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Papers by Paulo Ricardo Reis Fagundes

Research paper thumbnail of Metodologia para desenvolver linhagens de arroz resistentes a Oryzophagus oryzae por meio de seleção recorrente

Research paper thumbnail of BRS Pelota. Flooded rice cultivar with high grain yield potential

Research paper thumbnail of Progresso genético de linhagens de arroz irrigado para Região Sul do Brasil

O objetivo deste trabalho foi obter essas estimativas para os caracteres producao de graos (kg ha... more O objetivo deste trabalho foi obter essas estimativas para os caracteres producao de graos (kg ha-1), altura de plantas (cm) e dias para o florescimento (dias), do programa de melhoramento de arroz da Embrapa para a regiao Sul do Brasil.

Research paper thumbnail of Desempenho produtivo da cultivar de arroz irrigado BRS Pampa no Rio Grande do Sul safra 2012/2013

Research paper thumbnail of Heterose Em Arroz Híbrido

Current Agricultural Science and Technology, 2014

Vigor hibrido em arroz e resultante de heterose, este vigor hibrido explorado comercialmente e um... more Vigor hibrido em arroz e resultante de heterose, este vigor hibrido explorado comercialmente e uma das mais importantes aplicacoes tecnicas da genetica na agricultura. Este fenomeno contribui nao somente para seguranca alimentar, mas tambem beneficia diretamente o ambiente. O arroz hibrido e cultivado em 15 milhoes de hectares (50% da area total) na China, produzindo 103,5 milhoes de toneladas anualmente (rendimento medio de graos 6.900 kg ha -1 ). A producao comercial de arroz hibrido, dados pertinentes sobre a tecnica, heterose em arroz, base genetica da heterose, interacoes alelicas , interacoes nao alelicas , interacoes entre genes do nucleo e do citoplasma e finalmente, metodologias apropriadas para estimar a heterose com suas respectivas vantagens e desvantagens sao abordadas no presente trabalho.

Research paper thumbnail of Desempenho de linhagens de arroz irrigado no ensaio Regional da Embrapa para o Sul do Brasil

Research paper thumbnail of Proportion of parental line (A receptor and R pollinator) seeds improving rice hybrid production

Acta Scientiarum. Agronomy, 2020

The high price of rice hybrid seeds is one of the major limiting factors for increasing the use o... more The high price of rice hybrid seeds is one of the major limiting factors for increasing the use of this technology. An important step toward minimizing high rice hybrid seed cost is developing techniques that help improve hybrid seed yield. Our goal was to determine the proportion of seeds of line A (receptor) and line R (pollinator) that, under mixed sowing, would allow optimized rice hybrid seed production and grain quality. Trials were performed for two growing seasons in the southern region of Brazil. The cultivar INTA Puita was used as a pollinator and line 464 A as receptor. The experimental design was a randomized block with four replications. Treatments included six proportions of seeds of the INTA Puita (0.75, 1.5, 3.0, 6.0, 12.0, and 24.00%) mixture with seeds of line 464 A (99.25, 98.50, 97.00, 94.00, 88.00, and 76%, respectively). By increasing the percentage of the pollinator seeds (INTA Puita CL) from 0.75 to 24% in the mixture with the receptor (line 464 A), we increa...

Research paper thumbnail of Sensibilidade das Cultivares de Arroz Irrigado 'Carnaroli' e 'Arborio' aos Herbicidas Registrados no Brasil

Research paper thumbnail of Tolerância de genótipos de arroz à salinidade da água de irrigação

Pelotas: Embrapa Clima Temperado, 2015., Dec 28, 2015

Research paper thumbnail of Desempenho da população CNA11 de arroz irrigado no quinto ciclo de seleção recorrente

O objetivo deste trabalho foi avaliar o desempenho da populacao CNA11/5/1 de SR de arroz irrigado... more O objetivo deste trabalho foi avaliar o desempenho da populacao CNA11/5/1 de SR de arroz irrigado, por meio da avaliacao das suas progenies S1.

