RESUMO -O Banco Ativo de Germoplasma de Milho (BAGMilho) preservado na Embrapa Milho e Sorgo mantém cerca de 4.000 variedades. Entretanto, essas variedades não têm o padrão agronômico das cultivares comerciais, o que reduz o seu potencial do uso direto. O pré-melhoramento possibilita o desenvolvimento de genótipos com maior potencial de uso por meio da hibridização entre acessos do BAGMilho e genótipos melhorados. O objetivo deste trabalho foi avaliar famílias endogâmicas obtidas de cruzamentos entre linhagens-elite e os acessos do BAGMilho composto-fonte de resistência à mancha-branca e composto-fonte de resistência à ferrugem-polissora quanto à reação a patógenos, produtividade e caracteres agronômicos. Famílias endogâmicas derivadas de retrocruzamentos entre estes compostosfonte de resistência e linhagens-elite foram avaliadas em cruzamentos com testadores dos grupos heteróticos duro e dentado. Os ensaios foram conduzidos em Sete Lagoas e Nova Porteirinha em duas épocas de semeadura. Os resultados permitiram selecionar as famílias endogâmicas MB130, MB181, MB164, FP109, FP133, FP104, FP120, FP112, FP103 e FP140 para uso em cruzamentos com linhagens do grupo heterótico duro e as famílias endogâmicas MB024, MB032, MB083, FP028, FP036 e FP020 para uso em cruzamentos com linhagens do grupo heterótico dentado.Palavras-chave: recursos genéticos, fitopatologia, Zea mays, Pantoea ananatis, Puccinia polysora. MAIZE PRE-BREDING FOR RESISTANCE TO WHITE SPOT AND POLYSORA RUSTABSTRACT -The Maize Active Germplasm Bank (GBMaize) preserves about 4,000 varieties of maize. However, these varieties do not have the standard commercial performance that reduces their potential of agricultural use. Pre -breeding enables the development of greater agricultural use of genotypes by hybridization between the accessions from GBMaize and improved genotypes. The aim of this study was to evaluate inbred families obtained from crosses between inbred lines and accessions of GBMaize called source of resistance to white spot composite and source of resistance to polysora rust composite in crosses for resistance to pathogens, grain yield and agronomic traits. Inbred families derived from crosses between inbred lines and source of resistance to white spot and source of resistance to polysora rust composites were evaluated in crosses with flint and dent heterotic patterns testers. The trials were conducted in Sete Lagoas and Nova Porteirinha in two sowing dates for the evaluation of resistance to pathogens, yield and traits of agronomic importance. The results allowed select inbred families MB130, MB181, MB164, FP109, FP133, FP104, FP120, FP112, FP103 and FP140 for use in crosses with flint heterotic pattern and inbred families MB024, MB032, MB083, FP028, FP036 and FP020 for use in crosses with dent heterotic pattern.
Culturing of sweet sorghum is being considered as an excellent option for ethanol production, from an agronomical and industrial point of view. At present, information regarding the best soil water tension for beginning sweet sorghum irrigation is not available; hence, this study aimed to determine the adequate soil water tension under field conditions for beginning irrigation of four cultivars of sorghum. Two experiments were conducted at Nova Porteirinha, MG, in a randomized block design with subsubdivided plots having four replications. Each experiment comprised six treatments of soil water tension (plots)-20, 40, 60, 80, 100, and 120 kPa-for resuming sweet sorghum irrigation, and four sweet sorghum cultivars (subplots)-BRS 508, BRS 509, BRS 511, and CMSXS647. After planting, the soil water level in the plots was elevated to field capacity (10 kPa), and then the treatments were applied. During treatment application, irrigation was resumed when the soil water tension reached the limit established in order to elevate the soil water tension to 10 kPa. The amount of water replaced during each irrigation was determined by generating a soil water retention curve for the experimental area. The following parameters were evaluated: green mass production, juice volume, soluble solids (Brix), and tons of Brix per hectare (TBH). The different soil water tensions and cultivars, agricultural year, and interaction between tension and year significantly affected (p ≤ 0.05) the characteristics evaluated, according to the F test. The agronomical characteristics of the evaluated cultivars showed linear relationship with water supply in the soil. According to TBH, irrigation of sweet sorghum needs to be performed when the soil tension reaches 20 kPa. The TBH values did not differ significantly among the four cultivars at the 5% significance level according to Tukey test. ResumoA cultura do sorgo sacarino vem sendo considerada uma ótima opção, sob os pontos de vista agronômico e industrial, para a produção de etanol. Como não há informações sobre a melhor tensão da água do solo para o início da irrigação do sorgo sacarino, objetivou-se determinar em campo a tensão de água do solo adequada para o início da irrigação de quatro cultivares. Foram conduzidos dois experimentos, em Nova Porteirinha, MG, no delineamento em blocos casualizados, no esquema de parcelas subsubdivididas, em quatro repetições. Cada um dos experimentos foi constituído por seis tratamentos de tensão da água do solo (parcelas); 20, 40, 60, 80, 100 e 120 kPa, para o reinício da irrigação do sorgo sacarino, e de quatro cultivares de sorgo sacarino (subparcelas): BRS 508, BRS 509, BRS 511 e CMSXS647. Após o plantio, as parcelas tiveram a umidade do solo elevada à capacidade de campo (10 kPa), quando a partir de então foram aplicados os tratamentos. Durante o período de aplicação dos tratamentos, sempre que a tensão de água no solo atingia o limite de tensão estabelecido, o sistema de irrigação do tratamento era acionado, funcionando o tempo necessário para ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.