Home About us Contact
|
Home About us Contact | ||
|
|
||
Solanum Tuberosum L. (solanum + tuberosum_l)
Selected AbstractsPHYSICAL-CHEMICAL AND SENSORY QUALITY EVALUATION OF POTATO VARIETIES (SOLANUM TUBEROSUM L.)JOURNAL OF FOOD QUALITY, Issue 2 2000J.E. PARDO ABSTRACT Seven table potato varieties were studied for pH, soluble solids content, moisture, firmness, color, external appearance of raw tubers and flavor and texture of the fried and boiled product. Monalisa was the most appreciated variety regarding external appearance, Bartina was preferred for the flavor of the fried product while Victoria and Desiree were the best for flavor and texture of boiled potatoes. The different scores by variety depending on frying or boiling suggest a specific use for each variety. Soluble solids content, pH, and moisture determinations showed minimal differences between varieties. Firmness was highest in the two varieties with the least moisture (Desiree and Victoria) and lowest in varieties with a high degree of moisture (Bartina and Caesar); fresh potato firmness had a positive correlation with these sensorial parameters when the product was boiled. All colorimetric parameters were useful to discriminate red skin from yellow-white skin varieties. [source] Analysis of protein profiles of genetically modified potato tubers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2003M. Careri Traceability of genetically modified (GM) foods demands the development of appropriate reliable techniques in order to identify and quantify peptide or nucleic acid residues in GM plants and food products through the food chain. In this study the applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was demonstrated for the characterization of proteins of transformed and untransformed potato (Solanum Tuberosum L.) tubers. In GM tubers the expression level of the G1-1 gene, which regulates transition from dormancy to sprouting tubers, was inhibited by antisense technology. The analysis of antisense transformed lines showed that several of them exhibited a significant delay in sprouting relative to the control lines, in accordance with a decrease in the transcript level. Preliminary attempts to compare the protein patterns obtained from transformed and control lines using traditional electrophoresis were not able to reveal differences in the low-kDa range. Instead, MALDI-TOFMS applied to total peptide extract without any purification was able to distinguish spectral patterns of transformed and untransformed lines. In particular, several characteristic peaks from m/z 4373 to 4932 were detected only in the mass spectra of GM tuber samples. Copyright © 2003 John Wiley & Sons, Ltd. [source] Predatory hoverflies select their oviposition site according to aphid host plant and aphid speciesENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2007Raki Almohamad Abstract The hoverfly Episyrphus balteatus De Geer (Diptera: Syrphidae) is an abundant and efficient aphid-specific predator. Several aphidophagous parasitoids and predators are known to respond positively to aphid-infested plants. Semiochemicals from the latter association usually mediate predator/parasitoid foraging behavior toward sites appropriate for offspring fitness. In this study, we investigated the effect of aphid host plant and aphid species on foraging and oviposition behavior of E. balteatus. Behavioral observations were conducted using the Noldus Observer v. 5.0, which allows observed insect behavior to be subdivided into different stages. Additionally, the influence of aphid species and aphid host plant on offspring fitness was tested in a second set of experiments. Acyrthosiphon pisum Harris and Megoura viciae Buckton were equally attractive for E. balteatus whereas Aphis fabae Scopoli (all Homoptera: Aphididae) were less attractive. These results were correlated with (i) the number of eggs laid, which was significantly higher for the two first aphid species, and (ii) the fitness of hoverfly larvae, pupae, and adults. Two solanaceous plant species, Solanum nigrum L. and Solanum tuberosum L. (Solanaceae), which were infested with Myzus persicae Sulzer (Homoptera: Aphididae), were also compared using the same approach. Discrimination between these two M. persicae host plants was observed, with S. tuberosum being preferred as an oviposition site by the predatory hoverfly. Larval and adult fitness was correlated with the behavioral observations. Our results demonstrated the importance