Research paper thumbnail of Application of stress indexes to evaluate cold tolerance of rice cultivars during the initial stage of plant development

Cold stress has a strong impact on development, reproduction, and plant distribution in Brazil. T... more Cold stress has a strong impact on development, reproduction, and plant distribution in Brazil. The low temperatures usually registered in the state of Rio Grande do Sul is one of the most important factors limiting yields of plants of tropical origin such as is the case of rice. Usually these plants are sensitive to cold stress so that the search for cold tolerant cultivars is of necessity. This is why this study viewed to evaluate whether the cold tolerance indexes, cold susceptibility indexes and the geometric mean are efficient to evaluate cold tolerance of the irrigated rice cultivars ‘Brilhante’, ‘BRS Querencia’, and SCSBRS Tio Taka’ at the plants seedling stage. The speed indexes of the initial stage of development and the indexes of the stages V1, V2, and V3 of each genotype in a stressed environment, in BOD under alternating temperature (13 °C for 10 hours and 18 °C for 14 hours) and in a non stressed environment (greenhouse at 25 °C) were used to calculate the stress index...

Research paper thumbnail of Desenvolvimento de linhagens de arroz resistentes a Oryzophagus oryzae por meio de seleção recorrente

Research paper thumbnail of Desenvolvimento de populações de arroz irrigado pelo método de seleção recorrente

Research paper thumbnail of Embrapa disponibilizará a primeira coleção nuclear temática de arroz para tolerância a temperaturas infraótima

Research paper thumbnail of Uso de graus-dia para estimar a data de diferenciação da panícula (DP) de seis subgrupos de cultivares de arroz irrigado, em 17 localidades do Rio Grande do Sul, visando à adubação nitrogenada em cobertura

Tabelai. NutnerOme'qipdeCjiaS aciJ snJergencia a diferer;Jcia~aoda:paniCDla(ElDPigJd 'mediade~cor... more Tabelai. NutnerOme'qipdeCjiaS aciJ snJergencia a diferer;Jcia~aoda:paniCDla(ElDPigJd 'mediade~correnciada\OP dos ,subgruposda cultivares' de 'arroz' irriga(jpdec,ick>,$fn. .

Research paper thumbnail of Phenylalanine Ammonia-Lyase and Source-Flow-Sink Related Attributes in Rice Genotypes Subjected to High Night Temperatures

Journal of Agricultural Science, 2017

Phenylalanine ammonia-lyase (PAL) which is considered to be one of the main lines of cell acclima... more Phenylalanine ammonia-lyase (PAL) which is considered to be one of the main lines of cell acclimation against stress in plants, non-structural carbohydrates (NSC) accumulation and chlorophyll fluorescence parameters were quantified in two rice genotypes as a function of two temperature regimes: 22/30 °C (control) and 28/30 °C night/day (high night temperatures - HNT), imposed from heading to milk stage. The rice cultivars chosen were Nagina22 (N22) and BRS Querência (BRS-Quer), which are genotypes tolerant and sensitive to high temperatures, respectively. BRS-Quer genotype highlighted more sensitive responses maintaining higher PAL and peroxidase levels on seventh and twenty-first days after stress imposing. On the other hand, this genotype showed levels of fructose, glucose and sucrose decreasingly across stress period whether compared to N22. Both genotypes showed similarity for most of the chlorophyll fluorescence parameters. However, the photosynthesis induction curve highlighte...

Research paper thumbnail of Implicações da seleção recorrente sobre uma população de arroz irrigado

INTRODUÇÃO: A estreita base genética das populações e os métodos tradicionais utilizados no melho... more INTRODUÇÃO: A estreita base genética das populações e os métodos tradicionais utilizados no melhoramento de arroz irrigado (Oryza sativa L.) no Brasil talvez sejam aspectos determinantes para a ausência de novos patamares de rendimento de grãos. Estes métodos maximizam a endogamia e reduzem de maneira drástica as oportunidades de recombinação. Uma das estratégias preconizadas para romper este patamar produtivo estabelecido é a utilização da seleção recorrente. Este método de melhoramento incrementa a freqüência de alelos favoráveis em uma população através de ciclos de seleção e intercruzamentos, explorando a variabilidade genética e resultando em uma maior probabilidade de obtenção de ganhos genéticos. No sul do Brasil, há a disponibilidade da população CNA 11, desenvolvida especificamente para as condições edafoclimáticas da região. Essa população, apesar de ter sofrido avaliações, ainda carece de maiores informações, principalmente, em relação a caracteres envolvidos com a adapta...

