Progresso genético em trinta anos de melhoramento do trigo em Minas Gerais

• Ano de defesa: 2007
• Autor(a) principal: Cargnin, Adeliano
• Orientador(a): Souza, Moacil Alves de
• Banca de defesa: Sediyama, Tocio , Fronza, Vanoli
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Triticum aestivum; Melhoramento; Avaliação de genótipos; Ganho genético
• Palavras-chave em Inglês: Triticum aestivum; Breeding; Genotypes evalution; Genetic gains
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/1376

Wheat cropping in the savannah region on Brazil-Central is a reality. In this region, the productivity of the wheat at higher altitude than 400m and under irrigation system is very superior to that on southern region, because the favorable climate conditions. In addition, there is a possibility for wheat upland crop in those savannah areas with altitude above 800m, where productivity around the national average is reached. Using both systems, there are great perspectives for increasing the national wheat production, as better cultivars provided with higher adaptation to the planting times are generated by research. The genetic improvement program should be periodically examined in order to identify possible problems during its phases and to maximize the activity planning by the breeders. The objective of this study was to quantify the genetic progress obtained by the wheat research programs under both upland and irrigated systems, over the period from 1976 to 2005, in Minas Gerais State. The efficiency of the wheat improvement programs under both systems were studied, by using the grain productivity data obtained in assays cropping and use values. The assays were conducted by the associated federal and state institutions for agricultural research. The irrigated and the upland systems were used in 19 places and 10 places, respectively, over the period from 1976 to 2005, in Minas Gerais State. The estimate of the environmental and genetic progresses were estimated by Vencovsky methodology. The average annual genetic progress estimated over the period from 1976 to 2005 was 48 kg ha-1 year-1 and 37 kg ha-1 year-1 in productivity average, under the upland and irrigated systems, respectively. Although the significant contribution of the genetic gains, the environmental improvements were important for increasing the productivity. The improvement programs of the upland and irrigated wheat promoted 33% and 35% renewal of genotypes along the years, respectively. Based on the results, it can be concluded that after 30 years undergoing research in Minas Gerais State, the genetic improvement of the upland and irrigated wheat led to positive and significant results that reflected on estimates of the average genetic gain in productivity. Those gains clearly indicated the wheat improvement programs in Minas Gerais State showed to be efficient, therefore contributing to the improvement of this crop.