Intraspecific phylogeny of a Patagonian fescue: differentiation at molecular markers and morphological traits suggests hybridization at peripheral populations.

BACKGROUND AND AIMS: Grasses of the Festuca genus have complex phylogenetic relations due to morphological similarities among species and interspecific hybridization processes. Within Patagonian fescues, information concerning phylogenetic relationships is very scarce. In Festuca pallescens, a widely distributed species, the high phenotypic variability and the occurrence of interspecific hybridization preclude a clear identification of the populations. Given the relevance of natural rangelands for livestock production and their high degradation due to climate change, conservation actions are needed and knowledge about genetic variation is required. METHODS: To unravel the intraspecific phylogenetic relations and to detect genetic differences, we studied 21 populations of the species along its natural geographical distribution by coupling both molecular [internal transcribed spacer (ITS) and trnL-F markers] and morpho-anatomical analyses. Bayesian inference, maximum likelihood and maximum parsimony methods were applied to assemble a phylogenetic tree, including other native species. The morphological data set was analysed by discriminant and cluster analyses. KEY RESULTS: The combined information of the Bayesian tree (ITS marker), the geographical distribution of haplotype variants (trnL-F marker) and the morpho-anatomical traits, distinguished populations located at the margins of the distribution. Some of the variants detected were shared with other sympatric species of fescues. CONCLUSIONS: These results suggest the occurrence of hybridization processes between species of the genus at peripheral sites characterized by suboptimal conditions, which might be key to the survival of these populations.

Contribución del mejoramiento genético de festuca alta (Festuca arundinacea Schreb.) en Argentina: síntesis de los logros y avances / Contribution of the genetic improvement of tall fescue (Festuca arundinacea Schreb.) in Argentina: synthesis of achievements and advances

RESUMEN La festuca alta (Festuca arundinacea Schreb.), está representada en la Argentina por poblaciones adaptadas del morfotipo continental, que son largamente persistentes. Es la principal especie forrajera perenne cultivada en la región templada en el país, productora de forraje en pastoreo directo. En este trabajo se presenta el desarrollo del mejoramiento genético y la contribución del mismo para el logro de una mayor productividad y mejor valor nutritivo con cultivares sintéticos modernos. Los caracteres considerados fueron: adaptación y persistencia en ambientes adversos, digestibilidad, flexibilidad de lámina de la hoja, y tolerancia a roya. Los cultivares más representativos de las etapas y criterios de selección considerados en este trabajo fueron: Pergamino El Palenque MAG, Palenque Plus INTA, Brava INTA, Baguala y Luján INTA.

ABSTRACT Tall fescue (Festuca arundinacea Schreb.) is represented in Argentina by adapted populations of the continental morphotype, which are long persistent. It is the main perennial forage species cultivated in the temperate region of the country, producing forage for extensive grazing. The development of fescue plant breeding and its contribution to the achievement of higher productivity and better nutritional value with modern synthetic cultivars was the aim of this project. The characters considered were: adaptation and persistence in adverse environments, digestibility, leaf softness and tolerance to rust. The most representative cultivars of the stages and selection criteria considered in this work were: Pergamino El Palenque MAG, Palenque Plus INTA, Brava INTA, Baguala and Luján INTA.

Brote de "pie de festuca" en un rodeo de cría de Salta, Argentina / Outbreak of fescue foot in a livestock in Salta, Argentina

Festuca arundinacea es una gramínea perenne de uso forrajero muy difundida mundialmente. Aquí se describe un brote de “pie de festuca” en el Noroeste Argentino que afectó a un rodeo de cría con una incidencia del 5%. Los signos clínicos fueron claudicación, edema en los miembros, gangrena en las extremidades y exungulación. La pastura donde los animales permanecían correspondía a un lote naturalizado de festuca siendo el nivel de infestación con Neotyphodium coenophialum del 71%. El cuadro de pie de festuca es muy conocido pero poco informado en Argentina. En el brote el diagnostico se confirmó por los antecedentes clínicos y epidemiológicos sumado al elevado grado de infestación del hongo en la pastura. La toxicidad de la festuca es un problema mundialmente distribuido y en Argentina ha sido más estudiado en la región centro del país. Los antecedentes de toxicidad de esta especie son escasos y aislados en el Noroeste Argentino.