of the prey,host plant association on the choice of the oviposition site by an aphid predator, which is here shown to be related to offspring fitness. [source] Brackish water subirrigation for vegetables,IRRIGATION AND DRAINAGE, Issue 2 2003R. M. Patel eaux saumâtres; irrigation souterraine; poivron vert; pommes de terre Abstract As freshwater resources for irrigation are being depleted rapidly, recent emphasis has been on the development of nonconventional water sources: reuse of agricultural drainage water, use of industrial or municipal wastewater, and use of brackish water for irrigation. Experiments conducted in field lysimeters over three seasons sought to investigate the feasibility of using brackish water for growing moderately sensitive crops. Brackish waters, with salinity levels of 1, 5 and 9 dS m,1, were used. In 1993 the effects of a factorial combination of three subirrigation water salinity levels, two water table depths and four NPK fertilizer combinations on salt buildup in an initially nonsaline soil and on green pepper (Capsicum annuum L.) performance were assessed. A gradual increase in soil solution salinity (ECsw) from the water table to the soil surface was evident; however, throughout the growing season, the ECsw did not reach a level that could seriously damage the crop. There was no significant difference in pepper yields due to either salinity of subirrigation water or water table depth. In 1994, two potato (Solanum tuberosum L.) cultivars were grown in the soil, which was salinized with 3.5 dS m,1 water before planting tubers. The salt buildup pattern was similar to that observed in 1993; however, the ECsw levels were higher in 1994 due to the higher initial soil salinity. Moreover, a decrease in ECsw was observed near the water table in lysimeters subirrigated with 1 dS m,1 water. For both cultivars, no significant difference in tuber yield was observed due to either water table depth or subirrigation water salinity. In 1995, three potato cultivars were grown in a nonsaline soil as well as a soil presalinized with 2 dS m,1 water. In the topsoil layer, higher rate of increase in ECsw was observed in the saline soil compared to the nonsaline soil. No significant difference in total tuber yield was observed due to either the initial soil salinity levels or subirrigation water salinity levels. Brackish water with salinity levels of up to 9 dS m,1, when applied through subirrigation, could be used to successfully produce green peppers and potatoes under semiarid to arid conditions. Copyright © 2002 John Wiley & Sons, Ltd. RÉSUMÉ Comme les ressources en eau douce utilisées poor l'irrigation s'épuisent rapidement, les récentes recherches tentent de mettre l'emphase sur le développement de sources d'eau non-conventionnelles: la réutilisation de l'eau de drainage agricole, l'utilisation des eaux usées municipales et des eaux saumâtres pour l'irrigation des cultures. Lors de pénuries d'eau douce les eaux saumâtres ont été utilisées pour l'irrigation souterraine de maïs, mais la salinité de la couche supérieur du sol a été réduite en raison de la pluie. Dans les régions arides et semi-arides cette méthode s'est limitée à quelques essais seulement. En raison des quantités limitées d'eau de bonne qualité, on ne peut irriguer de vastes étendues agricoles en régions arides. Or, si l'utilisation des eaux saumâtres s'avérait un succès il serait possible d'améliorer les rendements agricoles. Il est donc nécessaire d'évaluer l'utilisation des eaux saumâtres dans les systèmes d'irrigation souterrains en milieu aride. Des expériences en lysimètres au cours de trois saisons, dans le but d'étudier la faisabilité d'utiliser des eaux saumâtres pour l'irrigation souterraine de cultures moyennement sensibles, furent entreprises en 1993 et 1994. Des eaux saumâtres avec des niveaux de salinité de 1, 5 et 9 dS m,1, furent utilisés. En 1993, les effets d'une combinaison factorielle de trois niveaux de salinité, deux profondeurs de nappe phréatique et quatre combinaisons de fertilisation NPK ont servi à évaluer l'accumulation de sel dans un sol initialement non-salin où le poivron vert (Capsicum annuum L.) a été cultivé. Une augmentation graduelle de la salinité de la solution du sol, de la nappe d'eau souterraine jusqu'à la surface, fut évidente. Bien que durant la saison de croissance, la conductivité électrique de la solution du sol (ECsw) n'ait pas atteint un niveau qui aurait pu endommager sérieusement la culture. Ni