IDENTIFICAÇÃO DE CLONES BAC COM MARCADORES MOLECULARES VISANDO A INTEGRAÇÃO DE MAPAS FÍSICOS E GENÉTICOS

BAC libraries have been extensively used in physical mapping, positional cloning and comparative studies of genomes evolution. With the aim to physical map genomic regions of Coffea arabica, we started the identification and characterization of BAC clones from a C. arabica hybrid timor 832/2 library. The library contains 56.832 BAC clones with average size of 120 Kb, representing 5.5 times the genome. For BAC identification, pooling of the clones was performed for each 384 well plate. After DNA extraction, the pools were grouped to form 15 super-pools of BAC-DNA, each clone representing approximately 5760 clones. For the identification of BAC of interest PCR screening in pools and superpools was performed, followed by colony filters hybridization containing 384 clones. To selection of plates pools and superpools, primers based on AFLPs linked to rust resistance locus (M-8, SAT-244 and BA-124) were used. We also used the markers: SSR-18 (GL1), SSR-16 (GL2), ACGG-1 (GL3), CCG-3 (GL6), from four linkage groups of partial genetic map of C. arabica to identify BACs and position for each ligation group. The selected BACs were confirmed by hybridization through the extraction of individual clones followed by PCR to check the marker of interest. So far were identified 32 BAC clones for resistance to rust markers and 98 for the four linkage groups. The selected BACs are going to be sequenced to perform physical mapping of the region containing the locus of resistance to rust.