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Cultivated Chinese wheat germplasm has been a valuable genetic resource in international plant breeding. Patterns of gliadin among cultivated Chinese accessions are unknown, despite the proven value and potential novelty. The objective of this work was to analyse the diversity within improved Chinese wheat germplasm. The electrophoretic banding patterns of gliadin in winter wheat cultivars and advanced lines were determined by acid-polyacrylamide gel electrophoresis. For 148 leading commercial cultivars and promising advanced lines used in this study, 48 patterns were identified, 29 corresponding to ω-gliadin, nine to γ-gliadin, five to β-gliadin and five to α-gliadin. The most frequent patterns were A6 in ω; B in γ; B in β and A in the region of α. A total of 116 band types appeared in the 148 samples: 94 accessions had unique gliadin types, and 22 gliadin, types while not unique, were found in 54 accessions. The gliadin patterns of Chinese wheat cultivars and lines greatly differed from the patterns of wheat lines from other countries. Three patterns, E, J, H, M, N and O in the ω-zone had not been reported previously. Three wheat zones of China, the Northern Winter Wheat Region, the Yellow and Huai Valley River valleys Winter Wheat Region and the Southwestern Winter Wheat Region, showed different frequencies in their gliadin patterns. This information can be used to monitor genetic diversity with Chinese wheat germplasm. [ABSTRACT FROM AUTHOR]

In this study we investigated genetic polymorphisms of five metabolizing genes and their association with occupational chronic manganism. We recruited 49 patients with chronic manganism and 50 unrelated healthy control subjects who were welders and ferromanganese smelters and occupationally exposed to manganese dust and fume in the same workshops from three metallurgical industries. The controls were matched to the cases by sex, age, cigarette and alcohol intake, as well as the manganese exposure duration. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to genotype the cytochrome P450 2D6L gene (CYP2D6L) and the NAD(P)H:quinone oxidoreductase gene (NQO1). Allele-specific PCR was used to detect the cytochrome P450 1A1 gene (CYP1A1), and the glutathione-S-transferase mu and theta genes (GSTM and GSTT). The frequency of polymorphic alleles, a mutation of CYP2D6L, was significantly lower in patients with chronic manganism (16.3%) than in controls (29.0%). Individuals with the homozygote polymorphism (L/L) of CYP2D6 had a 90% decreased risk of chronic manganism compared with the wild-type (Wt/Wt) (odds ratio =0.10, 95% confidence interval = 0.01-0.82). A significant association between the CYP2D6 genotype subgroup and the latency of chronic manganese poisoning was also found. Patients who had homozygous (L/L) or heterozygous (Wt/L) mutant alleles developed manganism an average of 10 years later than those who were homozygous wildtype (Wt/Wt). However, the allele and genotype frequencies of CYP1A1 and NQO1 genes were distributed similarly in cases and controls. In addition, no difference in the frequencies of GSTM1 and GSTT1 null genotypes were observed between cases and controls. The results suggest that CYP2D6L gene polymorphism might influence susceptibility to manganese-induced neurotoxicity. However, because of limited sample size, our results should be validated in large-scale studies. [ABSTRACT FROM AUTHOR]

Lodging (LD) is a major constraint limiting the yield and forage quality of barley. Detailed analyses of LD component (LDC) traits were conducted using 246 F2 plants generated from a cross between cultivars ZQ320 and 1277. Genetic relationships between LD and LDC were evaluated by unconditional and conditional quantitative trait locus (QTL) mapping with 117 simple sequence repeat markers. Ultimately, 53 unconditional QTL related to LD were identified on seven barley chromosomes. Up to 15 QTL accounted for over 10% of the phenotypic variation, and up to 20 QTL for culm strength were detected. Six QTL with pleiotropic effects showing significant negative correlations with LD were found between markers Bmag353 and GBM1482 on chromosome 4H. These alleles and alleles of QTL for wall thickness, culm strength, plant height, and plant weight originated from ZQ320. Conditional mapping identified 96 additional QTL for LD. Conditional QTL analysis demonstrated that plant height, plant height center of gravity, and length of the sixth internode had the greatest contribution to LD, whereas culm strength and length of the fourth internode, and culm strength of the second internode were the key factors for LD-resistant. Therefore, lodging resistance in barley can be improved based on selection of alleles affecting culm strength, wall thickness, plant height, and plant weight. The conditional QTL mapping method can be used to evaluate possible genetic relationships between LD and LDC while efficiently and precisely determining counteracting QTL, which will help in understanding the genetic basis of LD in barley.