Genotypic values and genetic correlations for components and oil content of bunch of hybrids between caiaué and dendê / Valores genotípicos e correlações genéticas para componentes e teor de óleo do cacho de híbridos entre caiaué e dendê

Interspecific hybridization between Elaeis oleifera and Elaeis guineensis (HIE OxG) is explored in plant breeding programs to meet the demand for resistant cultivars to fatal yellowing, which is the biggest phytosanitary problem in E. guineensis plants in South America, including Brazil. In addition to resistance to fatal yellowing, cultivars should have high oil yield, which depends directly on bunch production and oil content in the bunches (O/FFB). The obtaining of genetic gains in O/FFBfor OxG requires information on the genotypic values of the breeding population and the understanding of how the components of the bunch are related to this characteristic in this type of material. Thus, the objective of this work was to estimate genotypic values and genetic correlations for bunch components and analyze the potential of using these components in the selection of gains for O/FFB. The physical composition and oil content in mesocarp of 840 bunches from 39 HIE OxG F1 progenies were analyzed. Genotypic values for bunch components were estimated using the procedure REML/BLUP and were obtained from genetic correlations between them. All evaluated components presented genetic variation with possibility of gains through selection, especially the oil content in the bunch (O/FFB), which presented variability above 23%. The selection for O/FFBwill mainly result in bunches with a higher fruit proportion over the weight of the bunch (TF/FFB), greater oil contents in mesocarp of normal and parthenocarpic fruits, and lower proportion of empty spikelets. Considering the high and positive correlations between O/FFBand the evaluated characteristics and the practicality of evaluation, the characteristics with higher potential for indirect selection to increase O/FFBare TF/FFBand proportion of mesocarp in normal fruits.(AU)

A hibridação interespecífica entre caiaué e dendê (HIE OxG) é explorada no melhoramento genético para atender a demanda de cultivares resistentes ao amarelecimento fatal (AF), maior problema fitossanitário do dendê na América do Sul, incluindo o Brasil. Além da resistência ao AF, as cultivares devem apresentar alta produtividade em óleo, que depende diretamente da produção de cachos e do teor de óleo nos cachos (O/CFF). Para obter ganhos genéticos em O/CFF de HIE OxG é necessário conhecer os valores genotípicos da população de melhoramento e como os componentes docacho estão relacionados a esta característica neste tipo de material. O objetivo deste estudo foi estimar valores genotípicos e correlações genéticas para componentes de cacho e analisar o potencial de uso desses componentes na seleção para ganho em O/CFF. Análises de composição física e do teor de óleo no mesocarpo foram realizadas em 840 cachos de 39 progênies HIE OxG F1. Valores genotípicos para os componentes de cacho foram estimados por procedimento REML/BLUPe obtidas às correlações genéticas entre eles. Todos os componentes avaliados apresentaram variação genética com possibilidade de ganhos por seleção, com destaque para valores do teor de óleo no cacho (O/CFF) superiores a 23%. A seleção para O/CFF resultará, principalmente, em cachos com maior proporção de frutos sobre o peso do cacho (F/CFF) e maiores teores de óleo no mesocarpo de frutos normais e partenocárpicos, bem como, com menor proporção de espiguetas vazias. Devido as correlações altas e positivas com O/CFF e pela praticidade de avaliação, as características com maior potencial para seleção indireta para aumento de O/CFF são F/CFF e proporção de mesocarpo nos frutos normais.(AU)

Genotypic values and genetic correlations for components and oil content of bunch of hybrids between caiaué and dendê / Valores genotípicos e correlações genéticas para componentes e teor de óleo do cacho de híbridos entre caiaué e dendê

