Crop yields are coming under pressure to continue to grow in the face of climate change, competition, disease and pressure to reduce inputs. Photosynthetic efficiency is being targeted for improvement to increase yields. This study examined the variation in parameters of photosynthetic efficiency including canopy structure (leaf length, canopy angle, and chlorophyll content and growth rate) and gas exchange (photosynthetic rate, stomatal density and chlorophyll fluorescence) in Spring Barley (Hordeum vulgare ssp vulgare). These were first established for modern cultivars representing the most widely grown lines in the last 60 years. As cultivars are developed from a small pool of parents they may have limited genetic variation available for breeding. Landraces have been suggested as sources of variation. Using field and growth cabinet based studies the photosynthetic efficiencies of canopy structure and gas exchange were established for a range of European landraces under high and low nutrient inputs. This study demonstrated that in modern cultivars the leaf length increased with year of release from 23.2 to 29.6 cm and the chlorophyll content decreased from 46.9 to 34.8 SPAD units. Once the ear had emerged no difference was seen in canopy structure or photosynthetic rate. There was variation in landrace canopy establishment rate, leaf angle and number of leaves present within the canopy. The landraces from Northern European latitudes pushed though booting and reached full canopy establishment up to 8 days sooner than those from Southern Europe. This may be a response to a shorter growth season at Northern latitudes requiring the canopy to be established quickly. The landraces held the leaves within their canopy in a more horizontal position than the Southern European lines with leaf angle ranging from 18-45 degrees at GS39 and 31-84 degrees at GS59. This regressed negatively with temperature so it may be that a vertical canopy structure is beneficial in areas with higher temperatures. The photosynthetic rate of the landraces showed no variation but when chlorophyll fluorescence examined the efficiency of photosystem II (PSII) there was a positive regression of Fv/Fm ratio with latitude. This suggested that lines from Southern Europe were experiencing a greater stress with a ratio of up to 0.822 compared to those lines from the North with ratios from 0.767. The stomatal density of the landraces showed a large difference in ranges from 22-41 stomata between the lines. When high and low nutrient inputs were compared reductions from a ratio of 0.48 to 0.47 in Harvest Index and from 55g to 52g in 1000 grain weight were seen. The chlorophyll content of the lines was also reduced from 41.7 to 39.2 SPAD units at GS39 and from 44.9 to 39.8 SPAD units at GS59 by the reduction in nutrient inputs which may be a result of less N available for the production of chlorophyll. In conclusion there is variation present in canopy structure in European landraces that may be useful for future breeding or in identifying landrace collections which could be targeted for traits of interest in photosynthetic efficiency. These landraces may provide traits which could be used to develop cultivars which are locally adapted to climate and environmental conditions.

Wheat (Triticum aestivum, L) and barley (Hordeum vulgare) are widely grown as winter annual grains in a double crop rotation with soybean (Glycine max, L. Merr.) in much of the U.S. Improved management strategies and the development cultivars that meet the quality requirements of higher value end-use markets is important to increase production and profitability of winter annual grains and the double crop rotation in the Eastern U.S. In Chapter I, fifteen commercially relevant winter wheat genotypes ranging in maturity were sown in a split-plot design (sowing date=main plot, genotype=subplot) at three different sowing dates (considered to be 'very early' (20-28 days before recommended), 'early (6-11 days before recommended)', or 'recommended') and replicated three times at eight environments (site-year) from 2015-2018 in VA and KY. Grain yield, tiller estimation, heading date, protein, and 1000-kernel weight were assessed for each yield plot. At all environments, sowing earlier in the fall achieved an earlier (P<0.05) heading date, while grain yields varied depending on environment and genotype. Genotype by sowing date interactions were non-significant (P<0.05) at five site-years and significant (P<0.05) at three site-years. Molecular markers can be associated with phenotypic traits via quantitative trait loci (QTL) mapping, these markers can be used by breeders in marker assisted selection (MAS) to indirectly select phenotypic traits that are difficult or expensive to measure. In Chapter II, the genetic architecture of end-use quality is investigated in two soft red winter wheat bi-parental (Pioneer '25R47' / 'Jamestown' and Pioneer '26R46' / 'Tribute'). Both populations were genotyped with a public 90,000 wheat iSelect SNP-Array, grown over two crop seasons at two Virginia sites, evaluated for quality traits at the USDA-ARS Soft Wheat Quality Lab (SWQL), and analyzed with QTL mapping. This chapter describes a total of 24 putative QTL that were identified on 13 different chromosomes and associated with grain characteristics, milling, and/or baking performance along with phenotypic data for both