"Trigopiros" derive from crosses between different species of Triticum L. and Thinopyrum Löve. These synthetic amphiploids are designed with the aim to obtain cereals similar to wheat but which are perennial, resistant to diseases and to the salinity of the soils. Moreover, they allow the transfer of the agronomic attributes of Thinopyrum to wheat. "Trigopiro" Don Noé INTA, which is currently grown in Argentina, presents valuable agronomic traits as well as a high content of seed proteins. In the present work, the use of classical cytogenetic techniques allowed us to confirm that the chromosome number of "Trigopiro" Don Noé is 2n=56. The application of in situ hybridization (FISH-GISH) allowed us to postulate its genomic composition for the first time. This artificial hybrid has 14 chromosomes from genome J of Thinopyrum and 2 chromosomes pairs with putative translocations between Triticum and Thinopyrum. The rest of chromosomes belong to A, B and D genomes of Triticum.

Caracterización del genoma de un Triticum x Thinopyrum (Poaceae) sintético amfiploide utilizando hibridación in situ. Los "Trigopiros" derivan de cruzamientos entre diferentes especies de Triticum y Thinopyrum. El objetivo es obtener cereales con características similares al trigo, perennes, resistentes a enfermedades y a la salinidad de los suelos. Además estos híbridos sintéticos son útiles para transferir al trigo atributos agronómicos de Thinopyrum. "Trigopiro" Don Noé INTA, que se cultiva actualmente en Argentina, presenta rasgos agronómicos valiosos, así como un alto contenido de proteínas seminales. En el presente trabajo se confirmó que el número de cromosomas de "Trigopiro" Don Noé es 2n = 56. Técnicas de hibridación in situ (FISH-GISH) permitieron postular su composición genómica desconocida hasta el momento. Este híbrido artificial posee 14 cromosomas del genoma J de Thinopyrum y 2 pares de cromosomas con posibles translocaciones entre Triticum y Thinopyrum. El resto de los cromosomas pertenecen a los genomas A, B y D de Triticum.

A hybrid, named tricepiro, was obtained in 1972, by crossing a hexaploid triticale (2n=6x=42) and an octoploid trigopiro (2n=8x=56). The lines achieved include the tricepiro Don René INTA, which has shriveled kernels, and FA-L2, which has smooth ones. The relationship between the heterochromatin content of the rye chromosomes, the seed weight, the presence of meiotic abnormalities and the kernel shriveling has been documented previously in other intergeneric hybrids. The purpose of this study was to determine the average percentage of heterochromatin content in the rye chromosomes of the two tricepiro lines mentioned above and to relate this feature to some characteristics of the meiosis and seeds. We confirmed that the two lines have the same total chromosome number (2n=42) and the same number of rye chromosomes (14). We found that both lines have a complete chromosome mating until late diakinesis, but differ in the percentage of cells with univalents outside the equatorial plate in Metaphase I (Don René 42.85% and FA-L2 14.00%). In addition, the two lines differed in their meiotic index (Don René 66.47% and FA-L2 87.90%) and seed weight (Don René 0.029 ± 0.000 g and FA-L2 0.038 ± 0.001 g). The C-banding in rye chromosomes in mitotic metaphase indicated that the average percentage of heterochromatin content did not differ significantly between the two lines. In contrast to our expectations, the meiotic behavior and seed characteristics were not related to the heterochromatin percentage of the rye chromosomes of the tricepiro lines studied.

Al cruzar un triticale hexaploide (2n=6x=42) y un trigopiro octoploide (2n=8x=56) se obtuvo, en 1972, un híbrido denominado tricepiro. Entre las líneas que se lograron están tricepiro Don René INTA que posee semillas arrugadas y FA-L2 con semillas lisas. El contenido de heterocromatina de los cromosomas de centeno en otros híbridos intergenéricos ha sido relacionado con la rugosidad y peso de las semillas, así como con la presencia de anormalidades meióticas. El objetivo del presente trabajo fue determinar, en ambas líneas mencionadas anteriormente, el porcentaje promedio de heterocromatina presente en los cromosomas de centeno y relacionar este valor con características de la meiosis y de las semillas. Confirmamos que las dos líneas tienen el mismo número cromosómico (2n=42) y el mismo número de cromosomas de centeno (14). Encontramos que ambas presentan un apareamiento completo de los cromosomas hasta diacinesis tardía, pero difieren en el porcentaje de células con univalentes fuera de la placa ecuatorial en Metafase I (Don René 42,.85 % y FA-L2 14,00 %). Además, ambas líneas difieren en el Índice Meiótico (Don René 66,47 % y FA-L2 87,90 %) y en el peso de las semillas (Don René 0,029 ± 0,000 g y FA-L2 0,038 ± 0,001 g). El análisis de las bandas C, hecho en metafases mitóticas, indicó que el porcentaje promedio del contenido de heterocromatina presente en los cromosomas de centeno, no difiere significativamente entre las dos líneas. Contrariamente a nuestras expectativas, el comportamiento meiótico y las características de las semillas no mostraron relación con el porcentaje de heterocromatina presente en los cromosomas de centeno de las líneas híbridas estudiadas.

We studied three different tricepiros: (Don Santiago x Don Noé), (Cumé x Horovitz) and (Cumé x Don Noé). The tricepiro (Don Santiago x Don Noé) was obtained by crossing the triticale Don Santiago INTA (AABBRR, 2n = 6x = 42) with the trigopiro Don Noé INTA (AABBDDJJ, 2n = 8x = 56). The number of chromosomes for the F1 was 2n = 49, the most frequent meiotic configuration being 14 bivalents and 21 univalents. The univalents were situated in the periphery of the equatorial plane, whereas the bivalents were located in the central zone. The chromatids in some of the univalents split when bivalents underwent reductional division in anaphase I. There were few laggard chromosomes or chromatids at this phase. The number of chromosomes (2n = 48-58) was high and variable, and the number of bivalents per cell (18-23) also high in F3 individuals. In all F8 tricepiros (Don Santiago x Don Noé), F12 tricepiros (Cumé x Horovitz) and F12 tricepiros (Cumé x Don Noé), the number of chromosomes (2n = 42) was the same, these retaining the rye genome, as demonstrated by GISH and FISH. These new synthesized allopolyploids constitute interesting models for investigating the evolutionary changes responsible for diploidization, and the chromosomal and genomic re-ordering that cannot be revealed in natural allopolyploids.