Interspecific hybridization between Elaeis oleifera and Elaeis guineensis (HIE OxG) is explored in plant breeding programs to meet the demand for resistant cultivars to fatal yellowing, which is the biggest phytosanitary problem in E. guineensis plants in South America, including Brazil. In addition to resistance to fatal yellowing, cultivars should have high oil yield, which depends directly on bunch production and oil content in the bunches (O/FFB). The obtaining of genetic gains in O/FFBfor OxG requires information on the genotypic values of the breeding population and the understanding of how the components of the bunch are related to this characteristic in this type of material. Thus, the objective of this work was to estimate genotypic values and genetic correlations for bunch components and analyze the potential of using these components in the selection of gains for O/FFB. The physical composition and oil content in mesocarp of 840 bunches from 39 HIE OxG F1 progenies were analyzed. Genotypic values for bunch components were estimated using the procedure REML/BLUP and were obtained from genetic correlations between them. All evaluated components presented genetic variation with possibility of gains through selection, especially the oil content in the bunch (O/FFB), which presented variability above 23%. The selection for O/FFBwill mainly result in bunches with a higher fruit proportion over the weight of the bunch (TF/FFB), greater oil contents in mesocarp of normal and parthenocarpic fruits, and lower proportion of empty spikelets. Considering the high and positive correlations between O/FFBand the evaluated characteristics and the practicality of evaluation, the characteristics with higher potential for indirect selection to increase O/FFBare TF/FFBand proportion of mesocarp in normal fruits.

A hibridação interespecífica entre caiaué e dendê (HIE OxG) é explorada no melhoramento genético para atender a demanda de cultivares resistentes ao amarelecimento fatal (AF), maior problema fitossanitário do dendê na América do Sul, incluindo o Brasil. Além da resistência ao AF, as cultivares devem apresentar alta produtividade em óleo, que depende diretamente da produção de cachos e do teor de óleo nos cachos (O/CFF). Para obter ganhos genéticos em O/CFF de HIE OxG é necessário conhecer os valores genotípicos da população de melhoramento e como os componentes docacho estão relacionados a esta característica neste tipo de material. O objetivo deste estudo foi estimar valores genotípicos e correlações genéticas para componentes de cacho e analisar o potencial de uso desses componentes na seleção para ganho em O/CFF. Análises de composição física e do teor de óleo no mesocarpo foram realizadas em 840 cachos de 39 progênies HIE OxG F1. Valores genotípicos para os componentes de cacho foram estimados por procedimento REML/BLUPe obtidas às correlações genéticas entre eles. Todos os componentes avaliados apresentaram variação genética com possibilidade de ganhos por seleção, com destaque para valores do teor de óleo no cacho (O/CFF) superiores a 23%. A seleção para O/CFF resultará, principalmente, em cachos com maior proporção de frutos sobre o peso do cacho (F/CFF) e maiores teores de óleo no mesocarpo de frutos normais e partenocárpicos, bem como, com menor proporção de espiguetas vazias. Devido as correlações altas e positivas com O/CFF e pela praticidade de avaliação, as características com maior potencial para seleção indireta para aumento de O/CFF são F/CFF e proporção de mesocarpo nos frutos normais.

Effect of month of conception on fertility of mares inseminated with jackass semen / Influência do mês da concepção sobre a eficiência reprodutiva de éguas inseminadas com sêmen asinino

Fertility obtained by cross-breeding mares (Equus caballus) with jackasses (Equus asinus) was evaluated. Two extenders, containing skim milk-glucose or egg yolk-glycine were used to study the fertility of mares inseminated with diluted jackass semen (T1 and T2) or diluted and cooled semen at 5°C for 12 hours (T3 and T4). A total of 272 cycles of 208 mares of undefined breeds were evaluated, being uniformly distributed between groups. The cycles were controlled by transrectal palpation and teasing, and mares were inseminated every Tuesday, Thursday and Saturday (three times/week), from the detection of a follicle with 3.0 to 3.5cm diameter in one of the ovaries until ovulation. Pregnancy was detected using transrectal palpation, teasing and ultrasound exams every 14 days. The extenders had no effect on fertility (P>0.05). Pregnancy rates for the first cycle were 64.52%, 61.11%, 50.72% and 54.17% and pregnancy rates/cycle were 63.64%, 54.55%, 52.69% and 47.06%, respectively, for T1, T2, T3 and T4. Differences in pregnancy loss rates between groups and effect of month of conception on fertility were found. Pregnancy loss rates were significantly higher (P<0.05) in January (38.46%) and in February and March (52.38%), with an average of 33.09%. The results indicate that mares conceiving at the end of the physiological reproduction time, carrying a mule embryo, are more susceptible to pregnancy loss.(AU)