populations, other putative QTL, and transgressive progeny with exceptional flour yield and cookie diameters. A region on 3A (Qfy.vt.3A.Jtwn) is a strong candidate to be utilized for MAS in soft red winter wheat breeding programs as it explained 6.9-10.3% (Pioneer 25R47 / Jamestown) and 4.6-17.0% (Pioneer 26R46 / Tribute) of the phenotypic variation for flour yield. In Chapter III, malt quality genetic structure was investigated in two winter 'malt x feed' doubled haploid barley breeding populations. Both populations were genotyped with the iSelect InfiniumTM SNP assay consisting of 50,000 barley SNPs, grown in two to three Virginia environments (Blacksburg and Warsaw) during 2017 - 2019, and characterized for 11 phenotypic traits associated with malting quality. QTL mapping validated six previously reported regions (Mohammadi, et al., 2015, GrainGenes 3.0, 2019) that are strongly associated (LOD > 3.0) with relevant malt quality traits. Phenotypic variation for malt quality was largely and consistently explained by QTL on chromosomes 1H, 5H, and 7H in the Endeavor / VA09B-34 population and by two separate QTL on 1H in the Violetta / VA09B-34 population. A region on 4H corresponding with QDp.DiMo-4H, explained between 12.1 - 42.2% (Endeavor / VA09B-34) and 30.0 - 55.7% (Violetta / VA09B-34) of the phenotypic variation for diastatic power (DU). These QTL are recommended for MAS in order to aid breeding strategies that aim to select for improved malting characteristics in Eastern U.S. malt barley breeding material. / Doctor of Philosophy / Wheat (Triticum aestivum, L) and barley (Hordeum vulgare) are staple crops throughout the world, and are the third and fourth most produced cereals crop according to the FAO. Primarily grown for human consumption, wheat and barley provide a significant percentage of the nutritional requirements for the human populations. According to the United Nations, wheat contributes 20% of all calories consumed by humans. Barley is the primary ingredient used to make beer. Increased productivity of all cropping and livestock systems is required in order to feed a growing human population while also restoring and preserving natural ecosystems. This can be accomplished through breeding and improved cropping systems management. Planting of existing cropland more frequently is fundamental to the improvement of cropping system productivity. In much of the U.S. (southern two-thirds of the lower 48), annual winter grains such as wheat and barley can be grown over the winter and spring in between the typical corn (Zea mays subsp. mays) and soybean (Glycine max, L. Merr.) growing seasons. Therefore, producing three crops in two years, as opposed to only two. Only between 6 and 11 million acres are double cropped in the US annually, for perspective, in 2018, 89 million acres of both corn and soybeans, which can only grow in summer, were planted. Over half of the soybean (~45 million) acres in Midwestern and Southeastern states could support double cropping. This is a major opportunity to maximize output per unit area, freeing up less productive land to be restored as natural ecosystems, potentially increasing carbon sequestration and species biodiversity. Winter annual grains have a very similar composition (high carbohydrate, low protein and oil) to corn, and could fill similar end-use markets currently dominated by corn (i.e. ethanol or livestock feed). For double cropping to be more widely deployed, it must be more profitable. Increased profitability of growing three crops in two years as opposed to two must outweigh the added cost of planting, managing, harvesting, and marketing the additional winter crop. Therefore, it is important to investigate management strategies that could increase production per unit area and develop new winter annual cultivars with improved end-use characteristics in order to make the winter annual more desirable to the end-users. Chapter I investigates sowing winter wheat earlier in the fall (i.e. 1st week of Oct. or last week of Sept.) in order to achieve an earlier harvest in the spring and earlier soybean planting (yield decreases 0.5 to 1 bu/ac per day that sowing is delayed), while also offering other benefits such as better-established root systems going into winter, which improves water infiltration and reduces erosion. At all environments, sowing earlier in the fall achieved an earlier heading date, while grain yields varied depending on environment and genotype. Genotype by sowing date interactions were non-significant at five site-years and significant at three site-years. Chapters II and III investigate the genetic architecture of winter wheat and winter barley breeding populations for end-use quality traits (milling/baking and malting). This was done in order to identify molecular markers that could be used to screen breeding material for improved end-use quality. The markers could then be used to assist breeders in developing soft red winter wheat cultivars with greater flour yields/improved baking performance and winter malt barley cultivars that can be grown in the Eastern U.S. and are suitable for the craft beer market. Chapter II describes 24 genomic regions that influences milling/baking performance in two soft red winter wheat breeding populations. Chapter III describes 6 genomic regions that influence malting performance in two winter barley breeding populations.

