As the main optical isomer of metalaxyl, metalaxyl-M has been widely used worldwide in recent years because of its notable effect on the prevention and control of crop diseases. Together with the toxicity and degradation of metalaxyl-M, the chemical has attracted the attention of researchers. The present study examined the toxic effects of metalaxyl-M on earthworms at 0 mg kg(-1) , 0.1 mg kg(-1) , 1 mg kg(-1) , and 3 mg kg(-1) on days 7, 14, 21 and 28 after exposure. The results showed that metalaxyl-M could cause an obvious increase in the production of reactive oxygen species (ROS) when the concentration was higher than 0.1 mg kg(-1) , which led to lipid peroxidation in earthworms. Metalaxyl-M can induce DNA damage in earthworms, and the level of DNA damage markedly increased with increasing the concentration of metalaxyl-M. Metalaxyl-M also has a serious influence on the activities of antioxidant enzymes, which results in irreversible oxidative damage in cells. The changes of these indicators all indicated that metalaxyl-M may cause cytotoxic and genotoxic effects on earthworms.

No abstract

Background: As a globally known staple food, rice is well domesticated in the world. Various regions have different food preferences, which lead to design the goals for breeding programs. Glutinous rice as a special endosperm type is also consumed as a staple food in East Asian countries by consumers’ preference. Genetic studies on glutinous rice could be conducive to improve rice quality and understand its development and evolution. Genome-wide association study was performed to explore the associated loci/genes underlying glutinous rice by using 2108 rice accessions. Results: A total of 399, 262 and 156 annotated genes with significant loci were identified to be associated with endosperm type. By combining the expression patterns analysis, 127, 81, and 48 candidate genes were screened in whole rice panel, indica, and japonica sub-populations with moderate expression in seeds. There were 32 genes, including three starch synthesis-related genes Wx, SSG6, and OsSSIIa, detected simultaneously in the whole rice panel and subpopulations, playing important role in determining glutinous rice. The main waxy haplotypes of three starch synthesis-related genes were identified by haplotype analysis, while the combined haplotype analyses, revealed that the waxy combined haplotype mainly distributed in Southeast Asia (SEA), SEA islands (SER) and East Asia islands (EAR). Through population structure and genetic differentiation, we proposed the evolutionary model of waxy haplotypes of the three genes from wild rice to japonica, and then to indica.Conclusion: It was concluded that the waxy haplotypes of the three genes firstly generated (or were directly inherited from wild rice) in japonica, and then flowed into indica in SER, SEA and EAR. These results provide valuable information for further gene discovery and understanding the development and evolution for glutinous rice.

Background: Wheat processing quality is an important factor in evaluating overall wheat quality, and dough characteristics are important when assessing the processing quality of wheat. As a notable germplasm resource, semi-wild wheat has a key role in the study of wheat processing quality.Results: In this study, four dough rheological characteristics were collected in four environments using a nested association mapping (NAM) population consisting of semi-wild and domesticated wheat varieties to identify quantitative trait loci (QTL) for wheat processing quality. A total of 49 QTL for wheat processing quality were detected, explaining 0.36–10.82% of the phenotypic variation. These QTL were located on all wheat chromosomes except for 2D, 3A, 3D, 6B, 6D and 7D. Compared to previous studies, 29 QTL were newly identified. Four novel QTL, QMlPH-1B.4, QMlPH-3B.4, QWdEm-1B.2 and QWdEm-3B.2, were stably identified in three or more environments, among which QMlPH-3B.4 was a major QTL. Moreover, eight important genetic regions for wheat processing quality were identified on chromosomes 1B, 3B and 4D, which showed pleiotropy for dough characteristics. In addition, out of 49 QTL, 15 favorable alleles came from three semi-wild parents, suggesting that the QTL alleles provided by the semi-wild parent were not utilized in domesticated varieties.Conclusions: The results show that semi-wild wheat varieties can enrich the existing wheat gene pool and provide broader variation resources for wheat genetic research.

Background: Wheat processing quality is an important factor in evaluating overall wheat quality and dough characteristics are important in assessing the processing quality of wheat. As an important germplasm resource, semi-wild wheat plays an important role in the study of wheat processing quality.Results: In this study, four dough rheological characteristics were therefore collected in four environments using a nested association mapping (NAM) population, consisting of semi-wild and domesticated wheat varieties, which was used to identify quantitative trait loci (QTL) for wheat processing quality. A total of 49 QTL for wheat processing quality were detected, explaining 0.36–10.82% of the phenotypic variation. These QTL were located on all wheat chromosomes except for 2D, 3A, 3D, 6B, 6D and 7D. Compared to previous studies, 29 QTL were newly identified. Four novel QTL, QMlPH-1B.4, QMlPH-3B.4, QWdEm-1B.2 and QWdEm-3B.2, were stably identified in three or more environments, of which QMlPH-3B.4 was a major QTL. Moreover, eight important genetic regions for wheat processing quality were identified on chromosomes 1B, 3B and 4D, which showed pleiotropy for dough characters. In addition, out of 49 QTL, 15 favorable alleles came from three semi-wild parents, suggesting that the QTL alleles provided by the semi-wild parent were unutilized in domesticated varieties.Conclusions: The results show that the semi-wild wheat varieties can enrich the existing wheat gene pool and provide broader variation resources for wheat genetic research.