Avaliou-se a eficiência reprodutiva de cruzamentos interespécies entre fêmeas equinas e reprodutores asininos da raça Pêga. Para tal, estudou-se o efeito de dois diluidores, à base de leite em pó desnatado-glicose ou glicina-gema de ovo, sobre a fertilidade de éguas inseminadas com sêmen fresco diluído (T1 e T2) ou diluído e resfriado a 5°C por 12 horas (T3 e T4). Foram utilizados 272 ciclos de 208 éguas mestiças, distribuídas uniformemente entre os tratamentos, após agrupamento por idade e categoria reprodutiva. Os ciclos foram acompanhados por palpação retal e rufiação, sendo as inseminações realizadas às terças, quintas e aos sábados (três vezes por semana), a partir da detecção de um folículo de 3,0 a 3,5cm de diâmetro, em um dos ovários, até a ovulação. As gestações foram acompanhadas por palpação transretal, rufiação e por ultrassonografia, realizada a cada 14 dias. As taxas de gestação obtidas, ao primeiro ciclo, não diferiram (P>0,05) entre os tratamentos, sendo de 64,52% para T1, 61,11% para T2, 50,72% para T3 e 54,17% para T4. Da mesma maneira, as taxas de gestação por ciclo também não foram influenciadas (P>0,05) pelos tratamentos, com valores de 63,64%, 54,55%, 52,69% e 47,06% para T1, T2, T3, e T4, respectivamente. No que diz respeito às taxas de perdas gestacionais, obtidas por meio das taxas de perdas e de perdas ajustadas, houve influência (P<0,05) dos tratamentos. Observou-se, ainda, efeito do mês da concepção, com taxas de perda superiores para os meses de janeiro (38,46%) e de fevereiro e março (52,38%), sendo a média de 33,09%. Sugere-se que a redução dos padrões de secreção do LH, ao final da estação de monta, responda pelas maiores taxas de perdas gestacionais do cruzamento interespécie, notadamente naquelas éguas que conceberam no final da estação de monta fisiológica dos equinos.(AU)

Forage performance of Paspalum hybrids from an interspecific cross / Desempenho forrageiro de híbridos de Paspalum obtidos por meio de cruzamentos interespecíficos

The goal of this study was to assess the variability of Paspalum plicatulum x P. guenoarum interspecific hybrids in terms of agronomic performance and their tolerance to cold conditions, as well as to estimate the correlation of different phenotypic characters associated with forage production. Twenty hybrids plants were used, besides one access P. guenoarum , one of P. plicatulum and the cultivar 'Pensacola' ( P. notatum ). Assessments were performed on individual plants, in a completely randomized design with five repetitions. Paspalum genotypes presented variability in total dry matter, leaf dry mass, leaf: stem ratio, and tolerance to cold. We suggest selection of the hybrids 08Q01 and 08Q44 for new stages within a forage improvement program. Estimates of phenotypic correlation may aid in the selection of genotypes with better agronomic traits.(AU)

O objetivo deste estudo foi avaliar a variabilidade de híbridos interespecíficos de Paspalum plicatulum x P. guenoarum por meio do desempenho agronômico e tolerância ao frio, bem como estimar as correlações fenotípicas de diferentes caracteres ligados à produção de forragem. Foram utilizados 20 híbridos, um acesso de P. guenoarum , um de P. plicatulum e a cultivar 'Pensacola' ( P. notatum ). As avaliações foram realizadas em plantas individuais, em delineamento completamente casualizado, com cinco repetições. Os genótipos de Paspalum apresentam variabilidade para massa seca total, massa seca de folhas e relação folha: colmo e na tolerância ao frio. É possível selecionar os híbridos 08Q01 e 08Q44 para novas etapas dentro de um programa de melhoramento de forrageiras. As estimativas de correlações fenotípicas podem auxiliar na seleção de genótipos com caracteres agronômicos superiores.(AU)

