| Abstract Detail
Conference Wide Pinto, Fernanda de Oliveira [1], Maluf, Mirian Perez [2], Guerreiro-Filho, Oliveiro [3]. Analysis of EST-SSR markers in coffee progenies segregating to leaf-miner resistance. THE development of new coffee cultivars has been limited by the difficulty in early of selection desirable agronomic traits, since those characteristics exhibit complex genetic inheritance and significant environmental influence. Currently, molecular markers have been used as an alternative and efficient selection tool by breeding programs of several plant species. In coffee, some RAPD and AFLP markers were already identified and co-segregate with agronomic characteristics such as pathogen resistance. The main purpose of this work was to identify expressed microsatellite (SSR) markers associated with resistance to leaf-miner in coffee progenies These markers will be useful during selection for resistance to this insect by coffee breeding programs. The identification of potential SSR markers has been accomplished by directed search on the Brazilian Coffee ESTs Database. EST- SSR were preferentially selected from genes expressed in leaves and stressed tissues. Sequence analysis of 32 selected SSR loci showed that complex repeats (61%) are more frequent than tri- (21%) and di- (18%) nucleotide repeats. Also, expressed SSR are localized frequently in the 5’–UTR of the gene transcript. Moreover, most of the genes containing evaluated SSR are associated with defense mechanisms. Polimorphisms were analyzed in advanced progenies segregating for resistance to the leaf-miner. Genomic DNA extracted from 136 plants, all corresponding to advanced generations of a Coffea arabica X Coffea racemosa hybrid, were used for EST-SSR amplifications. Frequency of SSR alleles was 1.96/locus, and no polimorphism was identified among the genotypes evaluated. These results suggest that marker assisted-selection in coffee breeding should be performed on initial crosses and selection, where the genetic variability is still significant.
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1 - Agronomic Institute / IAC, Coffee Center \"Alcides Carvalho\", Av. Barão de Itapura, 1481, CP 28, Campinas, SP, 13001-970, Brazil
2 - Embrapa / IAC, Coffee Center \"Alcides Carvalho\", Av. Barão de Itapura, 1481, Guanabara, Campinas, SP, 13001-970, Brazil
3 - Instituto Agronomico, Centro de Café Alcides Carvalho, Av. Barao de Itapura, 1481, CP 28, Campinas, SP, 13012-970, Brazil
Keywords:
coffee
EST-SSR
leaf-miner.
Session: Poster-86
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:87 |
