Combining disease resistance and postharvest quality traits by early marker-assisted backcrossing in carioca beans

ABSTRACT: Common bean is a worldwide important crop. The development of varieties with durable resistance to diseases is a major challenge in common bean breeding. The present study aimed at evaluating the phenotypic and molecular selection of anthracnose resistance in a population obtained by assisted backcrossing from IAC Formoso (resistant, donor parent) × BRS Pérola (susceptible, recurrent parent). Nine microsatellites (SSRs) and one Sequence Tagged Sites (STS) markers previously linked to ANT resistance were used to genotype this progeny, and the results showed that the selection of the genotypes closest to the donor parent in the BC1F1 population decreased the number of backcrossing cycles necessary to obtain advanced isogenic lines, potentiating the use of this tool for early selection of resistant cultivars. A total of 31 % of the BC1F1 progeny was selected and backcrossed again. The progeny derived from the second backcross (BC2F3) was selected for the Carioca grain ideotype, and 42 % of the genotypes showed high resistance to anthracnose under controlled conditions of infection for races 65 and 81. Superior resistant plants were selected and evaluated under natural conditions of infection to fusarium wilt and angular leaf spot, allowing the selection of two inbred lines with higher resistance to anthracnose, fusarium wilt, angular leaf spot and postharvest quality traits such as yield, 100 seed weight, L value at seed harvest grain darkening and cooking time. The approach outlined in this paper proved to be effective to simultaneously select for disease resistance without losing technological quality aspects of the bean.

Production of potato seed tubers under the effect of Trichoderma sp. and rhizobacteria in greenhouse conditions / Produção de tubérculos de batata-semente sob efeito de Trichoderma sp. e rizobactérias em casa de vegetação

Potato (Solanum tuberosum L.) is one of the main crops in the Andean region and due to environmental aspects, the use of biocontrol agents is considered a safe way to produce potato seed tubers.The objective of the study was to evaluate potato inoculation with Trichoderma sp. as a matrix and rhizobacteria Bacillus simplex and Azotobacter sp. on the growth of potato seedlings from in vitro culture, for the production of seed tubers in a greenhouse. The inoculation of microorganisms was carried out in pots, using five potato genotypes for processing. The inoculation treatments were: control, Trichoderma sp., Trichoderma sp. + Azotobacter sp., Trichoderma sp. + Bacillus simplex, Trichoderma sp. + B. simplex + Azotobacter sp. The potato genotypes were cv. Unica (CIP392797.22), cv. Bicentenaria, the advanced clones CIP 396311.1, CIP 399101.1, and the experimental clone UH-09 from the Universidad Nacional José Faustino Sánchez Carrión. A completely randomized design was used, under a factorial arrangement and comparisons between treatments were made at p<0.05. All inoculant treatments exceeded the control in number and weight of tubers per plant as well as in tuber size. Inoculations of Trichoderma sp. alone or with Azotobacter sp. increased plant height, number of leaves per plant and vegetative uniformity; inoculations with the Trichoderma sp. + B. simplex + Azotobacter sp. consortium, improved the dry weight of the foliage, number of shoots per plant and vegetative vigor. There were significant interactions between potato genotypes and inoculant treatments for plant uniformity, vegetative vigor, and the foliage's dry weight. Coinoculation with Trichoderma sp. and some bacterial strains promote the growth of in vitro potato seedlings, increasing the size and weight of the seed tubers and plant biomass, indicating an interrelation between fungi and bacteria that influence the production of potatoes in a greenhouse.(AU)

A batata (Solanum tuberosum L.) é uma das principais culturas da região andina e devido aos aspectos ambientais, o uso de agentes de biocontrole é considerado uma forma segura de produzir tubérculos de batata-semente. O objetivo do trabalho foi avaliar a inoculação de batata com Trichoderma sp. como matriz e rizobactérias Bacillus simplex e Azotobacter sp. sobre o crescimento de mudas de batata provenientes de cultivo in vitro, para produção de tubérculos-semente em casa de vegetação. A inoculação dos microrganismos foi realizada em vasos, utilizando-se cinco genótipos de batata para processamento. Os tratamentos de inoculação foram: testemunha, Trichoderma sp., Trichoderma sp. + Azotobacter sp., Trichoderma sp. + B.simplex, Trichoderma sp. + B.simplex + Azotobacter sp. Os genótipos de batata foram cv. Única (CIP392797.22), cv. Bicentenaria, os clones avançados CIP396311.1, CIP399101.1, e o clone experimental UH-9 da Universidade Nacional José Faustino Sánchez Carrión. O delineamento foi inteiramente casualizado, em esquema fatorial e as comparações entre os tratamentos foram feitas com p<0,05. Todos os tratamentos com inoculantes excederam o controle em número e peso de tubérculos por planta, bem como em tamanho de tubérculo. Inoculações de Trichoderma sp. sozinho ou com Azotobactersp. aumento da altura das plantas, número de folhas por planta e uniformidade vegetativa; inoculações com o Trichoderma sp. + B.simplex + Azotobacter sp. consorcio, melhorou a massa seca da folhagem, número de brotações por planta e vigor vegetativo. Houve interações significativas entre genótipos de batata e tratamentos inoculantes para uniformidade e vigor vegetativo, e para a massa seca da folhagem. Coinoculação com Trichoderma sp. e algumas cepas bacterianas promovem o crescimento de mudas de batata in vitro, aumentando o tamanho e o peso dos tubérculos-semente e da biomassa vegetal, indicando que existe inter-relação entre fungos e bactérias que influenciam a produção de batata em casa de vegetação.(AU)

Combining disease resistance and postharvest quality traits by early marker-assisted backcrossing in carioca beans

Common bean is a worldwide important crop. The development of varieties with durable resistance to diseases is a major challenge in common bean breeding. The present study aimed at evaluating the phenotypic and molecular selection of anthracnose resistance in a population obtained by assisted backcrossing from IAC Formoso (resistant, donor parent) × BRS Pérola (susceptible, recurrent parent). Nine microsatellites (SSRs) and one Sequence Tagged Sites (STS) markers previously linked to ANT resistance were used to genotype this progeny, and the results showed that the selection of the genotypes closest to the donor parent in the BC1F1 population decreased the number of backcrossing cycles necessary to obtain advanced isogenic lines, potentiating the use of this tool for early selection of resistant cultivars. A total of 31 % of the BC1F1 progeny was selected and backcrossed again. The progeny derived from the second backcross (BC2F3) was selected for the Carioca grain ideotype, and 42 % of the genotypes showed high resistance to anthracnose under controlled conditions of infection for races 65 and 81. Superior resistant plants were selected and evaluated under natural conditions of infection to fusarium wilt and angular leaf spot, allowing the selection of two inbred lines with higher resistance to anthracnose, fusarium wilt, angular leaf spot and postharvest quality traits such as yield, 100 seed weight, L value at seed harvest grain darkening and cooking time. The approach outlined in this paper proved to be effective to simultaneously select for disease resistance without losing technological quality aspects of the bean.