The fungal plant pathogen Fusarium graminearum Schwabe (teleomorph Gibberella zeae¬) produces a dangerous trichothecene mycotoxin called deoxynivalenol (DON) and causes a devastating disease of barley (Hordeum vulgare L.) called Fusarium head blight (FHB). Food and feed products derived from barley, such as dried distillers grains with solubles (DDGS), may be contaminated with DON and pose a threat to the health of humans and domestic animals. New methods to mitigate the threat of DON in barley need to be developed and implemented. TRI101 and TRI201 are trichothecene 3-O-acetyltransferases that modify DON and reduce its toxicity. The first objective of this research was to isolate unique TRI101 and TRI201 enzymes that modify DON efficiently. We hypothesized that TRI101/TRI201 enzymes from different species of Fusarium would have varying rates and abilities to modify DON. Using degenerate primers, an internal portion of TRI101 or TRI201 was identified in 54 strains of Fusarium. Full-length sequences of seven TRI101 or TRI201 genes were cloned and expressed in yeast. All seven genes acetylated DON, but at different rates. The second objective of this research was to utilize transformed yeast expressing TRI101 or TRI201 to reduce DON levels in barley mashes and ultimately in DDGS. We hypothesized that DON levels would be reduced in DDGS derived from mashes prepared with transformed yeast. Five different barley genotypes were used to prepare the fermentation mashes and DON levels were reduced in all DDGS samples derived from mashes prepared with transformed yeast. The third objective of this study was to characterize barley genotypes developed at Virginia Tech for resistance to FHB and DON. We hypothesized that significant differences in resistance would be observed among barley genotypes and FHB resistance would be associated with reduced DON accumulation. From 2006 to 2010, FHB resistance was assessed in hulled (22 to 37) and hulless (13 to 32) barley genotypes by measuring incidence and index, and DON resistance was determined by quantifying DON levels in ground grain using gas chromatography-mass spectrometry. Our study showed that FHB and DON resistance is significantly determined by genotype. The final objective of this study was to develop a robust tissue culture system necessary for future development of transformed barley plants with FHB resistance gene(s). We hypothesized that callus production would vary among barley genotypes. In our analysis of 47 Virginia barley genotypes, 76% (36/47) of the genotypes produced callus tissue and there were significant differences in callus size. Our work sets the stage for identifying and characterizing DON detoxification genes in the future. The development of commercial barley lines that do not accumulate DON and that are resistant to FHB will directly impact growers and producers of small grains in the eastern U.S. / Ph. D.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

A presente Tese de Doutorado objetivou: (1) definir um método eficiente de transformação genética, por bombardeamento de partículas, para a obtenção de plantas transgênicas de cultivares brasileiras de cevada e (2) identificar gene(s) codificante(s) de quitinase(s) potencialmente capaz(es) de conferir resistência ao fungo patogênico de cevada Bipolaris sorokiniana. Culturas de calos obtidos a partir de escutelos imaturos das cultivares Brasileiras de cevada MN-599 e MN-698 (Cia. de Bebidas das Américas, AMBEV) foram bombardeadas com partículas de tungstênio e avaliadas quanto à expressão do gene repórter gusA através de ensaios histoquímicos de GUS e quanto ao efeito dos bombardeamentos na indução estruturas embriogênicas e regeneração de plantas. As condições de biobalística analisadas incluíram a região promotora regulando a expressão de gusA, tipo e pressão de gás hélio de dois aparelhos de bombardeamento, distância de migração das partículas, número de tiros e a realização de pré e pós-tratamento osmótico dos tecidos-alvo. No presente trabalho foram obtidos um número bastante alto de pontos azuis por calo, a indução de calos embriogênicos e embriões somáticos em uma freqüência de até 58,3% e a regeneração de 60 plantas, sendo 43 de calos bombardeados. As melhores condições observadas foram