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Tan spot, caused byPyrenophora tritici-repentis, is a serious foliar disease of wheat in Kazakhstan with reported yield losses as high as 50% during epidemic years. Here, we report the evaluation of a collection of 191 hexaploid spring and winter wheat lines for tan spot resistance and its underlying genetic architecture using genome-wide association study (GWAS). Our wheat collection comprised candidate varieties from Kazakhstan, Russia, and CIMMYT. It was genotyped using the DArTseq technology and phenotyped for resistance to tan spot at seedling and adult plant stages in Kazakhstan. DArTseq SNPs revealed high genetic diversity (average polymorphic information content = 0.33) in the panel and genome-wide linkage disequilibrium decay at 22 Mb (thresholdr2= 0.1). Principal component analysis revealed a clear separation of Eurasian germplasm from CIMMYT and IWWIP lines. GWAS identified 34 marker-trait associations (MTA) for resistance to tan spot and the amount of phenotypic variation explained by these MTA ranged from 4% to 13.7%. Our results suggest the existence of novel valuable resistant alleles on chromosomes 3BS, and 5DL and 6AL for resistance to Race 1 and Race 5, respectively, in addition to known genestsn1andtsc2.On chromosome 6AL, a genomic region spanning 3 Mb was identified conferring resistance to both Race 1 and Race 5. Epistatic interaction of associated loci was revealed on chromosomes 1B, 5B, 7B, 5A, and 6A contributing to additional variation of 3.2–11.7%. Twenty-five lines with the best allele combinations of SNPs associated with resistance to both races have been identified as candidates for future variety release and breeding. The results of the present study will be further validated in other independent genetic backgrounds to be able to use markers in breeding.

Hepatoprotective and antioxidative efficacy of garlic was investigated against cadmium induced toxicity in young and old rats. Animals were co-administered with 250 μl/kg garlic through gastric intubation for consecutive four days and 5 mg/kg cadmium chloride intraperitoneally (ones in last day of garlic administration). The results demonstrate that cadmium induced toxicity was less pronounced in old animals. Unchanged levels of membrane-bound cytochrome P-450 and lipid hydroperoxides were observed. Co-administration of garlic in old rats provided essential protection against cadmium toxicity. Significant depletion of the cadmium-dependent carbonyl proteins level and restored activity of antioxidant enzymes was also observed. In young rats, concomitant administration of garlic leads to less pronounced hepatoprotective effect compared to that in old rats as evident by higher levels of carbonyl proteins and incomplete recovery of cytochrome P-450 and antioxidant enzymes. On the other hand, in young rats elevated levels of non-enzymatic antioxidants were also observed. It can be concluded from the present results that cadmium toxicity is mediated through oxidative stress which can significantly restored by coadministration of garlic. We also suggest that in young rats the protective effect of garlic is associated with maintaining an adequate level of non-enzymatic antioxidant defense system, whereas in old rats these effects are associated with activation of the enzymatic antioxidant defense system. © 2012 GESDAV