Combining disease resistance and postharvest quality traits by early marker-assisted backcrossing in carioca beans

Common bean is a worldwide important crop. The development of varieties with durable resistance to diseases is a major challenge in common bean breeding. The present study aimed at evaluating the phenotypic and molecular selection of anthracnose resistance in a population obtained by assisted backcrossing from IAC Formoso (resistant, donor parent) × BRS Pérola (susceptible, recurrent parent). Nine microsatellites (SSRs) and one Sequence Tagged Sites (STS) markers previously linked to ANT resistance were used to genotype this progeny, and the results showed that the selection of the genotypes closest to the donor parent in the BC1F1 population decreased the number of backcrossing cycles necessary to obtain advanced isogenic lines, potentiating the use of this tool for early selection of resistant cultivars. A total of 31 % of the BC1F1 progeny was selected and backcrossed again. The progeny derived from the second backcross (BC2F3) was selected for the Carioca grain ideotype, and 42 % of the genotypes showed high resistance to anthracnose under controlled conditions of infection for races 65 and 81. Superior resistant plants were selected and evaluated under natural conditions of infection to fusarium wilt and angular leaf spot, allowing the selection of two inbred lines with higher resistance to anthracnose, fusarium wilt, angular leaf spot and postharvest quality traits such as yield, 100 seed weight, L value at seed harvest grain darkening and cooking time. The approach outlined in this paper proved to be effective to simultaneously select for disease resistance without losing technological quality aspects of the bean.

Agronomic feasibility of wheat and triticale cultivars in the semiarid of Minas Gerais state, Brazil / Viabilidade agronômica de cultivares de trigo e triticale na região semiárida do estado de Minas Gerais, Brasil

The production of winter cereals is becoming increasingly important in Brazil, largely due to advanced techniques that enable considerable qualitative and quantitative gains. This is due to plant breeding under different soil and climate conditions combined with proper management. The present study aims to assess the agronomic feasibility of growing wheat and triticale cultivars with two sowing times in the semiarid region of northern Minas Gerais State, Brazil. The experiment was conducted in 2018 at the Instituto de Ciências Agrárias (Institute of Agricultural Sciences) of Universidade Federal de Minas Gerais, Montes Claros campus. A randomized block design was used, with four replications and an 8 × 2 factorial arrangement consisting of eight genotypes (six wheat and two triticale cultivars) and two sowing times (April 21 and May 12, 2018). The irrigated production of wheat and triticale was agronomically feasible in the semi-arid region of Minas Gerais state and sowing time affected the main agronomic traits of interest of winter cereals. However, it is essential to study the economic feasibility of the crop. Sowing in April was the most indicated for wheat and triticale, with IPR Potyporã, IPR 144 and IPR 111 as the recommended cultivars.Key words: Agronomic traits. Triticum. aestivum L. X Triticosecale wittimack. Winter cereals.

A produção brasileira de cereais de inverno está ganhando cada vez mais importância, principalmente pelo uso de técnicas avançadas, o que permite um ganho qualitativo e quantitativo considerável. Isso ocorre em função do melhoramento genético nas diferentes condições edafoclimáticas associado ao manejo adequado dessas plantas. Assim, esse trabalho objetivou avaliar a viabilidade agronômica de cultivares de trigo e triticale em duas épocas de semeadura na região semiárida do estado de Minas Gerais, Brasil. O experimento foi conduzido no delineamento de blocos casualizados com quatro repetições, em arranjo fatorial 8 × 2, composto por oito genótipos (6 cultivares de trigo e 2 cultivares de triticale) e duas épocas de semeadura (21 de abril e 12 de maio de 2018). A produção irrigada de trigo e triticale no semiárido mineiro foi agronomicamente viável, e a época de semeadura afetou as principais características de interesse agronômico dos cereais de inverno. Porém, é fundamental estudar a viabilidade econômica para a indicação da cultura. A semeadura em abril foi a mais indicada para trigo e triticale, nesse caso, recomenda-se o uso das cultivares IPR Potyporã, IPR 144 e IPR 111.

Performance of potato clones for processing in subtropical and high-altitude tropical regions of Brazil / Seleção de clones de batata para processamento em regiões do Brasil de clima subtropical e tropical de altitude

This work evaluated the performance of potato clones for some agronomic and processing traits, in subtropical and high-altitude tropical regions, under conventional and organic production systems. Experiments were conducted in spring of 2017 and 2018 in Canoinhas-SC (subtropical), under the conventional system, and in winter of 2018 and 2019 in Brasília-DF (tropical), Brazil, under conventional and organic systems. Eleven advanced clones and cultivars Agata (fresh), Atlantic (chipping) and Asterix (French fry) were evaluated. RCBD with tree replications was used, and tuber yield and processing traits, plant vigor and cycle were evaluated. It was not possible to select high yielding and good processing quality clones with short cycle and less vigorous plants. It because higher yield and larger tuber size were attained by longer cycle genotypes, which had higher specific gravity, but darker frying color. The most outstanding clones differed with region and production system. For chipping, in the subtropical region, no clone had adequate quality, but in tropical F177-11-20 presented similar processing traits and higher or similar yield to 'Atlantic' in both systems, and also ORG7785 in organic. Comparing with ‘Asterix, for French fry, in the subtropical region, superior or similar to the standard this cultiva rwere F129-10-06 and F163-11-01; while in the tropical region and conventional system, were the clones ORG7785, F129-10-06, F163-11-01, F177-11-20, ORG6464, ORG 6377, F05-11-03, Odone 80-02 and F174-11-01; and in organic system, the best clones were F54-11-03, ORG7785, F129-10-06, F163-11-01, F177-11-20 and ORG6464.(AU)

Neste trabalho foi avaliado o desempenho de clones de batata para caracteres agronômicos e de qualidade de processamento, em regiões subtropical e tropical de altitude, sob sistema convencional e orgânico de produção. Os experimentos foram conduzidos na primavera de 2017 e 2018 em Canoinhas-SC (subtropical), sobre sistema convencional, e nos invernos de 2018 e 2019 em Brasília-DF (tropical), Brasil, sob sistemas convencional e orgânico. Foram avaliados onze clones avançados e as cultivares Agata (mercado fresco), Atlantic (chips) e Asterix (palitos fritos). Foi utilizado delineamento em blocos casualisados com três repetições. Foram avaliados caracteres relacionados ao rendimento de tubérculos, qualidade de fritura, vigor de planta e ciclo vegetativo. Foi verificado que não foi possível selecionar clones com elevado rendimento de tubérculos e boa qualidade de fritura e com ciclo vegetativo precoce e com plantas menos vigorosas. Isso porque maior rendimento e maiores tamanhos de tubérculos foram associados com ciclo vegetativo mais longo, maior peso específico de tubérculos, porém cor mais escura de fritura. Os melhores clones diferiram com a região e sistemas de produção. Para chips, n aregião subtropical, nenhum clone apresentou bom desempenho, porém no ecossistema tropical, F177-11-20 apresentou similares qualidades industriais e maior ou superior produtividade em comparação com 'Atlantic' em ambos os sistemas de cultivo, também o clone ORG7785 no sistema orgânico. Para o mercado de fritura de palitos, portanto comparando com ‘Asterix, na região subtropical, os clones F129-10-06 eF163-11-01foram superiores ou equivalentes a esta cultivar; enquanto que na região tropical em sistema convencional destacam-se os clonesORG7785, F129-10-06, F163-11-01, F177-11-20, ORG6464, ORG 6377, F05-11-03, Odone 80-02 eF174-11-01; e nos sistema orgânico os clonesF54-11-03, ORG7785, F129-10-06, F163-11-01, F177-11-20 eORG6464.(AU)