Festuca arundinacea is a perennial grass which use as forage is widespread worldwide. This report describes a “fescue foot” outbreak in the Northwest of Argentina. Beef cattle herd were affected and the incidence was 5%. The clinical signs were claudication, edema in the limbs, gangrene in the extremities and exungulation. The grazing areas where the animals remained corresponded to a natural batch of fescue. Neotyphodium coenophialum infestation level was 71%. The clinical presentation of fescue root is well described but barely reported in Argentina. In the outbreak presented here diagnosis was confirmed by the clinical and epidemiological antecedents as well as the high level of infestation of the pasture. The toxicity of fescue is a worldwide distributed problem. In Argentina, the disease is well known in the central region of the country. Scarce information is available regarding the toxicity of this species for northwestern Argentina.

Relationship between epigenetic marks and the behavior of 45S rDNA sites in chromosomes and interphase nuclei of Lolium-Festuca complex.

The grasses of the Lolium-Festuca complex show a prominent role in world agricultural scenario. Several studies have demonstrated that the plasticity of 45S rDNA sites has been recently associated with the possible fragility of the loci. Often, these fragile sites were observed as extended sites and gaps in metaphases. This organization can be evaluated in relation to their transcriptional activity/accessibility through epigenetic changes. Thus, this study aimed to investigate the relationship of the 5-methylcytosine and histone H3 lysine-9 dimethylation in different conformations of 45S rDNA sites in interphase nuclei and in metaphase chromosomes of L. perenne, L. multiflorum and F. arundinacea. The FISH technique using 45S rDNA probes was performed sequentially after the immunolocalization. The sites showed predominantly the following characteristics in the interphase nuclei: intra- and perinucleolar position, decondensed or partially condensed and hypomethylated and hyper/hypomethylated status. Extranucleolar sites were mainly hypermethylated for both epigenetic marks. The 45S rDNA sites with gaps identified in metaphases were always hypomethylated, which justifies it decondensed and transcriptional state. The frequency of sites with hypermethylated gaps was very low. The structural differences observed in these sites are directly related to the assessed epigenetic marks, justifying the different conformations throughout the cell cycle.

Decondensation of chromosomal 45S rDNA sites in Lolium and Festuca genotypes does not result in karyotype instability.

Fragile sites (FSs) in plants have been described for species like Lolium and other grasses. Whereas in humans FSs were shown to be involved in genome instabilities; the consequences of FSs expression in plants are not known yet. To evaluate whether FSs cause karyotype instabilities, we assessed the frequency of micronuclei and lagging chromosomes in meristematic cells, the stability of the DNA content, and the occurrence of neocentromeres in the presumed chromosomal fragments of Lolium perenne, Lolium multiflorum, Festuca arrundinacea, and two Festulolium hybrids. The cell cycle analysis along with flow cytometric genome size measurements showed high stability in all genomes evaluated. Neocentromeric activity was neither observed in the presumed fragments nor in any other chromosomal region, then this is not the mechanism responsible by the stability. However, Fluorescence in situ hybridization (FISH) with a 45S ribosomal DNA (rDNA) probe in combination with YOYO staining of metaphasic chromosomes showed that many extended nucleolus organizing region (NOR) form very thin YOYO-positive chromatin fibers connecting the acentric 'fragment' with the centromere-containing chromosome region. The obtained data indicate that the expression of FSs does not result in genome instabilities or neocentromere formation. The FS-containing 45S rDNA carrying chromatin fibers undergo a cell cycle and gene activity-dependent dynamic decondensation process.

Is the Invasive Species Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae) (Argentine Stem Weevil) a Threat to New Zealand Natural Grassland Ecosystems?

Listronotus bonariensis (Argentine stem weevil) is a stem-boring weevil that has become a major pasture pest in New Zealand, and cool climate turf grass in Australia. This species is also frequently found in native tussock grassland in New Zealand. Laboratory and field trials were established to determine the risk posed to both seedlings and established plants of three native grass species compared to what happens with a common host of this species, hybrid ryegrass (L. perenne X L. multiflorum). Adult weevil feeding damage scores were higher on Poa colensoi and Festuca novae-zelandiae than Chionochloa rigida. Oviposition was lower on P. colensoi than hybrid ryegrass, and no eggs were laid on F. novae-zelandiae. In field trials using the same four species established as spaced plants L. bonariensis laid more eggs per tiller in ryegrass in a low altitude pasture site than in ryegrass in a higher altitude site. No eggs were found on the three native grass species at the tussock sites, and only low numbers were found on other grasses at the low altitude pasture site. Despite this, numbers of adult weevils were extracted from the plants in the field trials. These may have comprised survivors of the original weevils added to the plants, together with new generation weevils that had emerged during the experiment. Irrespective, higher numbers were recovered from the tussock site plants than from those from the pasture site. It was concluded that L. bonariensis is likely to have little overall impact, but a greater impact on native grass seedling survival than on established plants.

