Mapping of QTLs for common bean traits using microsatelites markers / Mapeamento de QTLs para caracteres do feijoeiro por meio de microssatÃlites

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The identification of QTLs is the initial step in the application of the selection assisted by molecular markers in breeding programs. The common bean counts on molecular map with good saturation, QTLs identified and SSR markers. However until the moment, there is few QTLs linked to SSR markers, therefore the identification of these markers for the common bean is recent. The objective of this work was to evaluate, in diverse environments of Minas Gerais State, segregating families derived from the cross of Jalo EEP 558 and Small White lines, by 100-seed weight, plant architecture, grain yield, reaction of angular leaf spot and oidium, and estimate genetic parameters, mapping and identifying QTLs for these characters using SSR markers. It was possible to infer that the segregating families presented significant differences for all characters, and the genitors were highly divergent for 100-seed weight and angular leaf spot reaction. High heritability estimates were obtained for 100-seed weight and angular leaf spot reaction. The effect of the environment influenced the expression of the characters, as well as of the genotype x environments interaction, except for the plant architecture. The decomposition of the genotype x environments interaction showed the predominance of the complex portion for all characters. In the case of 100-seed weight and the angular leaf spot reaction estimates of Pearson and Spearman correlations were of moderate values. Reaction to angular leaf spot showed negative correlation with 100-seed weight and positive correlation with plant architecture. Using LOD score of 3.90 and the Kosambi function a map with 400,01 cM counted on 24 markers placed on eight linkage groups with average length of 50.01 cM and 25,01 cM of average distance between markers. Using the methods of the multiple linear regression through the stepwise procedure and the mapping for composed interval, it was possible to associate SSR markers to QTLs for the averages of 100-seed weight, plant architecture, grain yield and angular leaf spot reaction. The QTLs more steady and associated to high proportion of genetic variance were detected for 100-seed weight and angular leaf spot reaction. The markers BM152 and BM210 are distinguished for had been associated to the QTLs for 100-seed weight, the X80051 marker was associated to the grain yield and the markers BM210 and BM146 were associated to angular leaf spot reaction.

ASSUNTO(S)

phaseolus vulgaris angular leaf spot ssr 100-seed weight, ssr tamanho do grÃo mancha angular phaseolus vulgaris melhoramento vegetal

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