Performance of potato clones for processing in subtropical and high-altitude tropical regions of Brazil / Seleção de clones de batata para processamento em regiões do Brasil de clima subtropical e tropical de altitude

This work evaluated the performance of potato clones for some agronomic and processing traits, in subtropical and high-altitude tropical regions, under conventional and organic production systems. Experiments were conducted in spring of 2017 and 2018 in Canoinhas-SC (subtropical), under the conventional system, and in winter of 2018 and 2019 in Brasília-DF (tropical), Brazil, under conventional and organic systems. Eleven advanced clones and cultivars Agata (fresh), Atlantic (chipping) and Asterix (French fry) were evaluated. RCBD with tree replications was used, and tuber yield and processing traits, plant vigor and cycle were evaluated. It was not possible to select high yielding and good processing quality clones with short cycle and less vigorous plants. It because higher yield and larger tuber size were attained by longer cycle genotypes, which had higher specific gravity, but darker frying color. The most outstanding clones differed with region and production system. For chipping, in the subtropical region, no clone had adequate quality, but in tropical F177-11-20 presented similar processing traits and higher or similar yield to 'Atlantic' in both systems, and also ORG7785 in organic. Comparing with ‘Asterix’, for French fry, in the subtropical region, superior or similar to the standard this cultiva rwere F129-10-06 and F163-11-01; while in the tropical region and conventional system, were the clones ORG7785, F129-10-06, F163-11-01, F177-11-20, ORG6464, ORG 6377, F05-11-03, Odone 80-02 and F174-11-01; and in organic system, the best clones were F54-11-03, ORG7785, F129-10-06, F163-11-01, F177-11-20 and ORG6464.

Neste trabalho foi avaliado o desempenho de clones de batata para caracteres agronômicos e de qualidade de processamento, em regiões subtropical e tropical de altitude, sob sistema convencional e orgânico de produção. Os experimentos foram conduzidos na primavera de 2017 e 2018 em Canoinhas-SC (subtropical), sobre sistema convencional, e nos invernos de 2018 e 2019 em Brasília-DF (tropical), Brasil, sob sistemas convencional e orgânico. Foram avaliados onze clones avançados e as cultivares Agata (mercado fresco), Atlantic (chips) e Asterix (palitos fritos). Foi utilizado delineamento em blocos casualisados com três repetições. Foram avaliados caracteres relacionados ao rendimento de tubérculos, qualidade de fritura, vigor de planta e ciclo vegetativo. Foi verificado que não foi possível selecionar clones com elevado rendimento de tubérculos e boa qualidade de fritura e com ciclo vegetativo precoce e com plantas menos vigorosas. Isso porque maior rendimento e maiores tamanhos de tubérculos foram associados com ciclo vegetativo mais longo, maior peso específico de tubérculos, porém cor mais escura de fritura. Os melhores clones diferiram com a região e sistemas de produção. Para chips, n aregião subtropical, nenhum clone apresentou bom desempenho, porém no ecossistema tropical, F177-11-20 apresentou similares qualidades industriais e maior ou superior produtividade em comparação com 'Atlantic' em ambos os sistemas de cultivo, também o clone ORG7785 no sistema orgânico. Para o mercado de fritura de palitos, portanto comparando com ‘Asterix’, na região subtropical, os clones F129-10-06 eF163-11-01foram superiores ou equivalentes a esta cultivar; enquanto que na região tropical em sistema convencional destacam-se os clonesORG7785, F129-10-06, F163-11-01, F177-11-20, ORG6464, ORG 6377, F05-11-03, Odone 80-02 eF174-11-01; e nos sistema orgânico os clonesF54-11-03, ORG7785, F129-10-06, F163-11-01, F177-11-20 eORG6464.

Reaction of sugarcane genotypes to brown and to orange rust by leaf whorl inoculation / Reação de genótipos de cana-de-açúcar às ferrugens marrom e alaranjada por inoculação no cartucho foliar

In this research eleven sugarcane genotypes were classified in relation to their resistance to brown rust, and eleven to their resistance to orange rust. Artificial inoculation was carried out in the leaf whorl of 165-day-old plants in the city of Paranavaí, Paraná State, Brazil, in 2017. The evaluation was performed 30 days after inoculation, using a rating scale. Among the genotypes tested for brown rust, four were classified as susceptible, six as moderately susceptible and one presented moderate resistance. For orange rust, three genotypes were classified as susceptible, seven as moderately susceptible and one as moderately resistant. The evaluation and classification of the reaction of sugarcane genotypes to the rusts is an important tool that assist in preliminary trials and selection of promising genotypes for more advanced stages of breeding programs and provides information to producers on the choice of cultivars to be planted.(AU)

Neste trabalho onze genótipos de cana-de-açúcar foram classificados em relação à sua resistência à ferrugem marrom, e onze quanto à resistência à ferrugem alaranjada. Foi realizada a inoculação no cartucho foliar de colmos com 165 dias, no município de Paranavaí, PR, em 2017. A avaliação foi feita aos 30 dias após a inoculação, utilizando uma escala de notas. Dos genótipos avaliados para ferrugem marrom, quatro foram classificados como suscetíveis, seis como moderadamente suscetíveis e um apresentou resistência moderada. Para a ferrugem alaranjada, três genótipos foram classificados como suscetíveis, sete como moderadamente suscetíveis e um como moderadamente resistente. A avaliação e classificação da reação de genótipos de cana-de-açúcar às ferrugens é uma ferramenta importante que auxilia em ensaios preliminares, na escolha de genótipos promissores para fases mais avançadas dos programas de melhoramento além de fornecer informações aos produtores na seleção das cultivares que serão plantadas.(AU)

Productive and qualitative characteristics of strawberry genotypes in the Plateau of the State of Santa Catarina, Brazil / Características produtivas e qualitativas de genótipos de morangueiro no Planalto Catarinense

