engleski

Construction of an integrated linkage map in Vicia faba and comparative mapping with Medicago truncatula and other legume species

The main aim of our group has been to take advantage of the availability of trisomic stocks for 5 of the six chromosomes of faba bean to generate a composite genetic map of linkage groups localized to their respective chromosomes. Morphological traits, isozymes, RAPDs, seed protein genes and microsatellites were used to develop the only integrated map of the species. Eleven F2 populations with a total of 654 individuals sharing a common female parent were analyzed simultaneously. Linkage analysis revealed 15 major linkage groups, 7 of which were located on specific chromosomes. The composite map includes approximately 200 loci, covers 1670 cM and has allowed the detection of QTLs for important agronomic traits as seed weight or broomrape and Ascochyta fabae resistance as well as to tag a gene controlling resistance to Uromyces fabae. Since relatively few orthologous polymorphic markers have been placed on the faba bean map (isozymes and STSs from pea), we are transforming a set of RAPD markers into SCARs to correlate linkage maps across different legumes. In addition to this, 75 M. truncatula PCR-based primer pairs are being tested on genomic DNA from our faba bean mapping parents. Out of the 44 primer pairs that amplified genomic DNA, 14 were directly polymorphic and 8 required restriction enzyme digestion. A parallel analysis is being conducted in our chickpea and pea parental lines. Our goal is to sequence the corresponding amplification products to identify the mapable polymorphism prior to initiate the comparative mapping between these legume species.

Vicia faba; Medicago truncatula; linkage map; comparative mapping

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