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Made available in DSpace on 2022-05-10T15:13:56Z (GMT). No. of bitstreams: 1 Ok-Silva-et-al-2022a.pdf: 525666 bytes, checksum: 9d54e1d6e49240a94bb40551bd92aa39 (MD5) Previous issue date: 2022

RNA-seq is a technique based on the large-scale sequencing of transcript-derived cDNAs using next-generation sequencing platforms mostly used today to characterize an organism?s transcriptome. The analysis of RNA-seq data allows for identifying genes differentially expressed in a given condition, such as salt stress. This study aimed to search and characterize genes from the African oil palm (Elaeis guineensis Jacq.) highly up-regulated during salt stress, with a long-term goal of gene promoter prospection and validation. The apical leaves from the control (electrical conductivity of ~2 dS m-1) and salt-stressed (~40 dS m-1) young oil palm plants, collected at 5 and 12 days after the beginning of the stress, were subjected to extraction of total RNA, with three plants (replicates) per treatment. The complete genome of E. guineensis, available at the National Center for Biotechnology Information, was used as the reference genome - BioProject PRJNA192219. The differential expression analysis led to the selection for further characterization of seven genes, which had increased expressions of 37?84 times under salt stress. The strategy used in this study enabled the selection of seven salt-responsive genes highly up-regulated during salt stress, and some of them coded for proteins already reported as responsible for salinity tolerance in other plant species through over-expression or knockout. Resumo: O RNA-seq é uma técnica baseada no sequenciamento em larga escala de cDNAs derivados de transcritos - por meio de plataformas de sequenciamento de nova geração ? amplamente utilizada atualmente para caracterizar o transcriptoma de um organismo. A análise dos dados de RNA-seq permite identificar genes diferencialmente expressos em uma determinada condição, como o estresse salino. Este estudo teve como objetivo prospectar genes do dendê (Elaeis guineensis) responsivos ao estresse salino e realizar sua caracterização funcional e estrutural. A folha apical de plantas jovens de dendê controle (condutividade elétrica de ~2 dS m-1) e estressadas (~40 dS m-1), coletadas aos 5 e 12 dias após o início do estresse, foi submetida à extração de RNA total, com três plantas (repetições) por tratamento. O genoma completo de E. guineensis, disponível no ?National Center for Biotechnology Information?, foi utilizado como genoma de referência - BioProject PRJNA192219. A análise da expressão diferencial levou à seleção de sete genes, cujo nível de expressão aumentou entre 37 e 84 vezes sob estresse salino, para posterior caracterização. A estratégia utilizada neste estudo permitiu a seleção de sete genes responsivos ao sal suprarregulados durante o estresse, e alguns deles codificam proteínas já relatadas como responsáveis pela tolerância à salinidade em outras espécies de plantas por superexpressão ou knock-out. Made available in DSpace on 2021-09-03T02:14:51Z (GMT). No. of bitstreams: 1 Genes-highly-overexpressed-in-salt-stressed-2021.pdf: 1730175 bytes, checksum: dada6d7030002fc41f5fe64eb8767cb7 (MD5) Previous issue date: 2021 Título em português: Genes altamente superexpressos em dendezeiros jovens (Elaeis guineensis) estressados por sal.

Oil palm (Elaeis guineensis Jacq.) is the number one source of consumed vegetable oil nowadays. It is cultivated in areas of tropical rainforest, where it meets its natural condition of high rainfall throughout the year. The palm oil industry faces criticism due to a series of practices that was considered not environmentally sustainable, and it finds itself under pressure to adopt new and innovative procedures to reverse this negative public perception. Cultivating this oilseed crop outside the rainforest zone is only possible using artificial irrigation. Close to 30% of the world?s irrigated agricultural lands also face problems due to salinity stress. Consequently, the research community must consider drought and salinity together when studying to empower breeding programs in order to develop superior genotypes adapted to those potential new areas for oil palm cultivation. Multi-Omics Integration (MOI) offers a new window of opportunity for the non-trivial challenge of unraveling the mechanisms behind multigenic traits, such as drought and salinity tolerance. The current study carried out a comprehensive, large-scale, single-omics analysis (SOA), and MOI study on the leaves of young oil palm plants submitted to very high salinity stress. Taken together, a total of 1239 proteins were positively regulated, and 1660 were negatively regulated in transcriptomics and proteomics analyses. Meanwhile, the metabolomics analysis revealed 37 metabolites that were upregulated and 92 that were downregulated. After performing SOA, 436 differentially expressed (DE) full-length transcripts, 74 DE proteins, and 19 DE metabolites ffected by this stress, with at least one DE molecule in all three omics platforms used. The Cysteine and methionine metabolism (map00270) and Glycolysis/Gluconeogenesis (map00010) pathways were the most affected ones, each one with 20 DE molecules. Made available in DSpace on 2022-07-21T21:19:21Z (GMT). No. of bitstreams: 1 MANOEL-SEG-12.15.00.007.00.19-Bittencourt-et-al-2022.pdf: 1200431 bytes, checksum: 1f3cc8d002f49f567e552647f4a276c2 (MD5) Previous issue date: 2022

