“…Recent studies in native species of the state of Rio Grande do Sul show irregularities in meiotic behavior similar to that of crem, but with a predominance of regularity and high pollen viability in lemon grass (Elionurus muticus) (Füller et al 2015), cherry tree accessions (Eugenia involucrata) (Guerra et al 2016), and Paspalum notatum tetraploidized plants (Krycki et al 2016). According to Pagliarini (2000), irregular chromosome segregation is the most common meiotic abnormality in both cultivated and native species, being characterized by the presence of chromosomes in precocious chromosome ascension and laggard choromosome.…”
The species Tropaeolum pentaphyllum Lam. (batata-crem or crem) is of great economic and medicinal importance. For being an endangered species, the knowledge of its genetic variability is necessary. Considering the lack of cytological studies on this species, this work describes the chromosome numbers, the meiotic behavior, the meiotic index, and the viability of the pollen grains of three populations of T. pentaphyllum from Rio Grande do Sul, Brazil. The three populations presented 2n = 28 chromosomes. Meiotic behavior was regular, with low abnormality frequency (<1%), which culminated in IMx> 90% in the three accessions. This meiotic stability resulted in high production of viable pollen grains, which will favor the use of these accessions in selection programs for commercial purposes, conservation and sustainable use.
“…Recent studies in native species of the state of Rio Grande do Sul show irregularities in meiotic behavior similar to that of crem, but with a predominance of regularity and high pollen viability in lemon grass (Elionurus muticus) (Füller et al 2015), cherry tree accessions (Eugenia involucrata) (Guerra et al 2016), and Paspalum notatum tetraploidized plants (Krycki et al 2016). According to Pagliarini (2000), irregular chromosome segregation is the most common meiotic abnormality in both cultivated and native species, being characterized by the presence of chromosomes in precocious chromosome ascension and laggard choromosome.…”
The species Tropaeolum pentaphyllum Lam. (batata-crem or crem) is of great economic and medicinal importance. For being an endangered species, the knowledge of its genetic variability is necessary. Considering the lack of cytological studies on this species, this work describes the chromosome numbers, the meiotic behavior, the meiotic index, and the viability of the pollen grains of three populations of T. pentaphyllum from Rio Grande do Sul, Brazil. The three populations presented 2n = 28 chromosomes. Meiotic behavior was regular, with low abnormality frequency (<1%), which culminated in IMx> 90% in the three accessions. This meiotic stability resulted in high production of viable pollen grains, which will favor the use of these accessions in selection programs for commercial purposes, conservation and sustainable use.
Angelonia integerrima Sprengel is a native species of the state of Mato Grosso do Sul and the Southern region (Paraná, Santa Catarina and Rio Grande do Sul) of Brazil, with features such as an unusual appearance and color of the flowers, indicating an ornamental use. To optimize the use of this species and to fill in gaps regarding its cytogenetic characterization, this study determined the chromosome number, meiotic index and pollen viability of plant individuals of four A. integerrima populations. All plant individuals of the four populations had 2n = 20 chromosomes. Still, the meiotic index of most analyzed plant individuals exceeded 90%, while pollen viability of all plant individuals was higher than 80%. These data suggest considerable cytological stability of the analyzed A. integerrima plant individuals, which may favor the selection of future genotypes for commercial purposes or their use in conservation and breeding programs of the species.
“…This work allowed observing satisfactory meiotic regularity of the three duplicated plants, and made them viable as parents in the breeding program. Guerra et al (2016) also recorded cytological stability of 35 cherry trees accessions (Eugenia involucrata DC) collected in the state of Rio Grande do Sul; the average of meiotic cells considered normal was 82.12% and the average pollen vi ability was 92.44%. The authors concluded that such native access can be used directly in commercial orchards, and also as male parents in directed crosses in breeding programs such as those presented in this work.…”
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