To produce strawberries on a commercial scale, it is necessary to choose the cultivars best adapted to the growing site. This work aimed to compare strawberry genotypes regarding production and fruit quality, in the municipality of Lages, State of Santa Catarina, Brazil, during the 2017/2018 harvest season. In this work, 15 genotypes were evaluated, five commercial cultivars and ten advanced selections. The experimental design was in randomized blocks, with four replicates and plots of 11 plants. The cultivation system used was in the soil of an open field, in beds of approximately 90 centimeters, with three rows per bed. Planting distance was of 30 centimeters between rows and plants. The Sabrina cultivar showed the highest production (1,231.77 g plant-1) and number of fruits (78.48 fruits plant-1). The highest quality fruits were obtained from the selections FRF PIR 256.4, FRF 104.1, FRF 57.6, FRF LAM 119.1 and cultivar Pircinque, characterized by soluble solids/titratable acidity ratios above 15. In the productive cycle in question, cultivar Sabrina presented the best performance, demonstrating the potential for recommendation to the producers of the South Plateau of State of Santa Catarina.

Para produzir morangos em escala comercial, é necessário escolher as cultivares melhor adaptadas ao local de cultivo. Objetivou-se com este trabalho confrontar genótipos de morangueiro quanto a aspectos de produção e qualidade de frutos, no município de Lages, em Santa Catarina, no ciclo agrícola 2017/2018. Foram avaliados 15 genótipos, sendo cinco cultivares comerciais e dez seleções avançadas. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, e parcelas constituídas por 11 plantas. O sistema de cultivo utilizado foi no solo, em campo aberto, em canteiros com aproximadamente 90 centímetros de largura, com três linhas de plantio por canteiro. A distância de plantio foi de 30 centímetros, entre fileiras e plantas. A cultivar Sabrina obteve a maior produção (1.231,77 g planta-1) e número de frutos (78,48 frutos planta-1). Com as seleções FRF PIR 256.4, FRF 104.1, FRF 57.6, FRF LAM 119.1 e a cultivar Pircinque se obtiveram os frutos de qualidade superior, caracterizados por médias acima de 15 para a relação sólidos solúveis / acidez titulável. No ciclo produtivo em questão, a cultivar Sabrina apresentou o melhor desempenho, demonstrando potencial para ser recomendada aos produtores da região do Planalto Sul Catarinense.

Productive and qualitative characteristics of strawberry genotypes in the Plateau of the State of Santa Catarina, Brazil / Características produtivas e qualitativas de genótipos de morangueiro no Planalto Catarinense

To produce strawberries on a commercial scale, it is necessary to choose the cultivars best adapted to the growing site. This work aimed to compare strawberry genotypes regarding production and fruit quality, in the municipality of Lages, State of Santa Catarina, Brazil, during the 2017/2018 harvest season. In this work, 15 genotypes were evaluated, five commercial cultivars and ten advanced selections. The experimental design was in randomized blocks, with four replicates and plots of 11 plants. The cultivation system used was in the soil of an open field, in beds of approximately 90 centimeters, with three rows per bed. Planting distance was of 30 centimeters between rows and plants. The Sabrina cultivar showed the highest production (1,231.77 g plant-1) and number of fruits (78.48 fruits plant-1). The highest quality fruits were obtained from the selections FRF PIR 256.4, FRF 104.1, FRF 57.6, FRF LAM 119.1 and cultivar Pircinque, characterized by soluble solids/titratable acidity ratios above 15. In the productive cycle in question, cultivar Sabrina presented the best performance, demonstrating the potential for recommendation to the producers of the South Plateau of State of Santa Catarina.(AU)

Para produzir morangos em escala comercial, é necessário escolher as cultivares melhor adaptadas ao local de cultivo. Objetivou-se com este trabalho confrontar genótipos de morangueiro quanto a aspectos de produção e qualidade de frutos, no município de Lages, em Santa Catarina, no ciclo agrícola 2017/2018. Foram avaliados 15 genótipos, sendo cinco cultivares comerciais e dez seleções avançadas. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições, e parcelas constituídas por 11 plantas. O sistema de cultivo utilizado foi no solo, em campo aberto, em canteiros com aproximadamente 90 centímetros de largura, com três linhas de plantio por canteiro. A distância de plantio foi de 30 centímetros, entre fileiras e plantas. A cultivar Sabrina obteve a maior produção (1.231,77 g planta-1) e número de frutos (78,48 frutos planta-1). Com as seleções FRF PIR 256.4, FRF 104.1, FRF 57.6, FRF LAM 119.1 e a cultivar Pircinque se obtiveram os frutos de qualidade superior, caracterizados por médias acima de 15 para a relação sólidos solúveis / acidez titulável. No ciclo produtivo em questão, a cultivar Sabrina apresentou o melhor desempenho, demonstrando potencial para ser recomendada aos produtores da região do Planalto Sul Catarinense.(AU)

Nutritive value of improved populations Brachiaria ruziziensis / Valor nutritivo de populações melhoradas de Brachiaria ruziziensis

A low number of Brachiaria ruziziensis (Syn. Urochloa) cultivars available on the market and a lack of information about its forage potential have made it difficult to expand its cultivated area, and have therefore made it necessary to implement a breeding program for this species. Thus, the objective of this work was to evaluate the nutritional value of ten improved populations of Brachiaria ruziziensis (Syn. Urochloa) and two controls (B. ruziziensis cv. Kennedy and B. brizantha cv. Marandu). The experimental design was a randomized block design with three replications in five sections. The data were submitted to analysis of variance in the subdivided plot in which the primary factors were the populations and the secondary cuts. The Tukey test was used at 5% of significance for the comparison of means. The genotypes used came from the third recurrent selection cycle of Embrapa dairy cattle, originating from the interbreeding of clones which had been identified as superior. The height of the cuts was 10 cm in relation to the ground. The material was cut and weighed in the field to obtain the sample weights to determine the nutritional forage value. After drying, the samples were ground in 1 mm sieves for chemical analyzes and in vitro digestibility. The best CP, ADF and NDF levels observed in IV populations (lower levels of ADF and NDF at 93 days of cut interval and lower NDF contents at 35 and 41 days of cut interval), population VI (higher CP content in the interval of 93 days, lower DM content at 64 and 93 days of cut interval, and lower NDF content at 35 and 64 days of cut interval) showed that these populations can be evaluated under grazing even at an advanced maturation stage. The objective of these selections was to evaluate the nutritional value of improved populations of Brachiaria ruziziensis (Syn. Urochloa) in order to obtain more homogeneous populations for implantation of grazing experiments.