Soil salinity is among the abiotic stressors that threaten agriculture the most, and purslane (Portulaca oleracea L.) is a dicot species adapted to inland salt desert and saline habitats that hyper accumulates salt and has high phytoremediation potential. Many researchers consider purslane a suitable model species to study the mechanisms of plant tolerance to drought and salt stresses. Here, a robust salinity stress protocol was developed and used to characterize the morphophysiological responses of young purslane plants to salinity stress; then, leaf tissue underwent characterization by distinct omics platforms to gain further insights into its response to very high salinity stress. Made available in DSpace on 2022-08-03T18:20:11Z (GMT). No. of bitstreams: 1 MultiOmicsAnalysisYoungPortulacaOleraceaPhenomicsMay2022-1.pdf: 4498228 bytes, checksum: 77fe4cd278d99512e68cb62e794641e3 (MD5) Previous issue date: 2022 Published online: 15 June 2022.

The multipurpose tree Gliricidia sepium (Jacq.) Walp. adapts to a very high level of salt stress (≥20 dS m-1) and resumes the production of new leaves around 2 weeks after losing all leaves due to abrupt salinity stress. The integration of metabolome and transcriptome profiles from gliricidia leaves points to a central role of the phenylpropanoid biosynthesis pathway in the short-term response to salinity stress. In this study, a deeper untargeted metabolomics analysis of the leaves and roots of young gliricidia plants was conducted to characterize the mechanism(s) behind this adaptation response. The polar and lipidic fractions from leaf and root samples were extracted and analyzed on a UHPLC.ESI.Q-TOF.HRMS system. Made available in DSpace on 2022-08-03T19:19:57Z (GMT). No. of bitstreams: 1 DeepUntargetedMetabolomicsAnalysisFurtherCharacterizeFPSMay2022.pdf: 2979305 bytes, checksum: 52bbd7802dc3109018e9e514eca7d101 (MD5) Previous issue date: 2022

The objective of this work was to determine the suitability of Setaria viridis as a model plant in studies to validate candidate genes for cold tolerance by evaluating the response of two of its accessions to different durations of abrupt or gradual cold stress in the vegetative and reproductive stages. Plants of accessions A10.1 and Ast-1, cultivated at 25°C, were subjected to the following cold stress treatments: gradual reduction in temperature from 25 to 0°C, 5°C at a time, every 24 hours in a same chamber; or abrupt reduction in temperature, by transferring plants from a chamber at 25°C to another at 0°C. Plants were kept at 0°C for 3, 5, or 10 days, after which temperature was increased back again to 25°C; a control group remained at 25ºC. Low temperatures ? reduced abruptly or gradually ? caused a decrease in the gas exchange rates and shoot and root biomass of the plants, besides damage to their photochemical apparatus; the longer the cold lasted, the more pronounced the effect was. Regardless of stress duration, plants recovered and completed their life cycle. The studied accessions are tolerant to cold and, therefore, are not suitable as a model plant in studies to validate candidate genes for cold tolerance. RESUMO - O objetivo deste trabalho foi determinar a adequação de Setaria viridis como planta modelo em estudos de validação de genes candidatos à tolerância ao frio, ao avaliar a resposta de dois de seus acessos a diferentes durações de estresse por frio abrupto ou gradual, nas fases vegetativa e reprodutiva. Plantas dos acessos A10.1 e Ast-1, cultivadas a 25°C, foram submetidas aos seguintes tratamentos de estresse por frio: redução gradual da temperatura de 25 a 0°C, 5°C de cada vez, a cada 24 horas, em única câmera; ou redução abrupta da temperatura, pela transferência das plantas de uma câmera a 25°C para outra a 0°C. As plantas foram mantidas a 0°C por 3, 5, ou 10 dias, após os quais a temperatura foi aumentada novamente para 25°C; um grupo controle permaneceu a 25ºC. As baixas temperaturas ? reduzidas gradual ou abruptamente ? causaram redução nas taxas de troca gasosa e na biomassa da parte aérea e da raiz das plantas, além de prejuízos ao seu aparato fotoquímico; quanto mais o frio durou, mais pronunciado o efeito foi. Independentemente da duração do estresse, as plantas se recuperaram e completaram seu ciclo de vida. Os acessos estudados são tolerantes ao frio, e, portanto, não são adequados como planta modelo em estudos para validação de genes candidatos de tolerância ao frio. Made available in DSpace on 2022-08-24T21:19:20Z (GMT). No. of bitstreams: 1 Morphophysiological-responses-setaria-2022.pdf: 1453393 bytes, checksum: 28a0992083088417db452cbc19ef5659 (MD5) Previous issue date: 2022 Título em português: Respostas morfofisiológicas de Setaria viridis ao estresse por frio.

