Fusarium head blight (FHB) of wheat has become a serious threat to wheat crops in numerous countries. In addition to loss of yield and quality, this disease is of primary importance because of the contamination of grain with mycotoxins such as deoxynivalenol (DON). The Swiss winter cultivar Arina possesses significant resistance to FHB. The objective of this study was to map quantitative trait loci (QTL) for resistance to FHB, DON accumulation and associated traits in grain in a double haploid (DH) population from a cross between Arina and the FHB susceptible UK variety Riband. FHB resistance was assessed in five trials across different years and locations. Ten QTL for resistance to FHB or associated traits were detected across the trials, with QTL derived from both parents. Very few of the QTL detected in this study were coincident with those reported by authors of two other studies of FHB resistance in Arina. It is concluded that the FHB resistance of Arina, like that of the other European winter wheat varieties studied to date, is conferred by several genes of moderate effect making it difficult to exploit in marker-assisted selection breeding programmes. The most significant and stable QTL for FHB resistance was on chromosome 4D and co-localised with the Rht-D1 locus for height. This association appears to be due to linkage of deleterious genes to the Rht-D1b (Rht2) semi-dwarfing allele rather than differences in height per se. This association may compromise efforts to enhance FHB resistance in breeding programmes using germplasm containing this allele.
Fusarium head blight (FHB), mainly caused by Fusarium graminearum and F. culmorum, can significantly reduce the grain quality of wheat (Triticum aestivum L.) due to mycotoxin contamination. The objective of this study was to identify quantitative trait loci (QTLs) for FHB resistance in a winter wheat population developed by crossing the resistant German cultivar Dream with the susceptible British cultivar Lynx. A total of 145 recombinant inbred lines (RILs) were evaluated following spray inoculation with a F. culmorum suspension in field trials in 2002 in four environments across Germany. Based on amplified fragment length polymorphism and simple sequence repeat marker data, a 1,734 cM linkage map was established assuming that the majority of the polymorphic parts of the genome were covered. The area under disease progress curve (AUDPC) was calculated based on the visually scored FHB symptoms. The population segregated quantitatively for FHB severity. Composite interval mapping analysis for means across the environments identified four FHB resistance QTLs on chromosomes 6AL, 1B, 2BL and 7BS. Individually the QTLs explained 19%, 12%, 11% and 21% of the phenotypic variance, respectively, and together accounted for 41%. The QTL alleles conferring resistance on 6AL, 2BL and 7BS originated from cv. Dream. The resistance QTL on chromosome 6AL partly overlapped with a QTL for plant height. The FHB resistance QTL on 7BS coincided with a QTL for heading date, but the additive effect on heading date was of minor importance. The resistance QTL on chromosome 1B was associated with the T1BL.1RS wheat-rye translocation of Lynx.
Glycerophosphorylcholine, inositol, and sorbitol were measured in rat kidney homogenates and tubules from inner medulla and papilla by enzymatic spectrophotometric techniques. Organic osmolytes exhibited their highest concentrations in the papillary tip. In contrast to glycerophosphorylcholine and sorbitol, inositol was of similar high concentrations in inner and outer medulla. Freshly prepared inner medullary tubules maintained tissue osmolyte concentrations under control, antidiuretic, and furosemide diuretic conditions. When tubules were incubated in vitro over 90 min, tubular organic osmolyte concentrations decreased as a function of extracellular NaCl, but not urea concentrations. Organic osmolyte disappearance from cells was quantitatively recovered from the medium. In contrast, medium lactate dehydrogenase activity did not rise in parallel and tubular ATP remained constant. Glucose up to a concentration of 200 mM increased tubule and medium sorbitol. The results obtained indicate that glycerophosphorylcholine, sorbitol, and inositol rapidly adapt their intracellular concentrations to extracellular NaCl osmolality by a change in tubular plasma membrane permeability. In addition sorbitol levels are regulated by the extracellular glucose concentration.
The effect of acute changes in extracellular tonicity on cell electrolyte concentrations at the renal papillary tip and on organic osmolytes in different kidney zones was studied using electron microprobe analysis and high-performance liquid chromatography in four groups of rats: controls, 1- or 4-h water diuresis, and 4-h water diuresis followed by 30-min deamino-[Cys1,D-Arg8]vasopressin (ddAVP). The sum of the papillary interstitial concentrations of Na, K, and Cl was reduced from 981 mmol/kg wet wt in controls to 318 mmol/kg wet wt after 4-h diuresis and increased after ddAVP to 840 mmol/kg wet wt. In papillary collecting ducts intracellular electrolytes fell from 225 to 156 mmol/kg wet wt after 4-h diuresis and rose to 268 mmol/kg wet wt (significantly higher than control) after ddAVP. Organic osmolytes [sum of glycerophosphorylcholine (GPC), betaine, myo-inositol, and sorbitol] at the papillary tip decreased from 2,018 (control) to 1,037 mmol/kg protein after 4-h diuresis and did not increase after ddAVP. After ddAVP, cell P concentration, an index of cell GPC concentration, increased, indicating cell shrinkage. GPC concentration increased, indicating cell shrinkage. The results suggest that the concentrations of all osmoeffectors in papillary cells initially increase due to cell shrinkage in response to hypertonic stress. The higher intracellular ionic strength may be a signal for modulation of transport and metabolism of organic osmolytes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.