O reduzido número de cultivares de Brachiaria ruziziensis (Syn. Urochloa) disponíveis no mercado, a ausência de informações sobre seu potencial forrageiro que vem dificultando a expansão de sua área cultivada tornaram necessário a implantação de um programa de melhoramento genético desta espécie. O objetivo do trabalho foi avaliar o valor nutricional de dez populações melhoradas e duas testemunhas (B. ruziziensis cv. Kennedy e B. brizantha cv. Marandu). O delineamento experimental utilizado foi o de blocos ao acaso com três repetições, em cinco cortes. Os dados foram submetidos à análise de variância conjunta no esquema de parcela subdividida no qual o fator primário foram as populações e o secundário os cortes. Para a comparação das médias utilizou-se o teste de Tukey a 5% de significância. Os genótipos utilizados foram provenientes do terceiro ciclo de seleção recorrente na Embrapa Gado de Leite, originadas do intercruzamento de clones identificados como superiores. A altura dos cortes foi de 10 cm em relação ao solo. O material foi cortado e pesado em campo para obtenção dos pesos das amostras para realização das avaliações do valor nutritivo da forragem. Após a secagem, procedeu-se a moagem das amostras em peneira de 1 mm para realização das análises químicas e digestibilidade in vitro. Os melhores teores de PB, FDA e FDN observados nas populações IV (menores teores de FDA e FDN aos 93 dias de intervalo de corte e menores teores de FDN aos 35 e 41 dias de intervalo), população VI (maior teor de PB no intervalo de corte de 93 dias, menor teor de FDA aos 64 e 93 dias de intervalo de corte e menor teor de FDN aos 35 e 64 dias de intervalo de corte) demonstram que mesmo em avançado estágio de maturação essas populações podem ser avaliadas sob pastejo. O objetivo dessas seleções foi avaliar o valor nutricional de populações melhoradas de Brachiaria ruziziensis (Syn. Urochloa) visando obter populações mais homogêneas para...

Nutritive value of improved populations Brachiaria ruziziensis / Valor nutritivo de populações melhoradas de Brachiaria ruziziensis

A low number of Brachiaria ruziziensis (Syn. Urochloa) cultivars available on the market and a lack of information about its forage potential have made it difficult to expand its cultivated area, and have therefore made it necessary to implement a breeding program for this species. Thus, the objective of this work was to evaluate the nutritional value of ten improved populations of Brachiaria ruziziensis (Syn. Urochloa) and two controls (B. ruziziensis cv. Kennedy and B. brizantha cv. Marandu). The experimental design was a randomized block design with three replications in five sections. The data were submitted to analysis of variance in the subdivided plot in which the primary factors were the populations and the secondary cuts. The Tukey test was used at 5% of significance for the comparison of means. The genotypes used came from the third recurrent selection cycle of Embrapa dairy cattle, originating from the interbreeding of clones which had been identified as superior. The height of the cuts was 10 cm in relation to the ground. The material was cut and weighed in the field to obtain the sample weights to determine the nutritional forage value. After drying, the samples were ground in 1 mm sieves for chemical analyzes and in vitro digestibility. The best CP, ADF and NDF levels observed in IV populations (lower levels of ADF and NDF at 93 days of cut interval and lower NDF contents at 35 and 41 days of cut interval), population VI (higher CP content in the interval of 93 days, lower DM content at 64 and 93 days of cut interval, and lower NDF content at 35 and 64 days of cut interval) showed that these populations can be evaluated under grazing even at an advanced maturation stage. The objective of these selections was to evaluate the nutritional value of improved populations of Brachiaria ruziziensis (Syn. Urochloa) in order to obtain more homogeneous populations for implantation of grazing experiments.(AU)

O reduzido número de cultivares de Brachiaria ruziziensis (Syn. Urochloa) disponíveis no mercado, a ausência de informações sobre seu potencial forrageiro que vem dificultando a expansão de sua área cultivada tornaram necessário a implantação de um programa de melhoramento genético desta espécie. O objetivo do trabalho foi avaliar o valor nutricional de dez populações melhoradas e duas testemunhas (B. ruziziensis cv. Kennedy e B. brizantha cv. Marandu). O delineamento experimental utilizado foi o de blocos ao acaso com três repetições, em cinco cortes. Os dados foram submetidos à análise de variância conjunta no esquema de parcela subdividida no qual o fator primário foram as populações e o secundário os cortes. Para a comparação das médias utilizou-se o teste de Tukey a 5% de significância. Os genótipos utilizados foram provenientes do terceiro ciclo de seleção recorrente na Embrapa Gado de Leite, originadas do intercruzamento de clones identificados como superiores. A altura dos cortes foi de 10 cm em relação ao solo. O material foi cortado e pesado em campo para obtenção dos pesos das amostras para realização das avaliações do valor nutritivo da forragem. Após a secagem, procedeu-se a moagem das amostras em peneira de 1 mm para realização das análises químicas e digestibilidade in vitro. Os melhores teores de PB, FDA e FDN observados nas populações IV (menores teores de FDA e FDN aos 93 dias de intervalo de corte e menores teores de FDN aos 35 e 41 dias de intervalo), população VI (maior teor de PB no intervalo de corte de 93 dias, menor teor de FDA aos 64 e 93 dias de intervalo de corte e menor teor de FDN aos 35 e 64 dias de intervalo de corte) demonstram que mesmo em avançado estágio de maturação essas populações podem ser avaliadas sob pastejo. O objetivo dessas seleções foi avaliar o valor nutricional de populações melhoradas de Brachiaria ruziziensis (Syn. Urochloa) visando obter populações mais homogêneas para...(AU)

Imputation of genetic composition for missing pedigree data in Serrasalmidae using morphometric data

This study aimed to impute the genetic makeup of individual fishes of Serrasalmidae family on the basis of body weight and morphometric measurements. Eighty-three juveniles, belonging to the genetic groups Pacu, Pirapitinga, Tambaqui, Tambacu, Tambatinga, Patinga, Paqui and Piraqui, were separated into 16 water tanks in a recirculation system, with two tanks per genetic group, where they remained until they reached 495 days of age. They were then weighed and analyzed according to the following morphometric parameters: Standard Length (SL), Head Length (HL), Body Height (BH), and Body Width (BW). The identity of each fish was confirmed with two SNPs and two mitochondrial markers. Two analyses were performed: one for the validating the imputation and another for imputing a genetic composition of animals considered to be advanced hybrids (post F1). In both analyses, we used linear mixed models with a mixture of normal distributions to impute the genetic makeup of the fish based on phenotype. We applied the mixed models method, whereby the environmental effects were estimated by the Empirical Best Linear Unbiased Estimator (EBLUE) and genetic effects are considered random, obtaining the Empirical Best Linear Unbiased Predictor (EBLUP) from the general (GCA) and the specific (SCA) combining ability effects. The results showed that validation of the genetic makeup imputation based on body weight can be used because of the strong correlation between the observed and imputed genotype. The fish classified as advanced hybrids had a genetic composition with a high probability of belonging to known genotypes and there was consistency in genotype imputation according to the different characteristics used.