Research paper thumbnail of Temperaturas Supraótimas sobre o Arroz Irrigado: Efeitos sobre a Fotossíntese e Esterilidade de Espiguetas

Research paper thumbnail of Accumulated degree-days to reach the main plant developmental stages of irrigated rice cultivars

Agrometeoros

The objective of this study was to determine the accumulated degree-days (DD) to reach six plant ... more The objective of this study was to determine the accumulated degree-days (DD) to reach six plant developmental stages (PDS) of irrigated rice cultivars. Field experiments were carried out at the Estação Experimental Terras Baixas (ETB) of Embrapa Clima Temperado, located in the municipality of Capão do Leão, State of Rio Grande do Sul, Brazil, during 12 crop seasons, using six sowing dates in each. Ten plants of each cultivar were tagged and had each of the PDS monitored throughout the crop cycle. The DD (°C day) were calculated as the sum of the daily values resulting from the difference between mean air temperature (Tm) and the minimal base temperature (Tb = 11 °C), from the emergence until the date of each PDS. The results indicated that the DD to reach anthesis (R4) represented, in the average, about 77% of the total cycle (R9), ranging from 73% for IRGA 421 to 91% for Epagri 109. The vegetative period (from E-emergence to R1) is the one with the highest average DD value, around 48% of the total cycle, presenting also the largest differences between cultivars when compared to the reproductive period 1 (R1-R4) and the reproductive period 2 (R4-R9).

Research paper thumbnail of Number of days to reach the main plant developmental stages of irrigated rice cultivars

Agrometeoros

The objective of this study was to determine the number of days (ND) to reach the main plant deve... more The objective of this study was to determine the number of days (ND) to reach the main plant developmental stages (PDS) of irrigated rice cultivars. Field experiments were carried out at the Estação Experimental Terras Baixas (ETB) of Embrapa Clima Temperado, located in the municipality of Capão do Leão, State of Rio Grande do Sul, Brazil, during 12 crop seasons, using six sowing dates in each. Ten plants from each cultivar were tagged and had each of the PDS monitored throughout the crop cycle. The results indicated that the ND to reach each of the six PDS varied according to the cycle of the cultivars and that there was statistical difference between some of them. The ND to reach the stages R1 (panicle differentiation), R4 (anthesis) and R9 (complete panicle maturity) of the cultivar IRGA 424, for example, were 63, 96 and 125, respectively. The average number of days to reach the different plant developmental stages varies according to the cycle length of the cultivars, and the subperiod of longer duration is that between the four-leaf and panicle differentiation stages (V4-R1).

Research paper thumbnail of Metodologia para desenvolver linhagens de arroz resistentes a Oryzophagus oryzae por meio de seleção recorrente

Research paper thumbnail of BRS Pelota. Flooded rice cultivar with high grain yield potential

Research paper thumbnail of Progresso genético de linhagens de arroz irrigado para Região Sul do Brasil

O objetivo deste trabalho foi obter essas estimativas para os caracteres producao de graos (kg ha... more O objetivo deste trabalho foi obter essas estimativas para os caracteres producao de graos (kg ha-1), altura de plantas (cm) e dias para o florescimento (dias), do programa de melhoramento de arroz da Embrapa para a regiao Sul do Brasil.

Research paper thumbnail of Desempenho produtivo da cultivar de arroz irrigado BRS Pampa no Rio Grande do Sul safra 2012/2013

Research paper thumbnail of Heterose Em Arroz Híbrido

Current Agricultural Science and Technology, 2014

Vigor hibrido em arroz e resultante de heterose, este vigor hibrido explorado comercialmente e um... more Vigor hibrido em arroz e resultante de heterose, este vigor hibrido explorado comercialmente e uma das mais importantes aplicacoes tecnicas da genetica na agricultura. Este fenomeno contribui nao somente para seguranca alimentar, mas tambem beneficia diretamente o ambiente. O arroz hibrido e cultivado em 15 milhoes de hectares (50% da area total) na China, produzindo 103,5 milhoes de toneladas anualmente (rendimento medio de graos 6.900 kg ha -1 ). A producao comercial de arroz hibrido, dados pertinentes sobre a tecnica, heterose em arroz, base genetica da heterose, interacoes alelicas , interacoes nao alelicas , interacoes entre genes do nucleo e do citoplasma e finalmente, metodologias apropriadas para estimar a heterose com suas respectivas vantagens e desvantagens sao abordadas no presente trabalho.