Interspecific hybrids between Paspalum plicatulum and P. oteroi: a key tool for forage breeding

Grama-tio-pedro (Paspalum oteroi Swallen) is a rare stoloniferous grass of the Plicatula group of Paspalum, well adapted to continuous grazing in areas subject to seasonal flooding in the Pantanal region, in central western Brazil. The species is a facultative apomictic (asexual reproduction by seed) tetraploid, sporadically cultivated on Pantanal farms, propagated either by cuttings or seed. Due to its potential for extensive cultivation and forage quality, Grama-tio-pedro appears as a candidate for genetic improvement within the Plicatula group through plant breeding. We used a colchicine-induced sexual autotetraploid genotype of P. plicatulum Michx. to obtain interspecific hybrids using the apomictic species, P. oteroi, as pollen donor. The very similar meiotic chromosome behavior observed in both parents, with main quadrivalent and bivalent associations, suggested that P. oteroi is a natural autotetraploid. The hybrids showed less irregular meiotic behavior with fewer quadrivalents and more bivalents than either parent. Fertility among interspecific hybrids varied from complete sterility in some of them to seed productions in others that were approximately twice as much as for either parent. The great variability of seed set performance may well be a drastic genetic consequence of joining two homologous chromosome sets of P. plicatulum together with two homologous sets of P. oteroi that, in turn, have some homeology between them. Most hybrids reproduce by sexual means, thus, they could be used as female parents in backcrosses and in crosses with other species of the Plicatula group for interspecific gene transferring in breeding programs.

Interspecific hybrids between Paspalum plicatulum and P. oteroi: a key tool for forage breeding

Grama-tio-pedro (Paspalum oteroi Swallen) is a rare stoloniferous grass of the Plicatula group of Paspalum, well adapted to continuous grazing in areas subject to seasonal flooding in the Pantanal region, in central western Brazil. The species is a facultative apomictic (asexual reproduction by seed) tetraploid, sporadically cultivated on Pantanal farms, propagated either by cuttings or seed. Due to its potential for extensive cultivation and forage quality, Grama-tio-pedro appears as a candidate for genetic improvement within the Plicatula group through plant breeding. We used a colchicine-induced sexual autotetraploid genotype of P. plicatulum Michx. to obtain interspecific hybrids using the apomictic species, P. oteroi, as pollen donor. The very similar meiotic chromosome behavior observed in both parents, with main quadrivalent and bivalent associations, suggested that P. oteroi is a natural autotetraploid. The hybrids showed less irregular meiotic behavior with fewer quadrivalents and more bivalents than either parent. Fertility among interspecific hybrids varied from complete sterility in some of them to seed productions in others that were approximately twice as much as for either parent. The great variability of seed set performance may well be a drastic genetic consequence of joining two homologous chromosome sets of P. plicatulum together with two homologous sets of P. oteroi that, in turn, have some homeology between them. Most hybrids reproduce by sexual means, thus, they could be used as female parents in backcrosses and in crosses with other species of the Plicatula group for interspecific gene transferring in breeding programs.(AU)

Hybrids between Pseudoplatystoma corruscans and P. reticulatum (Siluriformes: Pimelodidae) previously reported in the Upper Paraná River are likely escapes from aquaculture farms: evidence from microsatellite markers

The production of hybrids of the 'pintado', Pseudoplatystoma corruscans (Spix & Agassiz, 1829) and 'cachara', Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889) in captivity has generated many concerns about the possibility of introduction of farmed hybrids into natural environments. In the last decade, hybrids between these species, known as 'pintachara' or 'cachapinta', were reported from different regions of the Upper Paraná River basin. Prospection of these hybrids is important in order to orient conservation programs for the species involved. Knowledge of the presence of these hybrids will direct conservation strategies towards prevention and/or mitigation of the effects of cross breeding in natural populations of P. corruscans (the native species of the genus) and farmed hybrids. In this study, surveyed the larval population using molecular tools to detect the presence and assess the origin (natural hybridization or escapes from fish farms) of hybrids in natural water bodies. Nine microsatellite markers were used to detect signals of hybridization and introgression of P. reticulatum in larvae and adults of P. corruscans in Upper Paraná River basin, between Itaipu Dam and Porto Primavera Dam. The specimens were sampled in the Upper Paraná channel and in tributaries where hybrids had been detected in the past, during two reproductive seasons. Despite of that, no sign of hybridization and introgression was found in the 171 larvae and 75 adults sampled, suggesting that the specimens detected in previous studies had originated from escapes of aquaculture farms.