Imputation of genetic composition for missing pedigree data in Serrasalmidae using morphometric data

This study aimed to impute the genetic makeup of individual fishes of Serrasalmidae family on the basis of body weight and morphometric measurements. Eighty-three juveniles, belonging to the genetic groups Pacu, Pirapitinga, Tambaqui, Tambacu, Tambatinga, Patinga, Paqui and Piraqui, were separated into 16 water tanks in a recirculation system, with two tanks per genetic group, where they remained until they reached 495 days of age. They were then weighed and analyzed according to the following morphometric parameters: Standard Length (SL), Head Length (HL), Body Height (BH), and Body Width (BW). The identity of each fish was confirmed with two SNPs and two mitochondrial markers. Two analyses were performed: one for the validating the imputation and another for imputing a genetic composition of animals considered to be advanced hybrids (post F1). In both analyses, we used linear mixed models with a mixture of normal distributions to impute the genetic makeup of the fish based on phenotype. We applied the mixed models method, whereby the environmental effects were estimated by the Empirical Best Linear Unbiased Estimator (EBLUE) and genetic effects are considered random, obtaining the Empirical Best Linear Unbiased Predictor (EBLUP) from the general (GCA) and the specific (SCA) combining ability effects. The results showed that validation of the genetic makeup imputation based on body weight can be used because of the strong correlation between the observed and imputed genotype. The fish classified as advanced hybrids had a genetic composition with a high probability of belonging to known genotypes and there was consistency in genotype imputation according to the different characteristics used.(AU)

Qualidade da carne de cordeiros: genótipo e manejo nutricional / Lamb meat quality: genotype and nutritional handling

Diversos fatores relacionados ao animal (peso, idade, sexo, genótipo) e ao ambiente (alimentação, sistema de criação, estresse pré-abate, refrigeração, congelamento, tipos de embalagem) afetam os parâmetros de qualidade de carne. A raça parece influenciar a maciez, coloração, teor de gordura intramuscular e composição em minerais e gordura, enquanto o manejo alimentar (pastagem, confinamento, relação volumoso:concentrado, uso de aditivos e antioxidantes) influenciam nas características físico-químicas, qualidade sensorial e perfil de ácidos graxos da carne. A produção de carne ovina no Brasil tem avançado nos últimos anos, mas ainda não é suficiente para abastecer o mercado interno, nem em quantidade nem em qualidade. Não há um sistema padrão para criação de ovinos que seja ideal para todas as regiões do país, sendo necessário considerar as diferenças entre clima, disponibilidade de alimentos e genótipos. No entanto, todos os sistemas buscam produzir animais que ofereçam carne de qualidade. Considerando que nos últimos anos a população tem buscado consumir alimentos mais saudáveis, com reduzidos teores de gordura e colesterol, e que a carne é uma das principais fontes de gordura dos seres humanos, o estudo dos fatores que possam influenciar sua composição e seus parâmetros qualitativos é de relevada importância. Esta revisão tem como objetivo abordar os principais aspectos relacionados à influência dos genótipos e do manejo nutricional sobre a qualidade da carne de cordeiros.

Several factors related to the animal (weight, age, gender, genotype) and the environment (food, farming system, pre-slaughter stress, chilling, freezing, packaging types) affect the meat quality parameters. The breed appears to influence the softness, color, intramuscular fat content and composition in minerals and fat while feeding management (pasture, feedlot, roughage: concentrate, use of additives and antioxidants) influence the physical and chemical characteristics, sensory quality and profile of meat fatty acid. The production of sheep meat in Brazil has advanced in recent years, but still not enough to supply the domestic market or in quantity or in quality. There is no standard system for sheep that is ideal for all regions of the country, being necessary to consider the differences in climate, food availability and genotypes. However, all systems seek to produce animals that provide quality meat. Whereas in recent years the population has sought to consume healthier foods with reduced fat and cholesterol levels, and the meat is a major source of fat in humans, the study of the factors that may influence its composition and qualitative parameters it is of high importance. This review aims to address the main issues of the influence of genotype and nutritional management on the quality of lamb meat.

Qualidade da carne de cordeiros: genótipo e manejo nutricional / Lamb meat quality: genotype and nutritional handling

Diversos fatores relacionados ao animal (peso, idade, sexo, genótipo) e ao ambiente (alimentação, sistema de criação, estresse pré-abate, refrigeração, congelamento, tipos de embalagem) afetam os parâmetros de qualidade de carne. A raça parece influenciar a maciez, coloração, teor de gordura intramuscular e composição em minerais e gordura, enquanto o manejo alimentar (pastagem, confinamento, relação volumoso:concentrado, uso de aditivos e antioxidantes) influenciam nas características físico-químicas, qualidade sensorial e perfil de ácidos graxos da carne. A produção de carne ovina no Brasil tem avançado nos últimos anos, mas ainda não é suficiente para abastecer o mercado interno, nem em quantidade nem em qualidade. Não há um sistema padrão para criação de ovinos que seja ideal para todas as regiões do país, sendo necessário considerar as diferenças entre clima, disponibilidade de alimentos e genótipos. No entanto, todos os sistemas buscam produzir animais que ofereçam carne de qualidade. Considerando que nos últimos anos a população tem buscado consumir alimentos mais saudáveis, com reduzidos teores de gordura e colesterol, e que a carne é uma das principais fontes de gordura dos seres humanos, o estudo dos fatores que possam influenciar sua composição e seus parâmetros qualitativos é de relevada importância. Esta revisão tem como objetivo abordar os principais aspectos relacionados à influência dos genótipos e do manejo nutricional sobre a qualidade da carne de cordeiros.(AU)

Several factors related to the animal (weight, age, gender, genotype) and the environment (food, farming system, pre-slaughter stress, chilling, freezing, packaging types) affect the meat quality parameters. The breed appears to influence the softness, color, intramuscular fat content and composition in minerals and fat while feeding management (pasture, feedlot, roughage: concentrate, use of additives and antioxidants) influence the physical and chemical characteristics, sensory quality and profile of meat fatty acid. The production of sheep meat in Brazil has advanced in recent years, but still not enough to supply the domestic market or in quantity or in quality. There is no standard system for sheep that is ideal for all regions of the country, being necessary to consider the differences in climate, food availability and genotypes. However, all systems seek to produce animals that provide quality meat. Whereas in recent years the population has sought to consume healthier foods with reduced fat and cholesterol levels, and the meat is a major source of fat in humans, the study of the factors that may influence its composition and qualitative parameters it is of high importance. This review aims to address the main issues of the influence of genotype and nutritional management on the quality of lamb meat.(AU)