The expansion of the oil palm in marginal areas can face challenges, such as water deficit, leading to an impact on palm oil production. A better understanding of the biological consequences of abiotic stresses on this crop can result from joint metabolic profiling and multivariate analysis. Metabolic profiling of leaves was performed from control and stressed plants (7 and 14 days of stress). Samples were extracted and analyzed on a UHPLC-ESI-Q-TOF-HRMS system. Acquired data were processed using XCMS Online and MetaboAnalyst for multivariate and pathway activity analysis. Metabolism was affected by drought stress through clear segregation between control and stressed groups. More importantly, metabolism changed through time, gradually from 7 to 14 days. The pathways most affected by drought stress were: starch and sucrose metabolism, glyoxylate and dicarboxylate metabolism, alanine, aspartate and glutamate metabolism, arginine and proline metabolism, and glycine, serine and threonine metabolism. The analysis of the metabolic profile were efficient to correlate and differentiate groups of oil palm plants submitted to different levels of drought stress. Putative compounds and their affected pathways can be used in future multiomics analysis. Made available in DSpace on 2021-09-15T02:19:12Z (GMT). No. of bitstreams: 1 Metabolic-effect-of-drought-stress-2021.pdf: 3072728 bytes, checksum: 8a08dc036a6427440dc459d86e9041c9 (MD5) Previous issue date: 2021 Nature Portfolio.

Soil salinity is one abiotic stress that threatens agriculture in more than 100 countries. Gliricidia [Gliricidia sepium (Jacq.) Kunth] is a multipurpose tree known for its ability to adapt to a wide range of soils; however, its tolerance limits and responses to salt stress are not yet well understood. In this study, after characterizing the morphophysiological responses of young gliricidia plants to salinity stress, leaf metabolic and transcription profiles were generated and submitted to single and integrated analyses. RNA from leaf samples were subjected to RNA sequencing using an Illumina HiSeq platform and the paired-end strategy. Polar and lipidic fractions from leaf samples were extracted and analyzed on an ultra-high-performance liquid chromatography (UHPLC) coupled with electrospray ionization quadrupole time-offlight high-resolution mass spectrometry (MS) system. Acquired data were analyzed using the OmicsBox, XCMS Online, MetaboAnalyst, and Omics Fusion platforms. The substrate salinization protocol used allowed the identification of two distinct responses to salt stress: tolerance and adaptation. Single analysis on transcriptome and metabolome data sets led to a group of 5,672 transcripts and 107 metabolites differentially expressed in gliricidia leaves under salt stress. The phenylpropanoid biosynthesis was the most affected pathway, with 15 metabolites and three genes differentially expressed. Results showed that the differentially expressed metabolites and genes from this pathway affect mainly short-term salt stress (STS). The single analysis of the transcriptome identified 12 genes coding for proteins that might play a role in gliricidia response at both STS and long-termsalt stress (LTS). Further studies are needed to reveal the mechanisms behind the adaptation response. Made available in DSpace on 2022-01-26T16:01:29Z (GMT). No. of bitstreams: 1 The-Plant-Genome-2022-Integration.pdf: 1821768 bytes, checksum: b38c5e117bd751a9000778024d4b2222 (MD5) Previous issue date: 2021