o promotor e primeiro íntron do gene Adh de milho (plasmídeo pNGI), o aparelho de bombardeamento “ Particle Inflow Gun” (PIG) utilizando-se a distância de migração de partículas de 14,8 cm, dois tiros disparados por placa e a realização de tratamento osmótico dos explantes com 0,2 M de manitol e 0,2 M de sorbitol 4-5 horas antes e 17-19 horas depois dos bombardeamentos. Das 43 plantas obtidas de calos bombardeadas, 3 apresentaram atividade de GUS na base das suas folhas. A utilização de primers sintéticos definidos a partir de genes de quitinases descritos na literatura em PCRs resultou na amplificação de dois fragmentos de aproximadamente 700 e 500 pb a partir de DNA total das cvs. MN-599 e MN-698 de cevada e um fragmento, com aproximadamente 500 pb, a partir do DNA total do isolado A4c de Trichoderma sp. Estes fragmentos foram purificados dos géis de agarose e diretamente seqüenciados de forma manual e automática. Os fragmentos de 700 e 500 pb amplificados do genoma da cultivar MN-599 foram identificados como genes de quitinases de cevada e o fragmento de 500 pb do isolado A4c de Trichoderma sp. não apresentou homologia com seqüências conhecidas de quitinases depositadas no EMBL/GenBank. A utilização de novos pares de primers, representando seqüências conservadas de quitinases do fungo Metarhizium anisopliae, resultou na amplificação de 3 fragmentos a partir do DNA total do isolado A4b de Trichoderma sp., que estão sendo purificados para realização de seqüenciamento. / The present Tesis aimed: (1) to determine an efficient method of genetic transformation by particle bombardment to obtain transgenic plants of Brazilian barley cultivars and (2) to identify a gene coding for chitinase that could confer resistance to barley against the pathogen Bipolaris sorokiniana. Calli cultures derived from immature scutella of Brazilian barley cultivars MN-599 e MN-698 (American Beverage Company, AMBEV) were bombarded with tungsten particles and analyzed for gusA reporter gene expression by GUS histochemical assay, embryogenic structures induction and plant regeneration. Physical and biological biolistic conditions analyzed included two promoter regions regulating the gusA gene, two particle bombardment devices, different helium pressures, distances between target tissues and the initial position of particles, number of shots and use of osmotic pre- and post-treatment of tissues. In the present work there were observed high numbers of blue spots per callus, embryogenic calli and somatic embryos induction with a frequency until 58.3% and the regeneration of 60 plants, being 43 from bombarded calli. The best conditions were obtained with the employment of the Adh promoter and its first intron (pNGI plasmid), Particle Inflow Gun (PIG) device, 14.8 cm of distance, 2 shots per plate and osmotic treatment of tissues with 0.2 M mannitol and 0.2 M sorbitol during 4-5 hours prior to and 17-19 hours after bombardments. Leaves from 3 out of 43 regenerated plants showed positive GUS activity in histochemical assays. The use of primers defined from chitinase genes described in literature resulted in the amplification of two fragments with approximately 700 and 500 bp from genomic DNA of MN-599 e MN-698 barley cultivars and one fragment, with approximately 500 bp, from Trichoderma sp. strain A4c genomic DNA. These fragments were purified from agarose gel and manual and automatically sequenced. Fragments of 700 and 500 bp from cv. MN-599 were identified as chitinase genes of barley and fragment of 500 bp Trichoderma sp. A4c presented no homology with chitinase sequences deposited in the EMBL/GenBank. The use of new primers representing conserved chitinase sequences of Metarhizium anisopliae resulted in the amplification of three fragments from genomic DNA of Trichoderma sp. strain A4b. These fragments should be purified and sequenced