TÉCNICAS MULTIVARIDAS ASSISTIDA POR FERRAMENTAS MOLECULARES NA CLASSIFICAÇÃO DE SERRASALMIDEOS

O presente trabalho objetivou-se avaliar modelos multivariados na imputação da composição genética de peixes Serrasalmidae com base no peso corporal em medidas morfométricas do corpo. Foram adquiridos 96 juvenis de duas pisciculturas comerciais, sendo 12 de cada grupo genético: pacu, pirapitinga, tambaqui, tambacu, tambatinga, patinga, paqui e piraqui. Os animais foram distribuídos aleatoriamente em 16 caixas dágua em sistema de recirculação, sendo duas caixas por grupo genético com densidade de seis animais por caixa, e foram cultivados até 495 dias de idade, sendo pesados e submetidos à análise morfométrica. Para confirmação da identidade dos animais foram utilizados dois marcadores nucleares e um mitocondrial. Para os animais que foram considerados híbridos avançados (pós-F1) pela análise molecular, foi utilizada a metodologia de modelos mistos de misturas multivariados para imputar a composição genética dos animais com base no peso corporal e nas medidas morfométricas. Utilizou-se a metodologia proposta por Griffing (1956), considerando o modelo misto, em que os efeitos ambientais foram estimados através dos EBLUE, e os efeitos genéticos foram considerados como aleatórios, sendo obtidos os EBLUP dos efeitos gerais e específicos de combinações. Para verificar a concordância da composição genética dos animais obtida via imputação, e a conhecida para as características avaliadas e entre estas, foi realizada a correlação de Pearson utilizando o teste de Mantel. Houve diferença na correlação entre os genótipos verdadeiros e os imputados entre as variáveis utilizadas nos diferentes modelos (uni e multicaráter). Observou-se que com acréscimo de variáveis morfométricas, elevou-se consideravelmente a correlação para a maioria das características, isso devido alta correlação genética e herdabilidade dessas variáveis, melhorando a acurácia de predição da composição genética desses indivíduos. Através da imputação foi possível fazer inferência sobre a composição genética dos animais para as diferentes metodologias e combinação das variáveis.

The present research was carried out to impute the genetic composition for missing pedigree data in Serrasalmideos based on body weight and morphometric measurements. A total of 96 juveniles were purchased from two commercial fish farms, 12 of each of the following genetic groups: pacu, pirapitinga, tambaqui, tambacu, tambatinga, patinga, paqui and piraqui. The animals were randomly distributed in 16 water boxes in a recirculation system, two boxes per genetic group and six animals per box density, where they were grown up to 495 days old, being weighed and submitted to morphometric analysis. Two nuclear and one mitochondrial markers were used to confirm the animals identity. For the animals that were considered advanced hybrids (post-F1) by molecular analysis, the mixed models methodology of multivariate mixtures was used to impute the kinship of the animals based on body weight and morphometric measurements. The Griffing (1956) methodology was used, considering the mixed model where the environmental effects were estimated through the EBLUE and the genetic effects were considered as random, obtaining the EBLUP of general and specific effects of combinations. In order to verify the genetic composition concordance of animals obtained via imputation and the known one for the characteristics evaluated and among them, the Pearson correlation was performed using the Mantel test. There was a difference in the correlation between the true and imputed genotypes among the variables used in different models (uni and multicaracter). It was observed that, with the morphometric variables addition, the correlation for most of the characteristics was elevated considerably, due to the high genetic correlation and heritability of these variables, and in this way, they had better explain the genetic composition of these individuals. Through imputation it was possible to make inferences about animals genetic composition for different methodologies and variables combination.

Growth regulators and darkness increase efficiency in in vitro culture of immature embryos from peppers

Common pepper (Capsicum annuum L.) is one of the most important vegetables in the world, and extensive breeding efforts are being made to develop new improved strains of this species. In this regard, in vitro culture of immature embryos may help breeders accelerate breeding cycles and overcome interspecific barriers, among other applications. In this study, we have optimized a protocol for in vitro culture of immature embryos of C. annuum. Levels of indole-3-acetic acid (IAA) and zeatin have been tested to improve the efficiency (germination rates) of this technique in C. annuum embryos at the four main immature stages (i.e. globular, heart, torpedo, and early cotyledonary) from four varietal types of this species (California Wonder, Piquillo, Guindilla, and Bola). The effect of 5-day initial incubation in the dark was also tested on the most efficient hormone formulation. On average, relatively low levels of both IAA and zeatin (0.01 mg L¹ each) (M1) provided the highest germination rates, particularly in the advanced stages (torpedo and cotyledonary). To a lesser extent, the lack of these growth regulators (M0) or high IAA (0.2 mg L¹)/low zeatin (0.01 mg L¹) (M2) combination also had a positive response. On the contrary, high zeatin levels (0.2 mg L¹) produced very low germination rates or callus development (efficiency 0-7 %). Different responses were also found between genotypes. Thus, considering the best media (M0, M1, M2), Bola embryos had the highest rates. M1 plus 5-days of initial dark incubation (M1-D) improved the efficiency rates at all embryo stages, particularly in the earliest (globular) embryos which increased from 3 % to > 20 %.

Growth regulators and darkness increase efficiency in in vitro culture of immature embryos from peppers

Common pepper (Capsicum annuum L.) is one of the most important vegetables in the world, and extensive breeding efforts are being made to develop new improved strains of this species. In this regard, in vitro culture of immature embryos may help breeders accelerate breeding cycles and overcome interspecific barriers, among other applications. In this study, we have optimized a protocol for in vitro culture of immature embryos of C. annuum. Levels of indole-3-acetic acid (IAA) and zeatin have been tested to improve the efficiency (germination rates) of this technique in C. annuum embryos at the four main immature stages (i.e. globular, heart, torpedo, and early cotyledonary) from four varietal types of this species (California Wonder, Piquillo, Guindilla, and Bola). The effect of 5-day initial incubation in the dark was also tested on the most efficient hormone formulation. On average, relatively low levels of both IAA and zeatin (0.01 mg L¹ each) (M1) provided the highest germination rates, particularly in the advanced stages (torpedo and cotyledonary). To a lesser extent, the lack of these growth regulators (M0) or high IAA (0.2 mg L¹)/low zeatin (0.01 mg L¹) (M2) combination also had a positive response. On the contrary, high zeatin levels (0.2 mg L¹) produced very low germination rates or callus development (efficiency 0-7 %). Different responses were also found between genotypes. Thus, considering the best media (M0, M1, M2), Bola embryos had the highest rates. M1 plus 5-days of initial dark incubation (M1-D) improved the efficiency rates at all embryo stages, particularly in the earliest (globular) embryos which increased from 3 % to > 20 %.(AU)