Research paper thumbnail of Desempenho de linhagens de arroz irrigado no ensaio Regional da Embrapa para o Sul do Brasil

Research paper thumbnail of Proportion of parental line (A receptor and R pollinator) seeds improving rice hybrid production

Acta Scientiarum. Agronomy, 2020

The high price of rice hybrid seeds is one of the major limiting factors for increasing the use o... more The high price of rice hybrid seeds is one of the major limiting factors for increasing the use of this technology. An important step toward minimizing high rice hybrid seed cost is developing techniques that help improve hybrid seed yield. Our goal was to determine the proportion of seeds of line A (receptor) and line R (pollinator) that, under mixed sowing, would allow optimized rice hybrid seed production and grain quality. Trials were performed for two growing seasons in the southern region of Brazil. The cultivar INTA Puita was used as a pollinator and line 464 A as receptor. The experimental design was a randomized block with four replications. Treatments included six proportions of seeds of the INTA Puita (0.75, 1.5, 3.0, 6.0, 12.0, and 24.00%) mixture with seeds of line 464 A (99.25, 98.50, 97.00, 94.00, 88.00, and 76%, respectively). By increasing the percentage of the pollinator seeds (INTA Puita CL) from 0.75 to 24% in the mixture with the receptor (line 464 A), we increa...

Research paper thumbnail of Sensibilidade das Cultivares de Arroz Irrigado 'Carnaroli' e 'Arborio' aos Herbicidas Registrados no Brasil

Research paper thumbnail of Tolerância de genótipos de arroz à salinidade da água de irrigação

Pelotas: Embrapa Clima Temperado, 2015., Dec 28, 2015

Research paper thumbnail of Desempenho da população CNA11 de arroz irrigado no quinto ciclo de seleção recorrente

O objetivo deste trabalho foi avaliar o desempenho da populacao CNA11/5/1 de SR de arroz irrigado... more O objetivo deste trabalho foi avaliar o desempenho da populacao CNA11/5/1 de SR de arroz irrigado, por meio da avaliacao das suas progenies S1.

Research paper thumbnail of Application of stress indexes to evaluate cold tolerance of rice cultivars during the initial stage of plant development

Cold stress has a strong impact on development, reproduction, and plant distribution in Brazil. T... more Cold stress has a strong impact on development, reproduction, and plant distribution in Brazil. The low temperatures usually registered in the state of Rio Grande do Sul is one of the most important factors limiting yields of plants of tropical origin such as is the case of rice. Usually these plants are sensitive to cold stress so that the search for cold tolerant cultivars is of necessity. This is why this study viewed to evaluate whether the cold tolerance indexes, cold susceptibility indexes and the geometric mean are efficient to evaluate cold tolerance of the irrigated rice cultivars ‘Brilhante’, ‘BRS Querencia’, and SCSBRS Tio Taka’ at the plants seedling stage. The speed indexes of the initial stage of development and the indexes of the stages V1, V2, and V3 of each genotype in a stressed environment, in BOD under alternating temperature (13 °C for 10 hours and 18 °C for 14 hours) and in a non stressed environment (greenhouse at 25 °C) were used to calculate the stress index...

Research paper thumbnail of Desenvolvimento de linhagens de arroz resistentes a Oryzophagus oryzae por meio de seleção recorrente

Research paper thumbnail of Desenvolvimento de populações de arroz irrigado pelo método de seleção recorrente

Research paper thumbnail of Embrapa disponibilizará a primeira coleção nuclear temática de arroz para tolerância a temperaturas infraótima

Research paper thumbnail of Uso de graus-dia para estimar a data de diferenciação da panícula (DP) de seis subgrupos de cultivares de arroz irrigado, em 17 localidades do Rio Grande do Sul, visando à adubação nitrogenada em cobertura

Tabelai. NutnerOme'qipdeCjiaS aciJ snJergencia a diferer;Jcia~aoda:paniCDla(ElDPigJd 'mediade~cor... more Tabelai. NutnerOme'qipdeCjiaS aciJ snJergencia a diferer;Jcia~aoda:paniCDla(ElDPigJd 'mediade~correnciada\OP dos ,subgruposda cultivares' de 'arroz' irriga(jpdec,ick>,$fn. .