Agricultural parameters of perennial winter grasses / Parâmetros agronômicos de gramíneas perenes de clima temperado

Introduction of forage cultivars of different countries can be an option for technology short-term transfer for access to vegetative materials for better production potential. The objective of this study was to evaluate cultivars of temperate climate perennial grasses from Uruguay and New Zealand in soil and climatic conditions in Santa Catarina State, during the years 2010 to 2012. Two simultaneous experiments were conducted, in four physiographic regions of the State: West, Midwest, South Plateau and North Plateau. In trial 1 cultivars of Lolium perenne, festulolium and oats perennial and in trial 2 cultivars of Festuca arundinaceae and dactylis were evaluated. There was interaction between cultivars and localization in both trials, during the two years of evaluation. Perennial ryegrass and festulolium significantly reduced dry matter production (DMP) over the period in the West, Midwest and Northern Plateau and it is recommended only for South Plateau region. Perennial oats may be indicated for the two regions Plateau. In trial 2, the fescue cv. Epagri 312 (control) and cv. Aurora stood out in four locations, with average values of 9 and 7 t ha-1 of dry matter, respectively for the first and second periods of evaluation.

A introdução de cultivares de forrageiras oriundas de diferentes países pode ser uma opção de transferência de tecnologia a curto prazo para acesso a materiais vegetativos de melhor potencial produtivo. O objetivo deste trabalho foi avaliar cultivares de gramíneas perenes de clima temperado provenientes do Uruguai e Nova Zelândia às condições edafoclimáticas do estado de Santa Catarina, durante os anos de 2010 a 2012. Foram conduzidos, simultaneamente, dois ensaios, em quatro regiões fisiográficas do Estado: Oeste, Meio Oeste, Planalto Sul e Planalto Norte. No ensaio 1 foram avaliados cultivares de Lolium perenne, festulolium e aveia-perene e no ensaio 2 cultivares de Festuca arundinaceae e dáctilo. Houve interação entre cultivares e locais, nos dois ensaios, nos dois anos de avaliação. Azevém-perene e festulolium reduziram significativamente a produção de massa seca (MS) ao longo do período nas regiões Oeste, Meio Oeste e Planalto Norte, sendo recomendado apenas para a região do Planalto Sul. A aveia-perene pode ser indicada para as duas regiões de Planalto, onde perenizou. No ensaio 2, as festucas cv. Epagri 312 (testemunha) e cv. Aurora destacaram-se nos quatro locais, com valores médios de 9 e 7 t ha-1 de MS, respectivamente, para o primeiro e segundo períodos de avaliação.

Agricultural parameters of perennial winter grasses / Parâmetros agronômicos de gramíneas perenes de clima temperado

Introduction of forage cultivars of different countries can be an option for technology short-term transfer for access to vegetative materials for better production potential. The objective of this study was to evaluate cultivars of temperate climate perennial grasses from Uruguay and New Zealand in soil and climatic conditions in Santa Catarina State, during the years 2010 to 2012. Two simultaneous experiments were conducted, in four physiographic regions of the State: West, Midwest, South Plateau and North Plateau. In trial 1 cultivars of Lolium perenne, festulolium and oats perennial and in trial 2 cultivars of Festuca arundinaceae and dactylis were evaluated. There was interaction between cultivars and localization in both trials, during the two years of evaluation. Perennial ryegrass and festulolium significantly reduced dry matter production (DMP) over the period in the West, Midwest and Northern Plateau and it is recommended only for South Plateau region. Perennial oats may be indicated for the two regions Plateau. In trial 2, the fescue cv. Epagri 312 (control) and cv. Aurora stood out in four locations, with average values of 9 and 7 t ha-1 of dry matter, respectively for the first and second periods of evaluation.(AU)