A presente Tese de Doutorado objetivou: (1) definir um método eficiente de transformação genética, por bombardeamento de partículas, para a obtenção de plantas transgênicas de cultivares brasileiras de cevada e (2) identificar gene(s) codificante(s) de quitinase(s) potencialmente capaz(es) de conferir resistência ao fungo patogênico de cevada Bipolaris sorokiniana. Culturas de calos obtidos a partir de escutelos imaturos das cultivares Brasileiras de cevada MN-599 e MN-698 (Cia. de Bebidas das Américas, AMBEV) foram bombardeadas com partículas de tungstênio e avaliadas quanto à expressão do gene repórter gusA através de ensaios histoquímicos de GUS e quanto ao efeito dos bombardeamentos na indução estruturas embriogênicas e regeneração de plantas. As condições de biobalística analisadas incluíram a região promotora regulando a expressão de gusA, tipo e pressão de gás hélio de dois aparelhos de bombardeamento, distância de migração das partículas, número de tiros e a realização de pré e pós-tratamento osmótico dos tecidos-alvo. No presente trabalho foram obtidos um número bastante alto de pontos azuis por calo, a indução de calos embriogênicos e embriões somáticos em uma freqüência de até 58,3% e a regeneração de 60 plantas, sendo 43 de calos bombardeados. As melhores condições observadas foram o promotor e primeiro íntron do gene Adh de milho (plasmídeo pNGI), o aparelho de bombardeamento “ Particle Inflow Gun” (PIG) utilizando-se a distância de migração de partículas de 14,8 cm, dois tiros disparados por placa e a realização de tratamento osmótico dos explantes com 0,2 M de manitol e 0,2 M de sorbitol 4-5 horas antes e 17-19 horas depois dos bombardeamentos. Das 43 plantas obtidas de calos bombardeadas, 3 apresentaram atividade de GUS na base das suas folhas. A utilização de primers sintéticos definidos a partir de genes de quitinases descritos na literatura em PCRs resultou na amplificação de dois fragmentos de aproximadamente 700 e 500 pb a partir de DNA total das cvs. MN-599 e MN-698 de cevada e um fragmento, com aproximadamente 500 pb, a partir do DNA total do isolado A4c de Trichoderma sp. Estes fragmentos foram purificados dos géis de agarose e diretamente seqüenciados de forma manual e automática. Os fragmentos de 700 e 500 pb amplificados do genoma da cultivar MN-599 foram identificados como genes de quitinases de cevada e o fragmento de 500 pb do isolado A4c de Trichoderma sp. não apresentou homologia com seqüências conhecidas de quitinases depositadas no EMBL/GenBank. A utilização de novos pares de primers, representando seqüências conservadas de quitinases do fungo Metarhizium anisopliae, resultou na amplificação de 3 fragmentos a partir do DNA total do isolado A4b de Trichoderma sp., que estão sendo purificados para realização de seqüenciamento. / The present Tesis aimed: (1) to determine an efficient method of genetic transformation by particle bombardment to obtain transgenic plants of Brazilian barley cultivars and (2) to identify a gene coding for chitinase that could confer resistance to barley against the pathogen Bipolaris sorokiniana. Calli cultures derived from immature scutella of Brazilian barley cultivars MN-599 e MN-698 (American Beverage Company, AMBEV) were bombarded with tungsten particles and analyzed for gusA reporter gene expression by GUS histochemical assay, embryogenic structures induction and plant regeneration. Physical and biological biolistic conditions analyzed included two promoter regions regulating the gusA gene, two particle bombardment devices, different helium pressures, distances between target tissues and the initial position of particles, number of shots and use of osmotic pre- and post-treatment of tissues. In the present work there were observed high numbers of blue spots per callus, embryogenic calli and somatic embryos induction with a frequency until 58.3% and the regeneration of 60 plants, being 43 from bombarded calli. The best conditions were obtained with the employment of the Adh promoter and its first intron (pNGI plasmid), Particle Inflow Gun (PIG) device, 14.8 cm of distance, 2 shots per plate and osmotic treatment of tissues with 0.2 M mannitol and 0.2 M sorbitol during 4-5 hours prior to and 17-19 hours after bombardments. Leaves from 3 out of 43 regenerated plants showed positive GUS activity in histochemical assays. The use of primers defined from chitinase genes described in literature resulted in the amplification of two fragments with approximately 700 and 500 bp from genomic DNA of MN-599 e MN-698 barley cultivars and one fragment, with approximately 500 bp, from Trichoderma sp. strain A4c genomic DNA. These fragments were purified from agarose gel and manual and automatically sequenced. Fragments of 700 and 500 bp from cv. MN-599 were identified as chitinase genes of barley and fragment of 500 bp Trichoderma sp. A4c presented no homology with chitinase sequences deposited in the EMBL/GenBank. The use of new primers representing conserved chitinase sequences of Metarhizium anisopliae resulted in the amplification of three fragments from genomic DNA of Trichoderma sp. strain A4b. These fragments should be purified and sequenced

