Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: DNA polymorphisms and haplotype patterns of transcription factors involved in barley endosperm development are associated with key agronomic traits | Haseneyer et al. BMC Plant Biology 2010 10 5 http 1471-2229 10 5 BMC Plant Biology RESEARCH ARTICLE Open Access DNA polymorphisms and haplotype patterns of transcription factors involved in barley endosperm development are associated with key agronomic traits Grit Haseneyer1 4 5 Silke Stracke1 6 Hans-Peter Piepho2 Sascha Sauer3 Hartwig H Geiger4 Andreas Graner 1 Abstract Background Association mapping is receiving considerable attention in plant genetics for its potential to fine map quantitative trait loci QTL validate candidate genes and identify alleles of interest. In the present study association mapping in barley Hordeum vulgare L. is investigated by associating DNA polymorphisms with variation in grain quality traits plant height and flowering time to gain further understanding of gene functions involved in the control of these traits. We focused on the four loci BLZ1 BLZ2 BPBF and HvGAMYB that play a role in the regulation of B-hordein expression the major fraction of the barley storage protein. The association was tested in a collection of 224 spring barley accessions using a two-stage mixed model approach. Results Within the sequenced fragments of four candidate genes we observed different levels of nucleotide diversity. The effect of selection on the candidate genes was tested by Tajima s D which revealed significant values for BLZ1 BLZ2 and BPBF in the subset of two-rowed barleys. Pair-wise LD estimates between the detected SNPs within each candidate gene revealed different intra-genic linkage patterns. On the basis of a more extensive examination of genomic regions surrounding the four candidate genes we found a sharp decrease of LD r2 within 1 cM in all but one flanking regions. Significant marker-trait associations between SNP sites within BLZ1 and flowering time BPBF and crude protein content and BPBF and starch content were detected. Most haplotypes occurred at frequencies and therefore were rejected from the .