Setaria viridis (L.) P. Beauv. is a species proposed to be used as model plant in reverse genetics studies for the validation of gene function. Soil salinity is a recurring problem present in more than a 100 countries worldwide, and approximately 20% of the agricultural land in the world has saline and/or sodium soils. Saline stress affects all the main processes of the plant, such as germination, growth, and, consequently, the yield. The present study aimed at determining the tolerance levels of S. viridis A10.1 to saline stress and identify its potential as a model plant to validate salt-tolerance candidate genes/alleles as well as promoter sequences from salt-responsive genes. In an initial experiment, the seeds of the plant were sown on a germination medium containing an increasing concentration of NaCl (0, 30, 60, 90, 120, or 150 mM), and maintained there during the initial growth stage; and, in another experiment, the plants at the vegetative growth stage were submitted to increasing doses of NaCl (0.0, 0.2, 0.4, 0.6, 0.8, and 1.0g per 100g of the substrate). The germination rate was found to be affected a little by the salinity, while the seedlings development was impaired right after germination. Plant in the vegetative growth stage experienced a reduction in the vapotranspiration rates and pigment levels, along with an impairment in the system of capture and use of light, and a decrease in the leaf gas exchange rates, resulting in less accumulation of dry and fresh plant biomass proportional to the salt dose used. Plants started to die within a week at doses ?19.4 dS/m. In conclusion, A10.1 is a glycophyte plant with some level of salt-tolerance and might be used as a model plant to validate salt-tolerance candidate genes/alleles, as well as promoters salt-responsive genes, depending on the right combination of plant age and level of stress. As seed germination is affected only little by salt stress at NaCl doses of about 15 dS/m or less, A10.1 might not be used to validate genes/alleles with a putative role regarding this trait. Setaria viridis (L.) P. Beauv. é uma espécie indicada para ser usada como planta modelo em estudos de genética reversa visando a validação da função de genes. A salinidade do solo é um problema recorrente, presente em mais de 100 países em todo o mundo, e aproximadamente 20% das terras agrícolas do mundo possuem solos salinos e / ou sódicos. O estresse salino afeta todos os principais processos da planta, como germinação, crescimento e, consequentemente, a produtividade. O presente estudo teve como objetivo determinar os níveis de tolerância de S. viridis A10.1 ao estresse salino e identificar seu potencial como planta modelo para validar genes / alelos candidatos à tolerância ao sal, bem como sequências promotoras de genes responsivos ao sal. Em um experimento inicial, as sementes foram semeadas em meio de germinação contendo concentração crescente de NaCl (0, 30, 60, 90, 120 ou 150 mM), e mantidas neste durante a fase inicial de crescimento; e, em outro experimento, as plantas em crescimento vegetativo foram cultivadas com doses crescentes de NaCl (0,0, 0,2, 0,4, 0,6, 0,8 e 1,0g por 100g do substrato). A taxa de germinação foi um pouco afetada pela salinidade, enquanto o desenvolvimento das mudas foi prejudicado logo após a germinação. A planta em fase de crescimento vegetativo experimentou uma redução nas taxas de evapotranspiração e níveis de pigmentos, juntamente com um prejuízo no sistema de captura e uso da luz, e uma diminuição nas taxas de trocas gasosas foliares, resultando em menor acúmulo de biomassa fresca e seca, proporcional à dose de sal utilizada. As plantas começaram a morrer em uma semana com doses ?19,4 dS / m. Em conclusão, A10.1 é uma planta glicófita com algum nível de tolerância ao sal e pode ser usada como planta modelo para validar genes / alelos candidatos à tolerância ao sal, bem como genes promotores responsivos ao sal, dependendo da combinação certa de idade da planta e nível de estresse. Como a germinação da semente é pouco afetada pelo estresse salino em doses de NaCl de cerca de 15 dS / m ou menos, A10.1 não pode ser usado para validar genes / alelos com um papel potencial em relação a essa característica. Made available in DSpace on 2020-12-05T09:02:02Z (GMT). No. of bitstreams: 1 Effect-of-salinity-stress-2020.pdf: 2046420 bytes, checksum: 7370da56cd161d3abc0bbc6a09c4a27e (MD5) Previous issue date: 2020