It was carried an experiment, in the Fitotecnia Department of the Federal University of Santa Maria (UFSM) - RS, with objective to evaluate the nutritional quality of two species of grassy (Hordeum vulgare L. and Secale cereale L.), cultivated in hydroponic, during of autumn and winter and to evaluate the nutritional quality of two species of grassy (Hordeum vulgare L. and Secale cereale L) joined to a legume (Vicia sativa L.), cultivated in hydroponic, during autumn and winter. It was adopted the experimental delineation entirely casuistic with four repetitions. The data had been submitted to the variance analysis. The averages of the qualitative variables had been compared among themselves for Tukey test with 5% of error probability. The hydroponic Secale cereale L forage showed bigger dry mass and mineral substance in autumn and winter, surpassing the Hordeum vulgare L forage, Hordeum vulgare L.: intercropping+Vicia sativa L and Secale cereale L+Vicia sativa L. Hydroponic Secale cereale L forage intercropping+Vicia sativa L 150 presented bigger dry mass than the others treatments, however, the mineral substance resulted in minors values, what negatively differentiated in relation the Secale cereale L forage. The biggest fiber value in neutral detergent found, was in the hydroponic Hordeum vulgare L. forage, although it did not show significant difference in relation to the others treatments. The hydroponic Secale cereale L forage presented a bigger rude protein value in relation to the others treatments. The hydroponic forages it did not show significant difference in relation to energetic value and value of phosphorus. The biggest value of calcium and magnesium had been found in the hydroponic Secale cereale L. forage. The Hordeum vulgare L. produced in the 2002 winter, presented minors potassium value, differing significantly from the Hordeum vulgare L intercropping + Vicia sativa L 300 and Secale cereale L + Vicia sativa L 150. / Foi realizado um experimento, no Departamento de Fitotecnia da Universidade Federal de Santa Maria (UFSM) RS, com objetivo de avaliar a qualidade nutricional de duas espécies de gramíneas (cevada e centeio), cultivadas em hidroponia, no período de outono e inverno e avaliar a qualidade nutricional de duas espécies de gramíneas (cevada e centeio) consorciadas a uma leguminosa (ervilhaca), cultivadas em hidroponia, no período de outono e inverno. Adotou-se o delineamento experimental inteiramente casualizado com quatro repetições. Os dados obtidos foram submetidos à análise de variância. As médias das variáveis qualitativas foram comparadas entre si pelo teste de Tukey a 5% de probabilidade de erro.A forragem hidropônica de centeio apresentou maior massa seca e matéria mineral no outono e inverno, superando a forragem de cevada, consórcio de cevada + ervilhaca e centeio + ervilhaca. O consórcio de forragem hidropônica de centeio + ervilhaca 150 apresentou maior massa seca que os demais tratamentos consorciados, entretanto, a matéria mineral resultou em menores valores, o que diferenciou negativamente em relação à forragem de centeio. O maior teor de fibra em detergente neutro (FDN) encontrado, foi na forragem hidropônica de cevada, apesar de não ter apresentado diferença significativa em relação aos demais tratamentos. A forragem hidropônica de centeio apresentou um maior teor de proteína bruta em relação aos demais tratamentos. As forragens hidropônicas não apresentaram diferença significativa para o valor energético e o teor de fósforo. Os maiores teores de cálcio e magnésio foram encontrados na forragem hidropônica de centeio. A cevada produzida no inverno de 2002 apresentou menores teores de potássio, diferindo significativamente do consórcio de cevada + ervilhaca 300 e centeio + ervilhaca 150.

