839 research outputs found
Efeito dos inseticidas nas plantas.
Revisão de literatura sobre os efeitos de inseticidas nas plantas.bitstream/item/134093/1/45251-1.pd
Behavior of sorghum lines in relation to sugarcane borer Diatraea sacchardis (Fabricius, 1974).
Sorghum lines were evaluated for resistance to the sugarcane borer (Diatraea saccharalist) at the Afranio Research Field, Pernambuco in 1976. The infestations of the lines are given in Table 1. There was significant simple positive correlation between infestation percentage and infestation intensity (r= 0.86*). There was no correlation between infestation percentage and infestation intensity with plant height or with number and external diameter of internodes.E em Annual Plant Resistance Insects Newsletter, v.4, p.38-39, 1978
Selection strategies of segregant soybean populations for resistance to Asian rust.
The objective of this work was to identify the best selection strategies for the more promising parental combinations to obtain lines with good resistance to soybean Asian rust (Phakopsora pachyrhizi). Two experiments were carried out in the field during the 2006/2007 and 2007/2008 growing seasons, to determine the percentage of infected leaf area of individual plants offive parents and their segregant F2 and F3 populations. The data obtained indicates that additive genetic variance predominates in the control of soybean resistance to Asian rust, and that the year and time of assessment do not significantly inftuence the estimates of the genetic parameters obtained. The narrow-sense heritability (h~ ranged from 23.12 to 55.83%, and indicates the possibility of successful selection of resistant individuais in the early generations of the breeding programo Ali the procedures used to select the most promising populations to generate superior inbred lines for resistance to P pachyrhizi presented similar results and identified the BRO1-18437 x BRS 232 population as the best for inbred line selection
Interference of genotypes x environments interaction in the genetic control of resistance to asian rust soybean.
Coeficiente de parentesco entre as principais cultivares de feijão do tipo carioca.
Foi obtida a genealogia das principais cultivares de feijão tipo carioca em uso no Brasil e estimado o grau de parentesco entre elas. Foi obtida a genealogia de 15 cultivares
Seleção precoce para tipo de grão e suas implicações no potencial produtivo de progênies de feijoeiro.
O objetivo deste trabalho foi avaliar o efeito da seleção precoce para tipo de grão na variabilidade e potencial produtivo de progênies de feijoeiro. Para isso foram avaliadas progênies do cruzamento entre as linhagens P-180 (grãos tipo carioca) x Paraná (grãos pardos)
Pollen mixture, a recombination alternative in common bean breeding.
Recombination can be a limiting factor in recurrent selection programs, especially in species such as common bean where artificial hybridization reduces seed setting. Therefore, the development of new techniques to improve recombination efficiency is important. Experiments were conduted in two sowing periods, July (autumn-winter season) and February (dry growing season), using the ESAL 686 and Small White cultivars as the female parents and the Carioca, Ouro Negro and ESAL 686 or Small While cutivars as male parents, depending ot the female parent. Five technicians with different hybridization experience and two hybridization methods (with and without emasculation) were tested. A mixture of pollen from the three male parents was used in the pollinations, which were made in greenhouse. The resulting F1 seeds were sown in the field and the male parent identified by morphological markers. The greatest pollination success (68%) occurred in the autumn-winter season without emasculation. It was also observed that the technicians differed in efficiency, but no method x technician interaction was detected. The pollen mixture was efficient to improve recombination
Progresso genético após oito ciclos de seleção recorrente para produtividade de grãos do feijoeiro.
O objetivo deste trabalho foi estimar o progresso genético após oito ciclos de seleção recorrente visando à obtenção de linhagens de feijão com alta produtividade
Maternal effect associated to cooking quality of common bean.
O tempo de cozimento dos grãos de feijão é um dos principais fatores envolvidos com a adoção de uma cultivar de feijão. Como o tegumento e os cotilédones estão em gerações diferentes quando da condução de populações segregantes, é indispensável identificar qual dessas estruturas afeta a cozimento e assim orientar os trabalhos de melhoramento. Foram avaliados os genitores, as gerações F1, F2, F3 e seus recíprocos dos cruzamentos: CI-107 x Carioca-80, CI-107 x Amarelinho e CI-107 x G2333 e seus respectivos recíprocos. Constatou-se efeito materno na expressão do caráter, isso porque o tegumento foi o principal constituinte do grão de feijão responsável pelo cozimento. As inferências obtidas por meio dos parâmetros genéticos e fenotípicos não sofreram alterações expressivas com o decorrer do armazenamento, embora o tempo de cozimento incrementasse com a idade dos grãos
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