Hybrids between Pseudoplatystoma corruscans and P. reticulatum (Siluriformes: Pimelodidae) previously reported in the Upper Paraná River are likely escapes from aquaculture farms: evidence from microsatellite markers

The production of hybrids of the 'pintado', Pseudoplatystoma corruscans (Spix & Agassiz, 1829) and 'cachara', Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889) in captivity has generated many concerns about the possibility of introduction of farmed hybrids into natural environments. In the last decade, hybrids between these species, known as 'pintachara' or 'cachapinta', were reported from different regions of the Upper Paraná River basin. Prospection of these hybrids is important in order to orient conservation programs for the species involved. Knowledge of the presence of these hybrids will direct conservation strategies towards prevention and/or mitigation of the effects of cross breeding in natural populations of P. corruscans (the native species of the genus) and farmed hybrids. In this study, surveyed the larval population using molecular tools to detect the presence and assess the origin (natural hybridization or escapes from fish farms) of hybrids in natural water bodies. Nine microsatellite markers were used to detect signals of hybridization and introgression of P. reticulatum in larvae and adults of P. corruscans in Upper Paraná River basin, between Itaipu Dam and Porto Primavera Dam. The specimens were sampled in the Upper Paraná channel and in tributaries where hybrids had been detected in the past, during two reproductive seasons. Despite of that, no sign of hybridization and introgression was found in the 171 larvae and 75 adults sampled, suggesting that the specimens detected in previous studies had originated from escapes of aquaculture farms.(AU)

Morphological characterization and reproductive aspects in genetic variability studies of forage peanut

Morphological characterization and the study of reproductive behavior are important procedures to identify desirable traits of progenitors to be included in breeding programs. Morphological descriptors and the reproductive behavior of parental accessions of the legumes Arachis pintoi Krapov & W.C.Gregory and A. repens Handro were analyzed looking for the probable causes of seed production variability. Morphological and reproductive characterization were used for the estimation of the genetic variability of five A. pintoi and two A. repens accessions, with crosses being conducted in a greenhouse. Parents and hybrids have shown high pollen stainability, regular meiosis (2n=20), and presented distinctive reproductive behaviors: A. pintoi accessions GK 12787, V 13468 and V 6791-wf are prolific seed producers, while A. pintoi V 13167, V 13338 and A. repens Nc 1579 and Nc 1578, rarely produce seeds. Intraspecific crosses generated fertile F1 and F2 hybrids from five combinations. Interspecific crosses produced sterile F1 hybrids. Stigma morphology and distinct mode of reproduction present among accessions suggest possible barriers for seed production in some cross-combinations. Euclidian distance range between parents was 0.20 to 5.52. Accessions GK 12787 and Nc 1579 presented the maximum distance: 5.52, and V 13468 and Nc 1579 the minimum distance: 0.20. The Euclidian distance was considered an adequate methodology to study genetic diversity of parental accessions.