Research paper thumbnail of Phenylalanine Ammonia-Lyase and Source-Flow-Sink Related Attributes in Rice Genotypes Subjected to High Night Temperatures

Journal of Agricultural Science, 2017

Phenylalanine ammonia-lyase (PAL) which is considered to be one of the main lines of cell acclima... more Phenylalanine ammonia-lyase (PAL) which is considered to be one of the main lines of cell acclimation against stress in plants, non-structural carbohydrates (NSC) accumulation and chlorophyll fluorescence parameters were quantified in two rice genotypes as a function of two temperature regimes: 22/30 °C (control) and 28/30 °C night/day (high night temperatures - HNT), imposed from heading to milk stage. The rice cultivars chosen were Nagina22 (N22) and BRS Querência (BRS-Quer), which are genotypes tolerant and sensitive to high temperatures, respectively. BRS-Quer genotype highlighted more sensitive responses maintaining higher PAL and peroxidase levels on seventh and twenty-first days after stress imposing. On the other hand, this genotype showed levels of fructose, glucose and sucrose decreasingly across stress period whether compared to N22. Both genotypes showed similarity for most of the chlorophyll fluorescence parameters. However, the photosynthesis induction curve highlighte...

Research paper thumbnail of Implicações da seleção recorrente sobre uma população de arroz irrigado

INTRODUÇÃO: A estreita base genética das populações e os métodos tradicionais utilizados no melho... more INTRODUÇÃO: A estreita base genética das populações e os métodos tradicionais utilizados no melhoramento de arroz irrigado (Oryza sativa L.) no Brasil talvez sejam aspectos determinantes para a ausência de novos patamares de rendimento de grãos. Estes métodos maximizam a endogamia e reduzem de maneira drástica as oportunidades de recombinação. Uma das estratégias preconizadas para romper este patamar produtivo estabelecido é a utilização da seleção recorrente. Este método de melhoramento incrementa a freqüência de alelos favoráveis em uma população através de ciclos de seleção e intercruzamentos, explorando a variabilidade genética e resultando em uma maior probabilidade de obtenção de ganhos genéticos. No sul do Brasil, há a disponibilidade da população CNA 11, desenvolvida especificamente para as condições edafoclimáticas da região. Essa população, apesar de ter sofrido avaliações, ainda carece de maiores informações, principalmente, em relação a caracteres envolvidos com a adapta...

Research paper thumbnail of Temperaturas Supraótimas sobre o Arroz Irrigado: Efeitos sobre a Fotossíntese e Esterilidade de Espiguetas

Research paper thumbnail of Accumulated degree-days to reach the main plant developmental stages of irrigated rice cultivars

Agrometeoros

The objective of this study was to determine the accumulated degree-days (DD) to reach six plant ... more The objective of this study was to determine the accumulated degree-days (DD) to reach six plant developmental stages (PDS) of irrigated rice cultivars. Field experiments were carried out at the Estação Experimental Terras Baixas (ETB) of Embrapa Clima Temperado, located in the municipality of Capão do Leão, State of Rio Grande do Sul, Brazil, during 12 crop seasons, using six sowing dates in each. Ten plants of each cultivar were tagged and had each of the PDS monitored throughout the crop cycle. The DD (°C day) were calculated as the sum of the daily values resulting from the difference between mean air temperature (Tm) and the minimal base temperature (Tb = 11 °C), from the emergence until the date of each PDS. The results indicated that the DD to reach anthesis (R4) represented, in the average, about 77% of the total cycle (R9), ranging from 73% for IRGA 421 to 91% for Epagri 109. The vegetative period (from E-emergence to R1) is the one with the highest average DD value, around 48% of the total cycle, presenting also the largest differences between cultivars when compared to the reproductive period 1 (R1-R4) and the reproductive period 2 (R4-R9).

Research paper thumbnail of Number of days to reach the main plant developmental stages of irrigated rice cultivars

Agrometeoros

The objective of this study was to determine the number of days (ND) to reach the main plant deve... more The objective of this study was to determine the number of days (ND) to reach the main plant developmental stages (PDS) of irrigated rice cultivars. Field experiments were carried out at the Estação Experimental Terras Baixas (ETB) of Embrapa Clima Temperado, located in the municipality of Capão do Leão, State of Rio Grande do Sul, Brazil, during 12 crop seasons, using six sowing dates in each. Ten plants from each cultivar were tagged and had each of the PDS monitored throughout the crop cycle. The results indicated that the ND to reach each of the six PDS varied according to the cycle of the cultivars and that there was statistical difference between some of them. The ND to reach the stages R1 (panicle differentiation), R4 (anthesis) and R9 (complete panicle maturity) of the cultivar IRGA 424, for example, were 63, 96 and 125, respectively. The average number of days to reach the different plant developmental stages varies according to the cycle length of the cultivars, and the subperiod of longer duration is that between the four-leaf and panicle differentiation stages (V4-R1).