A introdução de cultivares de forrageiras oriundas de diferentes países pode ser uma opção de transferência de tecnologia a curto prazo para acesso a materiais vegetativos de melhor potencial produtivo. O objetivo deste trabalho foi avaliar cultivares de gramíneas perenes de clima temperado provenientes do Uruguai e Nova Zelândia às condições edafoclimáticas do estado de Santa Catarina, durante os anos de 2010 a 2012. Foram conduzidos, simultaneamente, dois ensaios, em quatro regiões fisiográficas do Estado: Oeste, Meio Oeste, Planalto Sul e Planalto Norte. No ensaio 1 foram avaliados cultivares de Lolium perenne, festulolium e aveia-perene e no ensaio 2 cultivares de Festuca arundinaceae e dáctilo. Houve interação entre cultivares e locais, nos dois ensaios, nos dois anos de avaliação. Azevém-perene e festulolium reduziram significativamente a produção de massa seca (MS) ao longo do período nas regiões Oeste, Meio Oeste e Planalto Norte, sendo recomendado apenas para a região do Planalto Sul. A aveia-perene pode ser indicada para as duas regiões de Planalto, onde perenizou. No ensaio 2, as festucas cv. Epagri 312 (testemunha) e cv. Aurora destacaram-se nos quatro locais, com valores médios de 9 e 7 t ha-1 de MS, respectivamente, para o primeiro e segundo períodos de avaliação.(AU)

CALIDAD DE LA LECHE, DIGESTIBILIDAD IN VITRO DE LA MATERIA SECA Y PRODUCCIÓN EN VACAS ALIMENTADAS CON GRAMÍNEAS SOLAS O ASOCIADAS CON Lotus uliginosus / MILK CHEMICAL COMPOSITION, MATTER DRY IN VITRO DIGESTIBILITY AND PRODUCTION IN COWS FED ALONE GRASSES OR ASSOCIATED Lotus uliginosus

La presente investigación tuvo como objetivo evaluar el uso de la leguminosa Lotus uliginosus como alternativa de inclusión dentro de las praderas en dos ecorregiones estratégicas de la Sabana de Bogotá. En cada finca se evaluaron cuatro tratamientos: 1) kikuyo solo (P. clandestinum), 2) kikuyo asociado con trébol pata de pájaro (P. clandestinum + L. uliginosus), 3) festuca alta sola (F. arundinacea) y 4) Festuca alta asociada con trébol pata de pájaro (F. arundinacea + L. uliginosus). El número de bovinos varió de acuerdo a la capacidad de carga de cada finca. Se utilizaron animales que se encontraban en el segundo tercio de lactancia durante un período experimental de siete días. En cada tratamiento se determinó la producción (L/día) y calidad de leche (% de grasa, proteína y sólidos totales); en la pastura se evaluó la composición química (MS, FDN, FDA) y la digestibilidad in vitro de la materia seca (DIVMS). Se midió el consumo voluntario. En la finca Megaleche la producción de biomasa presentó diferencias significativas (P<0,05) entre los tratamientos destacándose el tratamiento del kikuyo solo; la calidad nutricional de las pasturas también presentó diferencias (P<0,04) destacándose el tratamiento de kikuyo + trébol pata de pájaro, asociación que también se destacó en consumo voluntario (P< 0.05) y producción de leche (P<0,05). En la finca Colega el contenido de proteína del forraje presentó diferencias cuando las gramíneas se asociaron con el trébol pata de pájaro (P<0,001). Se concluyó que la introducción del Lotus en las praderas mejoró la producción de leche y consumo de materia seca en los animales.

The present research aimed to evaluate the use of the legume Lotus uliginosus alternatively inclusion into the meadows on two strategic ecoregions savannah of Bogota. In each farm four treatments: 1) only kikuyu (P. clandestinum), 2) associated kikuyo Birdsfoot trefoil (P. clandestinum + L. uliginosus), 3) single tall fescue (F. arundinacea) and 4) tall fescue associated Birdsfoot trefoil (F. arundinacea + L. uliginosus). The number of cattle varied according the load capacity of each farm. Were used animals that were in the second third of lactation during a trial period of seven days, in each treatment was determined production (L/day) and milk quality (% of fat, protein and total solids). In the pasture it was evaluated chemical composition (DM, NDF, ADF) and in vitro digestibility of matter dry (IVDMD). Voluntary intake was measured. On the farm Megaleche biomass production showed significant differences (P˂0.05) between treatments kikuyu emphasizing treatment alone nutritional quality of pastures also showed significant differences (P˂0.04) emphasizing treating kikuyu + Birdsfoot trefoil an association that was also highlighted in the voluntary intake (P˂0.05) and milk production (P˂0.05). On the farm Colega protein content of forage grasses differed when associated with Birdsfoot trefoil (P˂0.001). It was concluded that the introduction of Lotus grassland improved milk production and dry matter intake in animals.