A caracterização morfológica e o estudo do comportamento reprodutivo são procedimentos importantes para definir caracteres desejáveis nos progenitores a serem incluídos em programas de melhoramento. Descritores morfológicos foram aplicados e foi avaliado o comportamento reprodutivo na busca das prováveis causas da produção variável de sementes entre acessos parentais das leguminosas Arachis pintoi Krapov & W.C.Gregory e A. repens Handro. A caracterização morfológica e reprodutiva foi utilizada para avaliação da variabilidade genética em cinco acessos de A. pintoi e dois acessos de A. repens e os cruzamentos foram realizados em casa de vegetação. Os parentais apresentaram alta corabilidade do pólen, meiose regular (2n=20), e variação no comportamento reprodutivo: A. pintoi GK 12787, V 13468 e V 6791-wf são prolíficos, enquanto A. pintoi V 13167, V 13338 e A. repens Nc 1579 e Nc 1578 raramente produzem sementes. Os cruzamentos intra-específicos geraram híbridos F1 e F2 férteis em cinco combinações. Os cruzamentos interespecíficos produziram híbridos F1 estéreis. A morfologia do estigma e o modo de reprodução presente nos acessos sugerem possíveis barreiras para a produção de sementes em alguns cruzamentos. A Distância Euclidiana entre os parentais variou de 0,20 a 5,52. Os acessos GK 12787 e Nc 1579 apresentaram a maior distância (5,52) e V 13468 e Nc 1579 apresentaram a menor distância (0,20). A Distância Euclidiana foi considerada uma metodologia adequada para estudos de diversidade genética em acessos parentais.

Morphological characterization and reproductive aspects in genetic variability studies of forage peanut

Morphological characterization and the study of reproductive behavior are important procedures to identify desirable traits of progenitors to be included in breeding programs. Morphological descriptors and the reproductive behavior of parental accessions of the legumes Arachis pintoi Krapov & W.C.Gregory and A. repens Handro were analyzed looking for the probable causes of seed production variability. Morphological and reproductive characterization were used for the estimation of the genetic variability of five A. pintoi and two A. repens accessions, with crosses being conducted in a greenhouse. Parents and hybrids have shown high pollen stainability, regular meiosis (2n=20), and presented distinctive reproductive behaviors: A. pintoi accessions GK 12787, V 13468 and V 6791-wf are prolific seed producers, while A. pintoi V 13167, V 13338 and A. repens Nc 1579 and Nc 1578, rarely produce seeds. Intraspecific crosses generated fertile F1 and F2 hybrids from five combinations. Interspecific crosses produced sterile F1 hybrids. Stigma morphology and distinct mode of reproduction present among accessions suggest possible barriers for seed production in some cross-combinations. Euclidian distance range between parents was 0.20 to 5.52. Accessions GK 12787 and Nc 1579 presented the maximum distance: 5.52, and V 13468 and Nc 1579 the minimum distance: 0.20. The Euclidian distance was considered an adequate methodology to study genetic diversity of parental accessions.

A caracterização morfológica e o estudo do comportamento reprodutivo são procedimentos importantes para definir caracteres desejáveis nos progenitores a serem incluídos em programas de melhoramento. Descritores morfológicos foram aplicados e foi avaliado o comportamento reprodutivo na busca das prováveis causas da produção variável de sementes entre acessos parentais das leguminosas Arachis pintoi Krapov & W.C.Gregory e A. repens Handro. A caracterização morfológica e reprodutiva foi utilizada para avaliação da variabilidade genética em cinco acessos de A. pintoi e dois acessos de A. repens e os cruzamentos foram realizados em casa de vegetação. Os parentais apresentaram alta corabilidade do pólen, meiose regular (2n=20), e variação no comportamento reprodutivo: A. pintoi GK 12787, V 13468 e V 6791-wf são prolíficos, enquanto A. pintoi V 13167, V 13338 e A. repens Nc 1579 e Nc 1578 raramente produzem sementes. Os cruzamentos intra-específicos geraram híbridos F1 e F2 férteis em cinco combinações. Os cruzamentos interespecíficos produziram híbridos F1 estéreis. A morfologia do estigma e o modo de reprodução presente nos acessos sugerem possíveis barreiras para a produção de sementes em alguns cruzamentos. A Distância Euclidiana entre os parentais variou de 0,20 a 5,52. Os acessos GK 12787 e Nc 1579 apresentaram a maior distância (5,52) e V 13468 e Nc 1579 apresentaram a menor distância (0,20). A Distância Euclidiana foi considerada uma metodologia adequada para estudos de diversidade genética em acessos parentais.