MANGALARGA MARCHADOR: ESTUDO MORFOMÉTRICO, CINEMÁTICO E GENÉTICO DA MARCHA BATIDA E DA MARCHA PICADA

Considerando a importância nacional da raça Mangalarga Marchador (MM) e sua crescente internacionalização, estudos que avaliam diferentes aspectos de seus andamentos singulares, marcha batida (MB) e marcha picada (MP), são necessários. Os objetivos desse estudo foram descrever e comparar as variáveis cinemáticas (VCine) da MB e da MP e verificar associações entre as medidas morfométricas e as VCine de equinos da raça MM; avaliar a influência do alelo mutante do DMRT3 em homozigose (AA) ou heterozigose (AC) no padrão de movimento da MP; identificar, por meio de estudo amplo de associação do genoma (GWAS), polimorfismos de nucleotídeo único (SNPs) e regiões genômicas que contenham possíveis genes responsáveis pelo fenótipo da MB na raça MM. Para análise cinemática, dezoito câmeras optoeletrônicas (240 Hz) foram posicionadas para a aquisição dos dados tridimensionais de três marcadores retrorreflexivos fixados no casco. Determinou-se duração, comprimento, frequência e velocidade de cada passada; dissociação relativa diagonal de decolagem e de apoio; e distribuição do tempo da passada em cada tipo de apoio (quadrupedal, tríplice, bipedal, monopedal e suspensão). Quarenta e oito cavalos pertencentes aos dois grupos de andamentos distintos: MP com genótipo AA e AC do SNP 22999655C>A (n=20) e MB com genótipo CC (n=28) foram analisados por meio do Equine SNP70 BeadChip e em seguida realizado GWAS. Para caracterização cinemática dos andamentos, os dados foram submetidos à analise descritiva. Para comparação entre fêmeas e machos e para comparação entre MB e MP, os tempos de apoio foram comparados pelo teste U de Mann-Whitney e as demais variáveis analisadas pelo teste t de Student (P0,05). A relação entre variáveis morfométricas e cinemáticas foi avaliada por correlação de Pearson. As variáveis cinemáticas temporais dos cavalos de MP de genótipo AA (n=9) e AC (n=9) foram comparadas por ANAVA de dois fatores (genótipo e passada, sendo a última de amostras repetidas) e em seguida teste de Tukey (P0,05). MB em velocidade média de 13,22 km/h apresentou maior porcentagem de apoios bipedal diagonal, seguida de monopedal pélvico, tríplice torácico, bipedal lateral e bipedal pélvico. Também foi identificada dissociação de apoio positiva que provavelmente está relacionada à manifestação de apoios monopedais e bipedais pélvicos. A MP na velocidade média de 12,68 km/h apresentou predomínio de apoios laterais seguidos por diagonais, tríplice torácico e monopedal pélvico. Na mesma velocidade, MP apresentou menor duração, comprimento e maior frequência de passadas; maior dissociação e ocorrência de apoios laterais e tríplices; e menor frequência de apoios diagonais, bipedais pélvicos e suspensão em relação à MB. Na amostra estudada, tanto na MB quanto na MP, os exemplares proporcionalmente maiores e com ângulos escapuloumeral, metacarpofalângico, coxofemoral, tibiotarsicometatársico menores apresentaram maior comprimento de passada e melhor distribuição dos tempos de apoio de acordo com Padrão da raça MM. Foi encontrada relação entre o padrão de andamento e os diferentes genótipos do DMRT3 (AA ou AC) na MP de equinos montados da raça MM. Indivíduos AC tiveram menor dissociação diagonal de decolagem e apresentaram maior proporção de apoio diagonal e, por isso, parecem apresentar distribuição de tempos de apoio mais próximo ao descrito como ideal no Padrão da raça quando comparados aos indivíduos AA. Os resultados do GWAS revelaram que, ao contrário do fenótipo de MP que é aparentemente determinado por gene único (DMRT3), a MB parece ser controlada por maior número de genes. Concluiu-se que morfometria e aspectos genéticos interferem no padrão de andamento de equinos de marcha batida ou picada da raça Mangalarga Marchador.

Considering the national significance of the Mangalarga Marchador (MM) breed and its increasing internationalization, studies that evaluate different aspects of their singular gaits, marcha batida (MB) and marcha picada (MP) are necessary. The objectives of this study were to describe and compare the kinematic variables (VCine) of MB and MP and to verify associations between the morphometric measurements and the VCine of MM horses; to evaluate the influence of the mutant allele of DMRT3 on homozygous (AA) or heterozygosis (AC) in the MP movement pattern; to identify, through genome-wide association study (GWAS), single nucleotide polymorphisms (SNPs) and genomic regions containing possible genes responsible for the phenotype of the MB in MM breed. For kinematic analysis, eighteen optoelectronic cameras (240 Hz) were positioned to acquire the three-dimensional data of three retroreflective markers fixed to the hooves. Duration, length, frequency and speed of each stride; diagonal advanced placement and lift-off and support phases (quadrupedal, tripedal, bipedal, Monopedal and suspension) were determined. Forty-eight horses belonging to the two gait groups, MP with AA and AC genotypes of the 22999655C>A SNP (n = 20) and MB with CC genotype (n = 28), were analyzed using the Equine SNP70 BeadChip and then performed GWAS. For kinematic characterization of the gaits, the data were submitted to descriptive analysis. For comparison between females and males, and for comparison between MB and MP, the support phases were compared by the Mann-Whitney U test and the other variables analyzed by Student's t-test (P 0.05). The relationship between morphometric and kinematic variables was evaluated by Pearson correlation. The temporal kinematic variables of MP horses of genotype AA (n = 9) and AC (n = 9) were compared by two-way ANOVA (genotype and stride, being the last of repeated samples) and then Tukey's test (P0.05). MB at the average speed of 13.22 km.h-1 presented higher percentage of diagonal bipedal support, followed by a single pelvic limb, triple thoracic limb, lateral bipedal and bipedal pelvic limbs. In MB, a positive diagonal advanced placement was also identified that is probably related to the manifestation of single-support and pelvic bipedal supports. MP at the average speed of 12.68 km.h-1 presented predominance of lateral supports followed by diagonals, triple of thoracic limb and single support of pelvic limb. At the same speed, MP horses presented shorter duration, shorter length and greater frequency of strides, greater dissociation and greater occurrence of lateral and triple supports, and lower frequency of diagonal supports, bipedal pelvic and suspension in relation to MB. In the studied sample, both MB and MP, the proportionally larger horses with smaller scapulohumeral, metacarpophalangeal, coxofemoral and tibiotarsometatarsal angles showed greater stride length and better distribution of support phases according to breed standard. Was found a relationship between the gait pattern and the different genotypes of DMRT3 (AA or AC) in the MP of ridden MM horses. AC individuals had lower diagonal advanced at lift-off and presented greater proportion of diagonal supports and therefore appeared to present distribution of support phases closer to that described as ideal in breed standard when compared to AA subjects. The GWAS results revealed that, unlike the MP phenotype that is apparently determined by single gene (DMRT3) in which the A allele of g.22999655C> A controls the characteristic, MB seems to be controlled by a greater number of genes. It was concluded that morphometry and genetic aspects interfere with the gait pattern of MB or MP Mangalarga Marchador horses.