Resumo
Selection for heading date has been a decisive factor to increase areas cropped with oats in Brazil. Although important to oat breeders, genomic regions controlling heading date have not been completely identified. The objective of this study was to identify genomic regions controlling oat heading date in subtropical environments. A set of 412 oat genotypes, developed from 1974 to 2015, was assessed for heading date in contrasting environments and genotyped using genotyping-by-sequencing (GBS). Phenotypic and genotypic data were used in single and multi-environment association models. Quantitative trait loci (QTL) associated to heading date were identified on oat consensus groups Mrg02, Mrg05, Mrg06, Mrg12, and Mrg21. Some of the findings confirmed the association of genomic regions with heading date, while others emerge as new candidate regions associated to the trait. The genomic regions identified on Mrg02 and Mrg12 were associated to Vernalization 3 (Vrn3), while the genomic region identified on Mrg21 is associated with Vernalization 1 (Vrn1). The Vrn1 region was detected in Londrina, an environment with reduced vernalization condition, and in the multi-environment model. The results reveal that some genotypes of the panel are responsive to vernalization, increasing the days to heading without this environmental stimulus. Our results provide important contribution for a better understanding of heading date in subtropical environments and a strong basis for marker-assisted selection in oats.
Assuntos
Avena/genética , Flores , Locos de Características Quantitativas , Genoma de Planta/genéticaResumo
Castor bean (Ricinus communis L.) is an oleaginous plant with annual cycle and occasionally biennial cycle in tropical areas, with mean cycle of 150 days for the majority of annual cultivars and 120 to 130 days for annual early cultivars. The objective of this study was to evaluate the agronomic characteristics of castor cultivars according to environmental crop and sowing season. The experiment was conduced at Embrapa Clima Temperado - Pelotas/RS, in two places. The castor cultivars used in this research were 'Al Guarany 2002', 'IAC 80', 'IAC 226' and 'BRS 188 Paraguaçu', which were sown in two sowing times: the first was in early November (between 1st and 5st) and the second was in early December (between 1st and 5st). Each sowing season was constituted of 12 experimental units, distributed in three random blocks. It was evaluated the emergency, plant height and first spike insertion , flowering and harvest time, pest and disease attacks. The WinStat program Version 2.0 was used for data statistical analysis. There was a significant difference among cultivar behaviors between the environmental crops and sowing seasons. The second sowing season provided a larger plant and first spike insertion was higher. It also promoted retardation in the flowering and harvesting time. The differences among cultivars, between the two environmental crops, were clearer in the pest and disease attacks, but also in morphologic characteristics of castor plant.
A mamona (Ricinus communis L.) é uma planta oleaginosa anual e, ocasionalmente, bienal em regiões tropicais, com ciclo médio de 150 dias para a maioria das cultivares anuais e de 120 a 130 dias para cultivares anuais precoces. O objetivo deste trabalho foi avaliar características agronômicas de cultivares das mamonas 'Al Guarany 2002', 'IAC 80', 'IAC 226' e 'BRS 188 Paraguaçu'em função do ambiente de cultivo e da época de semeadura. As cultivares foram semeadas entre o primeiro e o quinto dia dos meses de novembro e dezembro, na Embrapa Clima Temperado, em Pelotas, Rio Grande do Sul. Cada época teve 12 unidades experimentais em três blocos casualizados. A emergência, a altura de planta e de inserção do primeiro cacho, o período de florescimento e colheita e o ataque de pragas e doenças foram avaliados e analisados com o programa WinStat Versão 2.0. O comportamento entre as cultivares diferiu entre locais de cultivo e época de semeadura. A inserção do cacho foi mais alta, e as florações e colheitas foram mais tardias em plantas da segunda época de semeadura. Danos por pragas e doenças e os descritores morfológicos da planta de mamona apresentaram diferenças entre os locais de cultivo.
Resumo
Castor bean (Ricinus communis L.) is an oleaginous plant with annual cycle and occasionally biennial cycle in tropical areas, with mean cycle of 150 days for the majority of annual cultivars and 120 to 130 days for annual early cultivars. The objective of this study was to evaluate the agronomic characteristics of castor cultivars according to environmental crop and sowing season. The experiment was conduced at Embrapa Clima Temperado - Pelotas/RS, in two places. The castor cultivars used in this research were 'Al Guarany 2002', 'IAC 80', 'IAC 226' and 'BRS 188 Paraguaçu', which were sown in two sowing times: the first was in early November (between 1st and 5st) and the second was in early December (between 1st and 5st). Each sowing season was constituted of 12 experimental units, distributed in three random blocks. It was evaluated the emergency, plant height and first spike insertion , flowering and harvest time, pest and disease attacks. The WinStat program Version 2.0 was used for data statistical analysis. There was a significant difference among cultivar behaviors between the environmental crops and sowing seasons. The second sowing season provided a larger plant and first spike insertion was higher. It also promoted retardation in the flowering and harvesting time. The differences among cultivars, between the two environmental crops, were clearer in the pest and disease attacks, but also in morphologic characteristics of castor plant.
A mamona (Ricinus communis L.) é uma planta oleaginosa anual e, ocasionalmente, bienal em regiões tropicais, com ciclo médio de 150 dias para a maioria das cultivares anuais e de 120 a 130 dias para cultivares anuais precoces. O objetivo deste trabalho foi avaliar características agronômicas de cultivares das mamonas 'Al Guarany 2002', 'IAC 80', 'IAC 226' e 'BRS 188 Paraguaçu'em função do ambiente de cultivo e da época de semeadura. As cultivares foram semeadas entre o primeiro e o quinto dia dos meses de novembro e dezembro, na Embrapa Clima Temperado, em Pelotas, Rio Grande do Sul. Cada época teve 12 unidades experimentais em três blocos casualizados. A emergência, a altura de planta e de inserção do primeiro cacho, o período de florescimento e colheita e o ataque de pragas e doenças foram avaliados e analisados com o programa WinStat Versão 2.0. O comportamento entre as cultivares diferiu entre locais de cultivo e época de semeadura. A inserção do cacho foi mais alta, e as florações e colheitas foram mais tardias em plantas da segunda época de semeadura. Danos por pragas e doenças e os descritores morfológicos da planta de mamona apresentaram diferenças entre os locais de cultivo.