A presente Tese de Doutorado objetivou: (1) definir um método eficiente de transformação genética, por bombardeamento de partículas, para a obtenção de plantas transgênicas de cultivares brasileiras de cevada e (2) identificar gene(s) codificante(s) de quitinase(s) potencialmente capaz(es) de conferir resistência ao fungo patogênico de cevada Bipolaris sorokiniana. Culturas de calos obtidos a partir de escutelos imaturos das cultivares Brasileiras de cevada MN-599 e MN-698 (Cia. de Bebidas das Américas, AMBEV) foram bombardeadas com partículas de tungstênio e avaliadas quanto à expressão do gene repórter gusA através de ensaios histoquímicos de GUS e quanto ao efeito dos bombardeamentos na indução estruturas embriogênicas e regeneração de plantas. As condições de biobalística analisadas incluíram a região promotora regulando a expressão de gusA, tipo e pressão de gás hélio de dois aparelhos de bombardeamento, distância de migração das partículas, número de tiros e a realização de pré e pós-tratamento osmótico dos tecidos-alvo. No presente trabalho foram obtidos um número bastante alto de pontos azuis por calo, a indução de calos embriogênicos e embriões somáticos em uma freqüência de até 58,3% e a regeneração de 60 plantas, sendo 43 de calos bombardeados. As melhores condições observadas foram o promotor e primeiro íntron do gene Adh de milho (plasmídeo pNGI), o aparelho de bombardeamento “ Particle Inflow Gun” (PIG) utilizando-se a distância de migração de partículas de 14,8 cm, dois tiros disparados por placa e a realização de tratamento osmótico dos explantes com 0,2 M de manitol e 0,2 M de sorbitol 4-5 horas antes e 17-19 horas depois dos bombardeamentos. Das 43 plantas obtidas de calos bombardeadas, 3 apresentaram atividade de GUS na base das suas folhas. A utilização de primers sintéticos definidos a partir de genes de quitinases descritos na literatura em PCRs resultou na amplificação de dois fragmentos de aproximadamente 700 e 500 pb a partir de DNA total das cvs. MN-599 e MN-698 de cevada e um fragmento, com aproximadamente 500 pb, a partir do DNA total do isolado A4c de Trichoderma sp. Estes fragmentos foram purificados dos géis de agarose e diretamente seqüenciados de forma manual e automática. Os fragmentos de 700 e 500 pb amplificados do genoma da cultivar MN-599 foram identificados como genes de quitinases de cevada e o fragmento de 500 pb do isolado A4c de Trichoderma sp. não apresentou homologia com seqüências conhecidas de quitinases depositadas no EMBL/GenBank. A utilização de novos pares de primers, representando seqüências conservadas de quitinases do fungo Metarhizium anisopliae, resultou na amplificação de 3 fragmentos a partir do DNA total do isolado A4b de Trichoderma sp., que estão sendo purificados para realização de seqüenciamento. / The present Tesis aimed: (1) to determine an efficient method of genetic transformation by particle bombardment to obtain transgenic plants of Brazilian barley cultivars and (2) to identify a gene coding for chitinase that could confer resistance to barley against the pathogen Bipolaris sorokiniana. Calli cultures derived from immature scutella of Brazilian barley cultivars MN-599 e MN-698 (American Beverage Company, AMBEV) were bombarded with tungsten particles and analyzed for gusA reporter gene expression by GUS histochemical assay, embryogenic structures induction and plant regeneration. Physical and biological biolistic conditions analyzed included two promoter regions regulating the gusA gene, two particle bombardment devices, different helium pressures, distances between target tissues and the initial position of particles, number of shots and use of osmotic pre- and post-treatment of tissues. In the present work there were observed high numbers of blue spots per callus, embryogenic calli and somatic embryos induction with a frequency until 58.3% and the regeneration of 60 plants, being 43 from bombarded calli. The best conditions were obtained with the employment of the Adh promoter and its first intron (pNGI plasmid), Particle Inflow Gun (PIG) device, 14.8 cm of distance, 2 shots per plate and osmotic treatment of tissues with 0.2 M mannitol and 0.2 M sorbitol during 4-5 hours prior to and 17-19 hours after bombardments. Leaves from 3 out of 43 regenerated plants showed positive GUS activity in histochemical assays. The use of primers defined from chitinase genes described in literature resulted in the amplification of two fragments with approximately 