les différents niveaux de salinité ni la profondeur de la nappe d'eau souterraine n'ont affecté de façon significative les rendements de poivrons. En 1994, deux cultivars de pommes de terre (Solanum tuberosum L.) furent cultivés dans un sol rendu salin, après avoir été irrigué avec une eau d'un niveau de salinité de 3.5 dS m,1, préalablement à la plantation des tubercules. L'accumulation de sel suivit une tendance semblable à celle observée en 1993. Cependant, les niveaux de ECsw enregistrés en 1994 furent plus élevés en raison du taux de salinité initial plus élevé. De plus, une baisse de ECsw fut observée près de la nappe d'eau souterraine dans les lysimètres irrigués avec une eau d'un niveau de salinité de 1 dS m,1. Ni les différents niveaux de salinité ni la profondeur de la nappe d'eau souterraine n'ont affecté de façon significative le rendement de pommes de terre de chacun des cultivars. En 1995, trois cultivars de pommes de terre ont été cultivés dans un soil non salin ainsi que dans un sol rendu salin au moyen d'une eau avec une conductivité électrique de 2 dS m,1. Dans la couche supérieure du sol, un plus important taux d'augmentation de conductivité électrique a été observé dans le sol salin que dans le sol non salin. Il n'y a pas eu de différence significative observée en raison des taux initiaux de salinité ou encore en raison des taux de salinité de l'eau dans le système d'irrigation souterrain. Cette étude suggère que les eaux saumâtres d'un niveau de salinité jusqu'à 9 dS m,1 pourraient être utilisées dans les systèmes d'irrigation souterrains pour la culture du poivron vert et de la pomme de terre en régions semi-arides et arides. Copyright © 2002 John Wiley & Sons, Ltd. [source] Feeding studies on gynoparae, males and apterous virginoparae of Myzus persicae on potato by electrical penetration graphJOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2004J. T. Margaritopoulos Abstract:, Feeding behaviour of parthenogenetic apterae, post-teneral gynoparae and males of a holocyclic parthenogenetic lineage of Myzus persicae (Sulzer) (Hem., Aphididae) was studied on potato plants, Solanum tuberosum L. (Solanaceae) by DC-electrical penetration graph recording. Differences were observed between morphs during the 7-h recordings, specifically in the first phase of subcuticular probing and in xylem and phloem-related activities. The time required for the first penetration and first cell puncture of the non-vascular tissues was shorter in apterae than in gynoparae and males. Apterae more often showed phloem activities and sustained sap ingestion (100%) than winged morphs (ca. 25%). In addition, phloem ingestion was much longer in apterae than in winged morphs, 3458 s and 25,70 s respectively. In contrast, winged morphs spent 14,21% of the available time ingesting sap from xylem while in apterae xylem sap uptake was only for 2% of the time. Furthermore, the data showed that males perform in general all the feeding behaviours that other conspecific morphs exhibit. The differences in feeding behaviour among morphs of M. persicae are discussed in relation to host specialization and to their possible involvement in non-persistent transmission of viruses. [source] The Effects of Boiling and Leaching on the Content of Potassium and Other Minerals in PotatoesJOURNAL OF FOOD SCIENCE, Issue 5 2008P.C. Bethke ABSTRACT:, The white potato (Solanum tuberosum L.) is a valuable source of potassium in the human diet. While most consumers benefit from high levels of potassium in potato tubers, individuals with compromised kidney function must minimize their potassium intake. This study was undertaken to determine the effects of leaching and boiling on levels of potassium and other minerals in potato tubers. Leaching alone did not significantly reduce levels of potassium or other minerals in tubers. Boiling tuber cubes and shredded tubers decreased potassium levels by 50% and 75%, respectively. Reductions in mineral amounts following boiling were observed for phosphorus, magnesium, sulfur, zinc, manganese, and iron. There was no difference between the leaching and boiling treatment and the boiling treatment. In addition, mineral levels in tubers of 6 North American potato cultivars are reported. Significant differences in mineral levels were detected among cultivars, but they were too small to be nutritionally important. Individuals wishing to maximize the mineral nutrition benefits of consuming potatoes should boil them whole or