employment. However, producers are dependent on cultivars originating from international breeding programs and imported seedlings. This entails high costs and plants poorly adapted to the edaphoclimatic conditions of Brazil. In addition, the consumer market demands superior organoleptic and nutritional qualities. We assessed the potential of 194 hybrids for production and physicochemical characteristics from a population of seedlings obtained from intraspecific crosses of the short-day cultivars Dover, Camarosa, Sweet Charlie, Oso Grande, Milsei Tudla, and Festival Florida and the day-neutral cultivar Aromas. The experimental design was an augmented block design that had as control treatments the cultivars Camarosa and Camino Real. Five production and nine physicochemical characteristics were assessed. The mean comparison was performed by the Dunnett test. Among the 14 characteristics analyzed, eight presented significance. The significant production characteristics were the number of commercial fruits, mass of commercial fruits, mass of non-commercial fruits, and the total mass ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 18 (2): gmr18156 E. Barth et al. 2 of fruits, with values of 45.03 fruits/plant, 13.17 g, 72.22 g/plant, and 720.77 g/plant, respectively. The physicochemical characteristics that varied significantly were soluble solids to titratable acidity ratio, pectin, ascorbic acid, and anthocyanin, which presented values of 10.23, 2.06 g total pectin/100 g pulp, 71.12 mg ascorbic acid/100 g pulp, and 39.51 mg cyanidin 3-glycoside/100 g pulp, respectively. The crosses that involved Camarosa and Aromas gave a greater number of hybrids with superior positive effects when compared to the controls in terms of production and physicochemical characteristics, respectively. Among the 194 hybrids, 30 were superior to the controls and were selected to advance in the breeding program.

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“…This phenomenon can occur spontaneously in almost all plants or may increase with interspecific crosses and environmental factors (Schifino-Wittmann and Dall'Agnol, 2001). Unreduced gametes were observed in some species of Brassica at low frequencies; however, in interspecific hybrids, the frequency was higher.…”

Section: Meiotic X Fertility Irregularities In Plantsmentioning

confidence: 99%

Research Article Contributions of classical and molecular cytogenetic in meiotic analysis and pollen viability for plant breeding.

et al. 2017

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ABSTRACT. The analysis of meiotic behavior has been widely used in the study of plants as they provide relevant information about the viability of a species. Meiosis boasts a host of highly conserved events and changes in genes that control these events will give rise to irregularities that can alter the normal course of meiosis and may lead to complete sterility of the plant. The recombination of genes that occur in meiosis is an important event to generate variability and has been important in studies for genetic improvement and to create viable hybrids. The use of fluorescence in situ hybridization and genomic in situ hybridization (GISH) in meiosis allows the localization of specific regions, enables to differentiate genomes in a hybrid, permits to observe the pairing of homoeologous chromosomes, and if there was a recombination between the genomes of progenitor species. Furthermore, the GISH allows us to observe the close relationship between the species involved. This article aims to report over meiosis studies on plants and hybrids, the use and importance of molecular cytogenetic in meiotic analysis and contributions of meiotic analysis in breeding programs.

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Gametas Não Reduzidos No Melhoramento De Plantas

Abstract: RESUMO Nesta revisão são abordados o papel dos gametas não reduzidos (gametas 2n), ou seja, aqueles com o número somático de cromossomos, na origem dos poliplóides

Cited by 10 publications

References 27 publications

Meiotic behavior and fertility of Capsicum interspecific hybrids

Meiotic behavior and fertility of Capsicum interspecific hybrids

Research Article Yield and quality of strawberry hybrids under subtropical conditions

Research Article Contributions of classical and molecular cytogenetic in meiotic analysis and pollen viability for plant breeding.

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