Pleiotropic effects of the sdw1 locus in barley populations representing different rounds of recombination|
Kuczyńska, Anetta; Mikołajczak, Krzysztof & Ćwiek, Hanna
Background: In the present study populations, representing different rounds of recombination were used for the
analysis of phenotypic effects associated with the sdw1/denso locus. Other studies have mostly focused only on
one type of population. Many different QTLs mapped at the same position as the sdw1/denso locus may
indicate a pleiotropy of this gene or a tight linkage between genes conditioning quantitative traits. To date,
results of studies have not unequivocally proven either of these two phenomena.
Results: Both breeding andmolecular mapping experimentswere undertaken to examine 200 single seed descent
(SSD) and 60 doubled haploid (DH) lines obtained fromthe Maresi (with a semi-dwarfing gene) and Pomo cross
combination. They were evaluated for the type of juvenile growth habit and certain agronomic traits were
measured after harvesting. The estimates of mean values, standard errors and significance of effects were
analyzed. In terms of the analyzed characteristics, the greatest variability was obtained for genotypes with the
prostrate growth habit. Microsatellite markers (SSR) were also used to identify co-segregation with the sdw1/denso locus and Bmag0013, Bmag0877, Bmag0306b markers were linked the closest. A partial linkage map of
chromosome 3H with the sdw1/denso semi-dwarfing gene was constructed and QTLs were identified.
Conclusions: Our experiments confirmed the impact of the semi-dwarfing gene on plant height, heading and
flowering date both in SSD and DH populations, which may indicate pleiotropy. Moreover, a partial linkage
between sdw1/denso locus and grain weight per spike and 1000-grain weight was found in the SSD population.
DH; Hordeum vulgare L; Quantitative traits; Semi-dwarfing gene; SSD; SSR markers