The American oil palm [Elaeis oleifera (Knuth) Cortés] has pronounced importance in oil palm breeding programs. Here, a germplasm bank (GB) of E. oleifera plants collected in the Amazon rainforest in Brazil was submitted to single nucleotide polymorphism (SNP) marker identification, selection, and use, aiming to characterize genetic diversity and population structure and to design a core collection (CC). Five hundred and fifty-three plants from 206 subsamples, collected at 19 localities spread throughout six geographic regions, were submitted to genotyping-by-sequencing analysis. A set of 1,827 high-quality SNP markers was then selected and used to run the genetic diversity and population structure analysis. The genetic diversity found is of moderate degree, and probably only a small portion of the species diversity is represented in the collection. The possible reason for that is the collecting strategy used, which collected subsamples only around the most prominent watercourses in the region. The average degree of genetic differentiation among subsamples is very high, indicating the presence of high interpopulation differentiation. The collection showed a low level of endogamy. The low average gene flow found indicates that genetic isolation caused by drift is occurring, and there is a need to review the conservation strategy. A set of 245 SNPs distributed throughout all 16 chromosomes was used to design CC based on maximizing the strategy of diversity. The optimal adjustment of the validated parameters, maintained while taking fewest subsamples, led to the choice of a model containing 20% of the entire collection as the ideal to form the CC. Made available in DSpace on 2021-01-13T09:05:49Z (GMT). No. of bitstreams: 1 American-oil-palm-2020.pdf: 2338289 bytes, checksum: bd094acf8939bfe8fed55b69aece920c (MD5) Previous issue date: 2020

The feasibility of thermography as a technique for plant screening aiming at drought-tolerance has been proven by its relationship with gas exchange, biomass, and yield. In this study, unlike most of the previous, thermography was applied for phenotyping contrasting maize genotypes whose classification for drought tolerance had already been established in the field. Our objective was to determine whether thermography-based classification would discriminate the maize genotypes in a similar way as the field selection in which just grain yield was taken into account as a criterion. We evaluated gas exchange, daily water consumption, leaf relative water content, aboveground biomass, and grain yield. Indeed, the screening of maize genotypes based on canopy temperature showed similar results to traditional methods. Nevertheless, canopy temperature only partially reflected gas exchange rates and daily water consumption in plants under drought. Part of the explanation may lie in the changes that drought had caused in plant leaves and canopy structure, altering absorption and dissipation of energy, photosynthesis, transpiration, and partitioning rates. Accordingly, although there was a negative relationship between grain yield and plant canopy temperature, it does not necessarily mean that plants whose canopies were maintained cooler under drought achieved the highest yield. Made available in DSpace on 2019-06-22T00:34:48Z (GMT). No. of bitstreams: 1 SEG05.12.12.001.00.05HUGO3ijms2002273v2.pdf: 6315240 bytes, checksum: ff562dd27405293d1747a55605057985 (MD5) Previous issue date: 2019

American oil palm [Elaeis oleifera (Kunth) Cortes] is known to present a much slower palm oil deterioration rate than African oil palm (E. guineensis Jacq.). In the present study, fatty acid composition, total carotenoids, oil content, and free fatty acid content were characterized for five accessions (Careiro, Anori, Manicoré, Coari, and Autazes) belonging to an American oil palm collection maintained as field gene bank by Embrapa. This germplasm collection was originally collected in different areas in the Brazilian Amazon forest. These accessions were subjected to different storage times (1, 7, and 14 d) before processing to evaluate the quality of the oil produced. Oil content of the dried pulp was found to range between 31.36 and 50.34%. Gas chromatographic analysis revealed that oleic acid is the predominant monounsaturated fatty acid in all five accessions. After 14 d of fruit storage, these accessions were found to maintain low acidity (free fatty acid content), between 1.33 and 2.66%. Total carotenoid content was presented in high concentrations in all five accessions (>1500 mg kg−1). The estimation of genetic parameters showed, in general, high heritability values (>80%), and the estimated genetic gains were generally very high. Coari and Careiro presented the highest oil yields, whereas Manicoré and Coari presented the lowest acidity. These two characteristics are the most important ones when selecting the best parental donor to develop superior interspecific hybrids. Made available in DSpace on 2021-04-19T17:34:13Z (GMT). No. of bitstreams: 1 cs-58-5-19821.pdf: 2157614 bytes, checksum: de927d97b43fc2ae06723da962ec95ac (MD5) Previous issue date: 2018

