Selection of Carioca type common beans lines with a pyramid of resistant alleles to anthracnose and other favourable phenotypes / SeleÃÃo de linhagens de feijÃo tipo carioca com pirÃmide de alelos de resistÃncia à antracnose e outros fenÃtipos favorÃveis

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

Resistant common bean cultivars is one of the best way to control the anthracnose, caused by Colletotricum lindemuthianum. Cultivars with a pyramid of two or more resistant alleles have priority for selection in breeding programs due to the short life of lines having only one resistant allele. Furthermore, in the selection of improved cultivars, superior agronomic phenotypes for other traits should also be considered. Among these traits resistance to angular leaf spot (Phaeoisariopsis griseola), plant architecture and grain type and yield are of most importance. The objectives of this research were to identify lines with a pyramid of resistant alleles to anthracnose and other desirable phenotypes for agronomical traits. Two hundred and fifty six lines from a backcross between the donor parent G2333, carrying three resistant alleles of independent genes (Co-42, Co-5 e Co-7) and the recurrent parents ESAL 696 and CI140, which have other superior agronomic phenotypes were evaluated. The lines were inoculated with three pathogen races (2047, 1545 and 73) and were analysed with two RAPD markers linked to the Co-5 allele. The lines were also evaluated for grain type and yield, resistance to angular leaf spot and plant architecture in four field trials. The genotypes of most lines were identified for anthracnose resistance, and the best five lines for grain yield, Carioca grain type, resistance to angular leaf spot and upright plant architecture were selected. Among the lines two have a pyramid with at least two resistant alleles of genes Co-5 and Co-7 and Co-42 and Co-5. These lines have a chance to become new cultivars. Other lines carrying only the Co-7 allele were identified, but they need to be studied further and the allele marked in order to be utilized.

ASSUNTO(S)

seleÃÃo breeding common bean colletotrichum lindemuthianum melhoramento vegetal melhoramento antracnose selection colletotrichum lindemuthianum feijÃo anthracnose

ACESSO AO ARTIGO

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