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Cytogenetic evidence indicates that Zea, which comprises maize (Z. mays ssp. mays) and its wild relatives, is an allopolyploid genus. Our research group has carried out numerous cytogenetic studies on Zea species, mainly focused on native Argentinian and Bolivian maize landraces. We found a wide inter- and intraspecific genome size variation in the genus, with mean 2C-values ranging between 4.20 and 11.36 pg. For the maize landraces studied here, it varied between 4.20 and 6.75 pg. The objectives of this work are to analyze the causes of genome size variation and to discuss their adaptive value in Zea. This variation is mainly attributed to differences in the heterochromatin located in the knobs and to the amount of interspersed DNA from retrotransposons. Polymorphisms in presence or absence of B-chromosomes (Bs) and the population frequency of Bs are also a source of genome size variation, with doses ranging between one and eight in the landraces analyzed here. Correlation analysis revealed that the percentage of heterochromatin is positively correlated with genome size. In addition, populations cultivated at higher altitudes, which are known to be precocious, have smaller genome sizes than do those growing at lower altitudes. This information, together with the positive correlation observed between the length of the vegetative cycle and the percentage of heterochromatin, led us to propose that it has an adaptive role. On the other hand, the negative relationship found between Bs and heterochromatic knobs allowed us to propose the existence of an intragenomic conflict between these elements. We hypothesize that an optimal nucleotype may have resulted from such intranuclear conflict, where genome adjustments led to a suitable length of the vegetative cycle for maize landraces growing across altitudinal clines.

In this work the relationship between genome size of Glandularia species and the meiotic configurations found in their hybrids are discussed. Glandularia incisa (Hook.) Tronc., growing in two localities of Corrientes and Córdoba provinces, Argentina, with different ecological conditions, showed inter-population variability of the 2C-value. The DNA content found in the Corrientes locality (2.41 pg) was higher than that obtained in the Córdoba locality (2.09 pg) which has more stressful environmental conditions than the former. These values are statistically different from those that were found in Glandularia pulchella (Sweet) Tronc. from Corrientes (1.43 pg) and in Glandularia perakii Cov. et Schn from Córdoba (1.47 pg). The DNA content of the diploid F1 hybrids, G. pulchella × G. incisa and G. perakii × G. incisa, differed statistically from the DNA content of the parental species, being intermediate between them. Differences in the frequency of pairing of homoeologous chromosomes were observed in the hybrids; these differences cannot be explained by differences in genome size since hybrids with similar DNA content differ significantly in their meiotic behavior. On the other hand, the differences in the DNA content between the parental species justify the presence of a high frequency of heteromorphic open and closed bivalents and univalents with different size in the hybrids.

A control-oriented model of a Dual Clutch Transmission (DCT) was developed for real-time Hardware In the Loop (HIL) applications, to support model-based development of the DCT controller and to systematically test its performance. The model is an innovative attempt to reproduce the fast dynamics of the actuation system while maintaining a simulation step size large enough for real-time applications. The model comprehends a detailed physical description of hydraulic circuit, clutches, synchronizers and gears, and simplified vehicle and internal combustion engine sub-models. As the oil circulating in the system has a large bulk modulus, the pressure dynamics are very fast, possibly causing instability in a real-time simulation; the same challenge involves the servo valves dynamics, due to the very small masses of the moving elements. Therefore, the hydraulic circuit model has been modified and simplified without losing physical validity, in order to adapt it to the real-time simulation requirements. The results of offline simulations have been compared to on-board measurements to verify the validity of the developed model, which was then implemented in a HIL system and connected to the Transmission Control Unit (TCU). Several tests have been performed on the HIL simulator, to verify the TCU performance: electrical failure tests on sensors and actuators, hydraulic and mechanical failure tests on hydraulic valves, clutches and synchronizers, and application tests comprehending all the main features of the control actions performed by the TCU. Being based on physical laws, in every condition the model simulates a plausible reaction of the system. A test automation procedure has finally been developed to permit the execution of a pattern of tests without the interaction of the user; perfectly repeatable tests can be performed for non-regression verification, allowing the testing of new software releases in fully automatic mode.

