Showing papers by "Lidia Poggio published in 2011"
TL;DR: It is proposed that maize shows lower genomic affinity to Z. luxurians than to other species of the genus with 2n = 20, suggesting postzygotic reproductive isolation among their parents.
Abstract: The karyotypes of Zea luxurians and a race of maize from northwestern Argentina are described and compared using 4′,6-diamidino-2-phenylindole (DAPI) banding and fluorescent in situ hybridization (FISH) to localize the 180 bp knobs. The meiotic behavior of the F1 artificial hybrids Z. luxurians × maize is also analyzed to determine the genomic relationships between both species. Neocentromere activity at knobs in the meiosis of the hybrids is particularly discussed. The meiotic behavior and the high pollen sterility of the hybrid revealed genetical and (or) chromosomal divergences, leading to postzygotic reproductive isolation among their parents. Here, we propose that maize shows lower genomic affinity to Z. luxurians than to other species of the genus with 2n = 20.
16 citations
TL;DR: The relationship between total chromosome length and climatic parameters showed that diploid species of marginal areas of distribution have a larger chromosome size, and that this could be related with mechanisms of ecologi- cal adaptation.
Abstract: In this work we studied the chromosome number and karyotype formula of seven species of Mi- mosa L. (Mimosoideae, Leguminosae). The chromosome number 2n = 2x = 26 for M. detinens Benth., M. hex- andra M. Micheli, M. ostenii Speg. ex Burkart and M. xanthocentra Mart. var. mansii (Benth.) Barneby are new records, while the chromosome number 2n = 2x = 26 for M. debilis var. debilis, M. uruguensis Hook. and Arn. and M. uliginosa Chodat and Hassl. confirm previous records. Karyotype formulae revealed the existence of metacentric and submetacentric chromosomes, and the chromosomal asymmetry indexes did not show significant differences between taxa. The chromosome length of xerophilous and endemic M. detinens and M. ostenii differed from the rest of species, indicating that this parameter could have taxonomic value. In addition, the relationship between total chromosome length and climatic parameters showed that diploid species of marginal areas of distribution have a larger chromosome size, and that th...
10 citations
TL;DR: Progress in localizing single-copy sequences using BAC-FISH and indirect C-PRINS strategies in sunflower will facilitate the integration of genetic and physical maps, allowing the identification of chromosomes containing key genes and/or QTL associated to agronomic important traits in sunflowers.
Abstract: Bacterial artificial chromosome - fluorescence in situ hybridization (BAC-FISH) and cyclingprimed in situ labeling (C-PRINS) techniques were evaluated for integration of physical and genetic maps of sunflower (Helianthus annuus L.). Single-site SSR markers were selected from three linkage groups of a high-density sunflower genetic map. This selection was based on previously identified QTL associated to S. sclerotiorum. These markers were used to select BACs contaning single copy sequences for BAC-FISH aplication. Blocking of highly dispersed repetitive sunflower sequences reduced unspecific hybridization, and allowed the detection of specific signals for BACs containing SSR markers HA4222 and HA2600, anchored to LG 16 and LG 10, respectively. Single-site FISH signal detection was optimized by adjusting the relative quantity and quality of unlabelled repetitive sequences present in the blocking DNA. The SSR marker ORS1247 anchored to the LG 17 was detected by C-PRINS, which yielded fluorescence signals that were specific and intense. This progress in localizing single-copy sequences using BAC-FISH and indirect CPRINS strategies in sunflower will facilitate the integration of genetic and physical maps, allowing the identification of chromosomes containing key genes and/or QTL associated to agronomic important traits in sunflower
10 citations
TL;DR: The Turnera ulmifolia complex showed an increase in total DNA content in the ploidy level, but not in the expected proportion, and the general tendency indicated a decrease in the 1Cx-value with increasing chromosome number.