bake, roast, or microwave them. Those who must reduce potassium uptake should boil small pieces before consuming them. [source] Genotypic variation of potato for phosphorus efficiency and quantification of phosphorus uptake with respect to root characteristicsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 5 2009Tesfaye Balemi Abstract Potato (Solanum tuberosum L.), an important food crop, generally requires a high amount of phosphate fertilizer for optimum growth and yield. One option to reduce the need of fertilizer is the use of P-efficient genotypes. Two efficient and two inefficient genotypes were investigated for P-efficiency mechanisms. The contribution of root traits to P uptake was quantified using a mechanistic simulation model. For all genotypes, high P supply increased the relative growth rate of shoot, shoot P concentration, and P-uptake rate of roots but decreased root-to-shoot ratio, root-hair length, and P-utilization efficiency. Genotypes CGN 17903 and CIP 384321.3 were clearly superior to genotypes CGN 22367 and CGN 18233 in terms of shoot,dry matter yield and relative shoot-growth rate at low P supply, and therefore can be considered as P-efficient. Phosphorus efficiency of genotype CGN 17903 was related to higher P-utilization efficiency and that of CIP 384321.3 to both higher P-uptake efficiency in terms of root-to-shoot ratio and intermediate P-utilization efficiency. Phosphorus-efficient genotypes exhibited longer root hairs compared to inefficient genotypes at both P levels. However, this did not significantly affect the uptake rate and the extension of the depletion zone around roots. The P inefficiency of CGN 18233 was related to low P-utilization efficiency and that of CGN 22367 to a combination of low P uptake and intermediate P-utilization efficiency. Simulation of P uptake revealed that no other P-mobilization mechanism was involved since predicted uptake approximated observed uptake indicating that the processes involved in P transport and morphological root characterstics affecting P uptake are well described. [source] Impact of hot water treatment on sprouting, membrane permeability, sugar content and chip colour of reconditioned potato tubers following long-term cold storageJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2008Marios C Kyriacou Abstract BACKGROUND: The efficacy of hot water treatment in facilitating successful reconditioning of processing potato (Solanum tuberosum L.) cultivar Hermes following 6 months cold storage at 4.5 °C was examined. Tubers were subjected to hot water treatments (HWTs) at 52.5, 55.0, 57.5 and 60.0 °C for 0,60, 0,50, 0,40 and 0,20 min, respectively, and then reconditioned for 20 days at 16 °C before evaluated for sprouting, fresh weight loss, membrane permeability, sugar content and processing quality. RESULTS: The study demonstrates that in order to achieve complete inhibition of sprouting during potato reconditioning HWTs must exceed the thermal tolerance threshold of the tubers. Short-duration HWT was effective in retarding sprout growth and tuber dehydration without significantly affecting storage parenchyma membrane permeability, tuber sugar content or processing quality. On the contrary, prolonged HWT caused extensive heat damage, loss of membrane integrity and induced an increase in tuber sucrose and reducing sugar content resulting in deterioration of chip colour in proportion to treatment duration. CONCLUSION: Although HWT at 52.5,60 °C following long-term cold storage did not improve the processing quality of potato tubers after 20 days of reconditioning, future work is needed to evaluate the effect of short-duration HWT on the permissible extent of reconditioning and subsequent processing quality. Copyright © 2008 Society of Chemical Industry [source] Catalase inhibition alters suberization and wound healing in potato (Solanum tuberosum) tubersPHYSIOLOGIA PLANTARUM, Issue 3 2007Mohammed Bajji In response to wounding, potato (Solanum tuberosum L.) tubers generate hydrogen peroxide (H2O2) in association with suberization, a critical phase of the wound-healing process. In the present study, the effect of aminotriazole (AT), a catalase (CAT, EC 1.11.1.6) inhibitor, on cut tubers was investigated using fresh weight (FW) loss and pathogen attack symptoms as indicators of wound-healing efficiency. Seven days after treatment, AT-treated tuber halves lost more FW and developed infection signs compared with the controls. Thiourea, another