The karyotype of Elymus scabrifolius (Doll) J.H. Hunz. (2n = 4x = 28) was investigated by DAPI staining and in situ hybridization. All the accessions studied presented a symmetric and uniform karyotype constituted by 9m+2m-sm +3sm. DAPI stain showed 1-7 conspicuous bands in all the chromosomes and polymorphisms between accessions. FISH experiments carried out with 45S rDNA as probe (pTa71) showed strong hybridization signals on the metacentric SAT-chromosome pair 8; the submetacentric SAT-chromosome pair 13 presented weaker hybridization. FISH using pSc119.2 clone as probe identified five chromosome pairs. Then, the combination of chromosome morphology, DAPI- staining, and FISH enabled the accurate identification of each chromosome pair in E. scabrifolius. Genomic in situ hybridization (GISH) experiments using Hordeum DNA as probe on mitotic metaphases confirmed unequivocally the presence of the H genome in E. scabrifolius, allowing us to observe six uniformly labeled chromosome pairs and two chromosome pairs with only one arm labeled. The remaining six chromosome pairs were weakly labeled. The rehybridization of FISH slides with Hordeum DNA as probe allow us to assign the genomic provenance of most of the chromosomes in the studied accessions. Moreover, intergenomic rearrangement was detected between genome H and the still unknown progenitor genome. Key words: Elymus scabrifolius, karyotype, FISH, GISH, intergenomic rearrangement. Le caryotype de l'Elymus scabrifolius (Doll) J.H. Hunz. (2n = 4x = 28) a ete etudie par coloration au DAPI et par hybridation in situ. Toutes les accessions etudiees ont presente un caryotype symetrique et uniforme compose de 9m +2m-sm+3sm. La coloration au DAPI a revele de 1 a 7 bandes majeures chez tous les chromosomes et du polymorphisme entre les accessions. Les analyses FISH realisees au moyen d'une sonde d'ADNr 45S (pTa71) ont produit de forts signaux sur la paire 8 de chromosomes-SAT metacentriques. La paire 13 de chromosomes-SAT submetacentriques presentait une plus faible hybridation. L'analyse FISH avec la sonde pSc119,2 a permis d'identifier cinq paires de chromosomes. Ensuite, en combinant la morphologie chromosomique, la coloration au DAPI et l'analyse FISH, il a ete possible d'identifier chaque paire de chromosomes chez l'E. scabrifolius. Des analyses d'hybridation genomique in situ (GISH) avec l'ADN d'Hordeum comme sonde sur des chromosomes en metaphase mitotique a clairement confirme la presence du genome H au sein de l'E. scabrifolius et a permis d observer six paires de chromosomes uniformement marques ainsi que deux paires de chromosomes marques uniquement sur un bras. Les six autres paires de chromosomes etaient faiblement marques. La re- hybridation des lames utilisees lors des analyses FISH avec l ADN d Hordeum a permis de determiner la provenance genomique de la plupart des chromosomes chez les accessions etudiees. De plus, un rearrangement genomique a ete detecte entre le genome H et un autre genome inconnu. Mots-cles : Elymus scabrifolius, caryotype, FISH, GISH, rearrangement intergenomique. [Traduit par la Redaction], Introduction The genus Elymus L. (Triticeae, Poaceae) is a complex group composed of approximately 150 perennial species. The species of Elymus are allopolyploids characterized by a genome combination of several [...]

In the present work we report new tools for the characterization of the complete chromosome complement of sunflower (Helianthus annuus L.), using a bacterial artificial chromosome (BAC) clone containing repetitive sequences with similarity to retrotransposons and a homologous rDNA sequence isolated from the sunflower genome as probes for FISH. The rDNA signal was found in 3 pairs of chromosomes, coinciding with the location of satellites. The BAC clone containing highly represented retroelements hybridized with all the chromosome complement in FISH, and used together with the rDNA probe allowed the discrimination of all chromosome pairs of sunflower. Their distinctive distribution pattern suggests that these probes could be useful for karyotype characterization and for chromosome identification. The karyotype could be subdivided into 3 clear-cut groups of 12 metacentric pairs, 1 submetacentric pair, and 4 subtelocentric pairs, thus resolving previously described karyotype controversies. The use of BAC clones containing single sequences of specific markers and (or) genes associated with important agricultural traits represents an important tool for future locus-specific identification and physical mapping. Key words: karyotype, BAC-FISH, rDNA, repetitive elements, sunflower, Helianthus annuus. Dans le present travail, les auteurs rapportent de nouveaux outils pour la caracterisation du jeu chromosomique complet chez le tournesol (Helianthus annuus L.) au moyen d'analyses FISH avec une sonde BAC contenant des sequences repetees presentant de l'homologie avec des retrotransposons et avec une sequence homologue d'ADNr isolee dugenome du tournesol. Des sites chromosomiques de l'ADNr ont ete observes sur trois paires de chromosomes, lesquels coincidaient avec l'emplacement de satellites. Le clone BAC contenant des retroelements tres presents dans le genome a hybride avec tous les chromosomes en analyse FISH et, employee conjointement avec la sonde d'ADNr, a permis de distinguer toutes les paires de chromosomes du tournesol. La distribution distinctive de ces sequences repetees suggere qu'elles pourraient servir pour la caracterisation du caryotype et pour l'identification des chromosomes. Ainsi, le caryotype se diviserait en trois groupes nets formes de 12 paires metacentriques, une paire submetacentrique et quatre paires subtelocentriques. Cela permettrait ainsi de mettre fin a des controverses au sujet du caryotype. De plus, l'emploi de sequences BAC represente un outil important en vue d'une future identification de locus specifiques et de la cartographie physique a l'aide de clones BAC contenant des sequences uniques pour certains marqueurs ou genes specifiques lies a des caracteres agronomiques importants. Mots-cles: caryotype, BAC-FISH, ADNr, elements repetes, tournesol, Helianthus annuus. [Traduit par la Redaction], Introduction Cultivated sunflower (Helianthus annuus L.) is one of the most important sources of vegetable oil in the world. Reliable cytological techniques for chromosome identification are necessary for efficient genome [...]