Many varieties of banana (Musa acuminata) lack resistance to biotic stresses. An EST collection was developed, including transcripts expressed in banana-Mycosphaerella fijiensis interactions. Developed polymorphic gene-derived SSR markers are applicable for genetic mapping, diversity characterization and marker assisted breeding., Background and aims Banana (Musa acuminata) is a crop contributing to global food security. Many varieties lack resistance to biotic stresses, due to sterility and narrow genetic background. The objective of this study was to develop an expressed sequence tag (EST) database of transcripts expressed during compatible and incompatible banana–Mycosphaerella fijiensis (Mf) interactions. Black leaf streak disease (BLSD), caused by Mf, is a destructive disease of banana. Microsatellite markers were developed as a resource for crop improvement. Methodology cDNA libraries were constructed from in vitro-infected leaves from BLSD-resistant M. acuminata ssp. burmaniccoides Calcutta 4 (MAC4) and susceptible M. acuminata cv. Cavendish Grande Naine (MACV). Clones were 5′-end Sanger sequenced, ESTs assembled with TGICL and unigenes annotated using BLAST, Blast2GO and InterProScan. Mreps was used to screen for simple sequence repeats (SSRs), with markers evaluated for polymorphism using 20 diploid (AA) M. acuminata accessions contrasting in resistance to Mycosphaerella leaf spot diseases. Principal results A total of 9333 high-quality ESTs were obtained for MAC4 and 3964 for MACV, which assembled into 3995 unigenes. Of these, 2592 displayed homology to genes encoding proteins with known or putative function, and 266 to genes encoding proteins with unknown function. Gene ontology (GO) classification identified 543 GO terms, 2300 unigenes were assigned to EuKaryotic orthologous group categories and 312 mapped to Kyoto Encyclopedia of Genes and Genomes pathways. A total of 624 SSR loci were identified, with trinucleotide repeat motifs the most abundant in MAC4 (54.1 %) and MACV (57.6 %). Polymorphism across M. acuminata accessions was observed with 75 markers. Alleles per polymorphic locus ranged from 2 to 8, totalling 289. The polymorphism information content ranged from 0.08 to 0.81. Conclusions This EST collection offers a resource for studying functional genes, including transcripts expressed in banana–Mf interactions. Markers are applicable for genetic mapping, diversity characterization and marker-assisted breeding.

Translatable and nontranslatable versions of the coat protein (cp) gene of a Papaya ringspot virus (PRSV) isolate collected in the state of Bahia, Brazil, were engineered for expression in Sunrise and Sunset Solo varieties of papaya (Carica papaya). The biolistic system was used to transform secondary somatic embryo cultures derived from immature zygotic embryos. Fifty-four transgenic lines, 26 translatable and 28 nontranslatable gene versions, were regenerated, with a transformation efficiency of 2.7%. Inoculation of cloned RO plants with PRSV BR, PRSV HA or PRSV TH, Brazilian, Hawaiian and Thai isolates, respectively, revealed !ines with mono-, double-, and triple-resistance. After molecular analysis and a pre!iminary agronomic evaluation, 13 RI and R2 populations were incorporated into the papaya-breeding program at Embrapa Cassava and Tropical Fruits, in Cruz das Almas, Bahia, Brazil. Additional keywords: Carica papaya, potyvirus, resistance, breeding, virus. Desenvolvimento de mamoeiros transgênicos resistentes a vírus expressando o gene da capa protéica de um isolado brasileiro de Papaya ringspot vírus Versões traduzíveis e não traduzíveis do gene da capa protéica (cp) de um isolado de Papaya ringspot virus (PRSV) coletado no Estado da Bahia, Brasil, foram produzidas para expressão nas variedades Sunrise e Sunset Solo de mamoeiro (Carica papaya). O sistema de biobalística foi utilizado para transformar embriões somáticos secundários derivados de embriões zigóticos imaturos. Cinqüenta e quatro linhas transgênicas, sendo 26 contendo versões traduzíveis e 28 contendo versões não traduzíveis do gene cp foram regeneradas, o que resultou em 2,7% de eficiência de transformação, quando considerado o número de linhas transgênicas obtidas por embrião zigótico imaturo excisado. Desafios de plantas RO com PRSV BR, PRSV HA ou PRSV TH, respectivamente isolado brasileiro, havaiano e tailandês, revelaram linhas com resistência a um, dois e três isolados de PRSV. Após análises moleculares e avaliação agronômica preliminar, 13 populações RI e R2 de mamoeiros transgênicos foram incorporadas ao programa de melhoramento genético da Embrapa Mandioca e Fruticultura, em Cruz das Almas, Bahia, Brasil. Palavras-chave adicionais: Carica papaya, potyvirus, resistência, melhoramento, PRSV. Made available in DSpace on 2019-08-09T00:48:26Z (GMT). No. of bitstreams: 1 112122005p.357365.pdf: 8996632 bytes, checksum: 45a64695617448854d15fb8f02360185 (MD5) Previous issue date: 2005