CAT inhibitor, as well as exogenous H2O2 treatments induced the same effects as AT suggesting that the alteration of the wound healing may be caused by CAT inhibition and the resulting accumulation of H2O2. Using transgenic tubers, FW losses 1 week after wounding were either higher (CAT repression) or lower (CAT overexpression) than those of the wild-type. When tuber halves were allowed to wound heal for different periods before treatment, AT had no effect on the progress of their wound healing if wound-healed for at least 3 days. This implies that AT may affect early wound-healing-related events, especially those occurring before or during suberization. A time-course analysis of the effects of AT treatment on wounded tuber tissues revealed that AT prevented the deposition of the polyphenolic domain of suberin in association with CAT inhibition and H2O2 accumulation. These data are important in identifying factors that may be required to regulate suberization and contribute to a better understanding of this critical process to hasten its rate and limit wound-related losses in stored potato tubers. [source] Proteomic evaluation of wound-healing processes in potato (Solanum tuberosum L.) tuber tissuePROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 17 2009Inês Chaves Abstract Proteins from potato (Solanum tuberosum L.) tuber slices, related to the wound-healing process, were separated by 2-DE and identified by an MS analysis in MS and MS/MS mode. Slicing triggered differentiation processes that lead to changes in metabolism, activation of defence and cell-wall reinforcement. Proteins related to storage, cell growth and division, cell structure, signal transduction, energy production, disease/defence mechanisms and secondary metabolism were detected. Image analysis of the 2-DE gels revealed a time-dependent change in the complexity of the polypeptide patterns. By microscopic observation the polyalyphatic domain of suberin was clearly visible by D4, indicating that a closing layer (primary suberisation) was formed by then. A PCA of the six sampling dates revealed two time phases, D0,D2 and D4,D8, with a border position between D2 and D4. Moreover, a PCA of differentially expressed proteins indicated the existence of a succession of proteomic events leading to wound-periderm reconstruction. Some late-expressed proteins (D6,D8), including a suberisation-associated anionic peroxidase, have also been identified in the native periderm. Despite this, protein patterns of D8 slices and native periderm were still different, suggesting that the processes of wound-periderm formation are extended in time and not fully equivalent. The information presented in this study gives clues for further work on wound healing-periderm formation processes. [source] A SELDI-TOF MS procedure for the detection, quantitation, and preliminary characterization of low-molecular-weight recombinant proteins expressed in transgenic plantsPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 2 2009M. Amine Badri Abstract We describe a SELDI-TOF MS procedure for the rapid detection and quantitation of low-molecular-weight recombinant proteins expressed in plants. Transgenic lines of potato (Solanum tuberosum L.) expressing the clinically useful protein bovine aprotinin or the cysteine protease inhibitor corn cystatin II were generated by Agrobacterium tumefaciens -mediated transformation, and then used as test material for the analyses. Real-time RT-PCR amplifications and detection of the recombinant proteins by immunoblotting were first conducted for transformed potato lines accumulating the proteins in different cell compartments. Both proteins were found at varying levels in leaves, depending on their final cellular destination and transgene expression rate. These conclusions drawn from standard immunodetection assays were easily confirmed by SELDI-TOF MS comparative profiling, after immobilizing the leaf proteins of control and transformed lines on protein biochips for weak cationic exchange. This procedure, carried out in less than 2,h, allows for the rapid comparison of recombinant protein levels in transgenic plant lines. The molecular weight of immobilized proteins can also be determined directly from the MS spectra, thus providing a simple way to assess the structural integrity and homogeneity of recombinant proteins in planta, and to identify the most suitable cellular compartments for their heterologous production. [source] | |||||||||||||