Análisis conjunto de QTL de fecha de espigado en germoplasma de mejora constituido por pequeñas poblaciones interconectadas de haploides duplicados de cebada
2007
Cuesta Marcos, A.
The purpose of the present work is to validate the effect of the main loci determining heading date in a set of 285 doubled haploid barley lines, derived from 17 small interconnected populations, whose parents are cultivars commonly used in the Spanish barley breeding program, in which the group of the Aula Dei Experimental Station is involved. A set of markers, located on genomic regions related to heading date, were chosen according to the results obtained in the Beka x Mogador mapping population, developed in the Station and evaluated in similar environments as the lines of the present study. Besides, other heading date markers were included. The lines were evaluated in four field trials: two autumn and two winter sowings, and in one controlled greenhouse trial. A consensus linkage map was constructed with the 285 lines molecular data. Molecular data and marker positions were used to determine the genomic regions with significant effect on heading date in each trial. Markers allele effects in every significant region were estimated. The analyses revealed that, in most cases, there was a defined effect of one allele with respect to the others. Therefore, in most cases two alleles per QTL were detected, though polymorphism of flanking markers was notably higher. A comparison between PCR-based markers and RFLP markers in four regions containing major heading date genes was also carried out. The results revealed that there is a set of loci that accounts for an important percentage of the phenotypic variation, amenable for use in Marker Assisted Selection. Also, the role of the photoperiod response genes Ppd-H1 and Ppd-H2, the vernalization response genes Vrn-H1 and Vrn-H2, and the earliness per se locus Eam6, of which allele-specific of closely linked markers are available, was confirmed
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