| 1. |
- Andersson, Annhild, et al.
(författare)
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Occurrence of aphid vector and genetic tolerance to infection by potyvirus in hot pepper
- 2010
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Ingår i: Euphytica. - : Springer Science and Business Media LLC. - 0014-2336 .- 1573-5060. ; 172, s. 77-91
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Tidskriftsartikel (refereegranskat)abstract
- The productivity and marketable quality of hot pepper (Capsicum annuum var. annuum L.) are low in tropical regions mainly due to virus infections and lack of effective virus management strategies. The absence of effective virus management strategies could be attributed to lack of information on virus vectors and host resistance. Parental (P(1) and P(2)) and progeny (F(1), B(1), B(2) and F(2)) generations of five hot pepper crosses were grown in Ethiopia at three sites (Bako, Hawasa and Melkasa) to monitor number and species of potential aphid vectors, disease incidence levels with regards to natural infections by Potato virus Y (PVY) and Ethiopian pepper mottle virus (EPMV) complex, and to determine genetic tolerance of the crop to the viruses. Disease incidence was assessed before the flowering stage of the crop plants using visible disease symptoms due to infections by PVY and EPMV. The serological tests revealed presence of symptomless genotypes of the crop to the virus infections. Aphid species potentially transmitting the viruses, such as Acyrthosiphon pisum (Harris), Aphis fabae (Scopoli), and Myzus persicae (Sulzer), were identified from specimens caught by yellow water traps. The highest number of aphids from yellow water traps was recorded at a dense foliage growth stage of the crop at Melkasa. Highly significant variation was observed among generations of the five crosses in response to infections by PVY and EPMV complex. The most susceptible parents had the levels of disease incidences ranging from 80 to 90%, whereas their progenies had only below 30% incidence levels. The most tolerant parent remained symptomless to the natural infections of PVY- and EPMV-complex. Incidence levels in progenies of a cross from the most susceptible and tolerant parents remained below 20%. Based on serological test, the proportion of PVY-positive plants ranged from 0 to 75% and of EPMV-positive plants from 0 to 25%, with 0 to 17% co-infection by the two viruses. Availability of virus sources in the vicinity, efficiency of aphids in vectoring, weather conditions during the growth period, genetic tolerance and the growth stage of the crop affected natural infection by PVY- and EPMV-complex. Exploitation of the genetic potential of introduced elite genotypes and their progenies along with breeding elite local cultivars for resistance and excluding aphid vectors at young (seedling) stage of the crop plants could be helpful for minimizing losses in yield and quality of hot pepper due to infections by PVY- and EPMV-complex.
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| 2. |
- Olausson, Eva A, et al.
(författare)
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Small particle size of a solid meal increases gastric emptying and late postprandial glycaemic response in diabetic subjects with gastroparesis.
- 2008
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Ingår i: Diabetes research and clinical practice. - : Elsevier BV. - 1872-8227 .- 0168-8227. ; 80:2, s. 231-7
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Tidskriftsartikel (refereegranskat)abstract
- Our goal was to investigate if food of small particle size increases the gastric emptying rate and lessens the fall in postprandial blood glucose in seven subjects with Type 1 diabetes and gastroparesis. Two solid meals of identical composition but of different particle size, with 5MBq (99m)Tc added to the meals, were ingested in randomized order in seven subjects with Type 1 Diabetes Mellitus and gastroparesis and seven healthy subjects. During 180min blood glucose and insulin concentrations were measured and gastric emptying of the ingested meals was registered by a gamma camera. The lag phase in the stomach was significantly shorter, the radioactivity remaining in the stomach after 120min (T(120)) was significant less and the postprandial blood glucose dip was less and of shorter duration after a small particle (SP) meal, compared to a large particle (LP) meal in diabetic subjects. Gastric emptying did not differ significantly between groups after an SP meal. Food of small particle size increases the gastric emptying rate and reduces the postprandial blood glucose dip in both magnitude and duration in Type 1 diabetic subjects with gastroparesis, which is likely to be of importance in achieving good metabolic control.
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| 3. |
- Viketoft, Maria, et al.
(författare)
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Cultivar Effects on the Interaction between Free-Living Plant-Parasitic Nematodes and the Fungal Pathogen Rhizoctonia solani in Potato
- 2017
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Ingår i: American Journal of Potato Research. - : Springer Science and Business Media LLC. - 1099-209X .- 1874-9380. ; 94, s. 314-322
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Tidskriftsartikel (refereegranskat)abstract
- Crop damage is associated with infection by plant pathogens but can also arise through abiotic factors. However, the plant pathogens are involved in biotic interactions with other plant pathogens, and these interactions may differ depending of the cultivar of the crop. Here, the interaction between the fungus Rhizoctonia solani (AG3) and free-living plant-parasitic nematodes was investigated in a pot experiment with different potato cultivars. No synergistic interaction between R. solani and plant-parasitic nematodes was found, instead there was an effect of treatment with lower tuber yield when nematodes occurred alone. There were differences among the cultivars regarding incidence of black scurf, dry weight of stems and tubers, and there was interactive effects between treatment and cultivar regarding dry weight of stolons and roots. Therefore, results concerning incidence and damage of R. solani and/or plant-parasitic nematodes found for one cultivar may not be applicable to other cultivars.
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