Abstract: Turnera ulmifolia constitutes a well-studied polyploid complex with allo- and autopolyploid species ranging from 2 to 8x. Flow cytometry was used to determine nuclear DNA content, and to estimate 2C- and 1Cx-values with the aim of analysing the genome size in Turnera in terms of polyploid speciation. The 2C-value and 1Cx-value were evaluated in 12 species of the T. ulmifolia complex. Nuclear DNA content was estimated by flow cytometry of nuclei stained with propidium iodide. The 2C DNA content ranged from 1.38 to 1.83 pg in diploids, from 2.67 to 3.96 pg in tetraploids, from 2.73 to 4.31 pg in hexaploids, and from 3.53 to 5.90 pg in octoploids. The 1Cx-value ranged from 0.44 to 0.99 pg. The Turnera ulmifolia complex showed an increase in total DNA content in the ploidy level, but not in the expected proportion. The general tendency indicated a decrease in the 1Cx-value with increasing chromosome number, with T. grandidentata 4x being an outstanding exception. The 1Cx-values in the allooctoploids T. aurelii and T. cuneiformis differed by 1.6-fold from each other, probably as a result of different evolutionary histories following divergence from the last common ancestor.
7 citations
Journal Article•
TL;DR: The results suggest that specimens of I. dumosa studied herein represent an interesting reservoir of genetic variability, highly adequate for improvement of yerba mate lines, and support the reinforcement of conservation strategies aiming at the expansion of the I. paraguariensis genetic pool deposited in the Germplasm Bank.
Abstract: Palabras clave: AFLP, yerba mate, yerba senorita, germoplasma, diferenciacion genetica. Summary: Ilex paraguariensis and Ilex dumosa (Aquifoliaceae) germplasm evaluation. Ilex paraguariensis and I. dumosa are species with great economic relevance in Argentina. Both species share several features of their biology, though they differ in phytochemical composition and in their resistance to biotic and abiotic factors. The aim of the present work is to evaluate the structure of the genetic diversity of the plants kept at the Germplasm Bank of Yerba Mate (EEINTACA) and also of commercial materials of yerba mate, through a re-analysis of AFLP data and a characterization of the nucleotide sequences of selected AFLP bands. For I. dumosa we have detected a molecular variation level two times higher than the value obtained for I. paraguariensis and a lower number of diagnostic bands in respect to the latter species. Reported nucleotide sequences, characterized using bioinformatic tools, are new sequences for the genus Ilex. Our results suggest that specimens of I. dumosa studied herein represent an interesting reservoir of genetic variability, highly adequate for improvement of yerba mate lines. Moreover, our results support the reinforcement of conservation strategies aiming at the expansion of the I. paraguariensis genetic pool deposited in the Germplasm Bank.
6 citations
Journal Article•
TL;DR: El objetivo del presente trabajo fue determinar, en ambas lineas mencionadas anteriormente, el porcentaje promedio de heterocromatina presente en los cromosomas de centeno y relacionar this valor with caracteristicas of the meiosis y of las semillas.
Abstract: Al cruzar un triticale hexaploide (2n=6x=42) y un trigopiro octoploide (2n=8x=56) se obtuvo, en 1972, un hibrido denominado tricepiro. Entre las lineas que se lograron estan tricepiro Don Rene INTA que posee semillas arrugadas y FA-L2 con semillas lisas. El contenido de heterocromatina de los cromosomas de centeno en otros hibridos intergenericos ha sido relacionado con la rugosidad y peso de las semillas, asi como con la presencia de anormalidades meioticas. El objetivo del presente trabajo fue determinar, en ambas lineas mencionadas anteriormente, el porcentaje promedio de heterocromatina presente en los cromosomas de centeno y relacionar este valor con caracteristicas de la meiosis y de las semillas. Confirmamos que las dos lineas tienen el mismo numero cromosomico (2n=42) y el mismo numero de cromosomas de centeno (14). Encontramos que ambas presentan un apareamiento completo de los cromosomas hasta diacinesis tardia, pero difieren en el porcentaje de celulas con univalentes fuera de la placa ecuatorial en Metafase I (Don Rene 42,.85 % y FA-L2 14,00 %). Ademas, ambas lineas difieren en el Indice Meiotico (Don Rene 66,47 % y FA-L2 87,90 %) y en el peso de las semillas (Don Rene 0,029 ± 0,000 g y FA-L2 0,038 ± 0,001 g). El analisis de las bandas C, hecho en metafases mitoticas, indico que el porcentaje promedio del contenido de heterocromatina presente en los cromosomas de centeno, no difiere significativamente entre las dos lineas. Contrariamente a nuestras expectativas, el comportamiento meiotico y las caracteristicas de las semillas no mostraron relacion con el porcentaje de heterocromatina presente en los cromosomas de centeno de las lineas hibridas estudiadas