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 natural e a decisão do melhorista sobre o melhor momento de abrir o 'bulk' na cultura do feijoeiro.

Foi realizado o presente trabalho para verificar se a postergação da abertura do ?bulk? pode ser vantajosa para os melhoristas de feijão

Desempenho de famílias de populações segregantes do feijoeiro de diferente número de intercruzamento de plantas F2.

Foi realizado o presente trabalho para verificar se o intercruzamento de plantas F2, altera as propriedades genéticas das populações segregantes e aumenta a probabilidade de obter linhagens superiores

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

Breeding potential of single, double and multiple crosses in common bean.

This common bean study was carried out to improve the understanding of the several strategies that can be used to obtain segregant populations in self-pollinating plant breeding programs. Eight inbred lines were crossed in a pyramidal form, and four single, two double and one multiple hybrid were obtained. The potential of the different hybrids was investigated based on the performance of the F2 and F2 plus F3 segregant populations. The potential for obtaining superior inbred lines was estimated by (m + a), wich in the average of the F inbred lines, and by the probability of a given population producing inbred lines that outperform the yield of the Pérola cultivar by 20%. It was shown that the use of multiple crosses is not advantageous when breeders have well defined objectives and experimental conditions to assess and identify te most promising segregant populations

Consequences of early selection for grain type in common bean breeding.

The common bean grain color is controlled by a large number of genes, probably distributed in all the chromosomes. Therefore, early selection for this trait is likely to cause an expressive reduction in the variability of other traits such as grain yield, which is the main objective of most breeding programs. This study was carried out to verify the effect of early (F2 generation) selection for grain type on grain yield in more advanced generations. The F2 population from the cross between the Ouro Negro (black grains) and Pérola (?carioca? - cream with brown stripes) type grains was used. The harvest seeds were divided into two groups, one with ?carioca? grains and another of mixed type, where no selection was applied. The F3 plants of both sub-populations were individually harvested resulting in 199 families per sub-populations. These 398 F3:4 families and the parent cultivars were assessed during the year 2000 dry season in Lavras and the F3:5 families in the winter of 2000 in Lavras and in Patos de Minas. On average, no yield differences among the non-selected and selected for grain type family means were detected. It was also observed that the heritability estimates were high and similar. It is, therefore, inferred that early (F2 generation) selection for grain type did not reduce the potential of the population for selection of superior inbred lines. Consequently, strong selection for grain color in the F2 generation, to screen out undesirable types will enable breeders to concentrate their efforts on the selection of other traits in the advanced generations. Only families with commercially acceptable grain type will be submitted to selection, increasing the chances of success

Avaliação do nível de infestação de Leucoptera coffeella (bicho mineiro) em cafeeiro sob manejo agroecológico em sistema solteiro e consorciado com bananeira.

bitstream/item/69066/1/022-silva-avaliacao.pdfPublicado também no Cadernos de Agroecologia, v. 7, n.2, 2012

'Talismã' - nova cultivar de feijoeiro pra Minas Gerais.

No Estado de Minas Gerais o melhoramento genético do feijoeiro vem sendo realizado em conjunto pela Universidade Federal de Lavras (UFLA), Universidade Federal de Viçosa (UFV), Empresa de Pesquisa Agropecuária de Minas Gerais (EPAMIG) e Empresa Brasileira de Pesquisa Agropecuária (Embrapa). Como fruto desse trabalho, foi desenvolvida a linhagem de feijão CII-102, que está sendo recomendada com o nome fantasia de BRSMG Talismã, sendo uma nova opção de cultivar de feijão com grãos tipo carioca para o estado