700 and 500 bp from genomic DNA of MN-599 e MN-698 barley cultivars and one fragment, with approximately 500 bp, from Trichoderma sp. strain A4c genomic DNA. These fragments were purified from agarose gel and manual and automatically sequenced. Fragments of 700 and 500 bp from cv. MN-599 were identified as chitinase genes of barley and fragment of 500 bp Trichoderma sp. A4c presented no homology with chitinase sequences deposited in the EMBL/GenBank. The use of new primers representing conserved chitinase sequences of Metarhizium anisopliae resulted in the amplification of three fragments from genomic DNA of Trichoderma sp. strain A4b. These fragments should be purified and sequenced

It was carried an experiment, in the Fitotecnia Department of the Federal University of Santa Maria (UFSM) - RS, with objective to evaluate the nutritional quality of two species of grassy (Hordeum vulgare L. and Secale cereale L.), cultivated in hydroponic, during of autumn and winter and to evaluate the nutritional quality of two species of grassy (Hordeum vulgare L. and Secale cereale L) joined to a legume (Vicia sativa L.), cultivated in hydroponic, during autumn and winter. It was adopted the experimental delineation entirely casuistic with four repetitions. The data had been submitted to the variance analysis. The averages of the qualitative variables had been compared among themselves for Tukey test with 5% of error probability. The hydroponic Secale cereale L forage showed bigger dry mass and mineral substance in autumn and winter, surpassing the Hordeum vulgare L forage, Hordeum vulgare L.: intercropping+Vicia sativa L and Secale cereale L+Vicia sativa L. Hydroponic Secale cereale L forage intercropping+Vicia sativa L 150 presented bigger dry mass than the others treatments, however, the mineral substance resulted in minors values, what negatively differentiated in relation the Secale cereale L forage. The biggest fiber value in neutral detergent found, was in the hydroponic Hordeum vulgare L. forage, although it did not show significant difference in relation to the others treatments. The hydroponic Secale cereale L forage presented a bigger rude protein value in relation to the others treatments. The hydroponic forages it did not show significant difference in relation to energetic value and value of phosphorus. The biggest value of calcium and magnesium had been found in the hydroponic Secale cereale L. forage. The Hordeum vulgare L. produced in the 2002 winter, presented minors potassium value, differing significantly from the Hordeum vulgare L intercropping + Vicia sativa L 300 and Secale cereale L + Vicia sativa L 150. / Foi realizado um experimento, no Departamento de Fitotecnia da Universidade Federal de Santa Maria (UFSM) RS, com objetivo de avaliar a qualidade nutricional de duas espécies de gramíneas (cevada e centeio), cultivadas em hidroponia, no período de outono e inverno e avaliar a qualidade nutricional de duas espécies de gramíneas (cevada e centeio) consorciadas a uma leguminosa (ervilhaca), cultivadas em hidroponia, no período de outono e inverno. Adotou-se o delineamento experimental inteiramente casualizado com quatro repetições. Os dados obtidos foram submetidos à análise de variância. As médias das variáveis qualitativas foram comparadas entre si pelo teste de Tukey a 5% de probabilidade de erro.A forragem hidropônica de centeio apresentou maior massa seca e matéria mineral no outono e inverno, superando a forragem de cevada, consórcio de cevada + ervilhaca e centeio + ervilhaca. O consórcio de forragem hidropônica de centeio + ervilhaca 150 apresentou maior massa seca que os demais tratamentos consorciados, entretanto, a matéria mineral resultou em menores valores, o que diferenciou negativamente em relação à forragem de centeio. O maior teor de fibra em detergente neutro (FDN) encontrado, foi na forragem hidropônica de cevada, apesar de não ter apresentado diferença significativa em relação aos demais tratamentos. A forragem hidropônica de centeio apresentou um maior teor de proteína bruta em relação aos demais tratamentos. As forragens hidropônicas não apresentaram diferença significativa para o valor energético e o teor de fósforo. Os maiores teores de cálcio e magnésio foram encontrados na forragem hidropônica de centeio. A cevada produzida no inverno de 2002 apresentou menores teores de potássio, diferindo significativamente do consórcio de cevada + ervilhaca 300 e centeio + ervilhaca 150.