• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 12
  • 5
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 30
  • 15
  • 11
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Produção de sementes de Lupinus albescens para recuperação de áreas degradadas por arenização / Lupinus albescens seeds production for reclamation of sand degraded areas

Dorneles, Fabiana de Oliveira 28 September 2009 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this work was to evaluate the best sowing time allied to appropriate fertilization levels for the development of Lupinus albescens, seeking seeds production, in sandy area, and also to verify the adaptation of this specie in soils with different clay content from the place of origin. For this, an experiment was carried out in São Francisco de Assis county, on Typic Quartzipsamments soil with experimental units distributed in random blocks design, with subdivided plots, constituted of three seeding times, seven fertilization levels and four replications. Fertilizing management was accomplished with base in the recommendation stipulated for the cultivation of Lupinus spp, according to SBCS (2004), being tested fractions of the dose to supply the crop nutritional needs (phosphorus and potassium) for the place, being applied 0, 25, 50, 75, 100, 125 and 150% of the recommended dose, with the sowing performed in May, June and July of 2008. To test the effect of the clay content on the growing of L. albescens, experimental units were carried out in random blocks design in three different places, with four replications, being the treatments the different soils types: Typic Quartzipsamments (6% of clay), Paleudalf (16% of clay) and Haplortox (48% of clay). At 150 days after seeding, were verified the plants survival index, height of plants and number of legumes per plant. After harvesting, were determined seeds yield and medium weight of 100 seeds. The observation of the results were restricted to the experiments implanted in the months of May and June, developed on sandy soil (degraded area), because L. albescens seeded in July didn t complete its development, fact that also happened in the experiment implanted on Haplortox and Paleudalf, and in this last there wasn t seeds germination. For the plants survival results, it was verified that there was low population of surviving plants, however the seeding in May showed higher medium of survival plants than the seeding done in June, with no statistical differences among the doses of applied fertilizer in the same time. The largest average of height of plants was verified in the treatment of 75% of the fertilizer dose recommended for Lupinus spp, with the crop seeding in May, as well as the results of number of legumes per plant and grain yield, regarding 27,9 legumes for plant and 351,33 kg ha-1 of grains on soil degraded. The verification of the development of L. albescens on soils with different clay content showed that this plant only adapts to sandy soils, with high content of sand, because were obtained 31,65 kg ha-1 of grains on cultivation in degraded soil, differing statistically of the null production on the other soil types. Besides, is concluded that May is the most appropriate time to seed L. albescens, allied to the application of 75% of the fertilizer dose recommended for the cultivation of Lupinus spp, seeking seeds production. / O objetivo deste trabalho foi indicar a melhor época de semeadura aliada à dose adequada de fertilizantes para o desenvolvimento de Lupinus albescens, visando à produção de sementes, em área arenizada. Avaliou-se também a adaptação desta espécie em solos com teores de argila distintos do local de origem da obtenção das sementes nativas de L. albescens. Um experimento foi conduzido no município de São Francisco de Assis, sobre NEOSSOLO QUARTZARÊNICO Distrófico típico. As unidades experimentais foram distribuídas em Delineamento Blocos ao Acaso com parcelas subdividas, constituído de três épocas de semeadura, sete doses de adubação e quatro repetições. O manejo da adubação foi realizado com base na recomendação estipulada para o cultivo de Lupinus spp. Sendo testadas frações da dose calculada para suprir as necessidades nutricionais (fósforo e potássio) da cultura no local, sendo aplicadas 0, 25, 50, 75, 100, 125 e 150% da dose recomendada. A semeadura sendo realizada nos meses de maio, junho e julho de 2008. Para testar o efeito do teor de argila sobre o desenvolvimento de L. albescens, foram conduzidas unidades experimentais em Delineamento Blocos ao Acaso em 3 locais diferentes, com 4 repetições, sendo os tratamentos representados pelos tipos de solos distintos: NEOSSOLO QUARTZARÊNICO Distrófico típico (6% de argila), ARGISSOLO VERMELHO Distrófico arênico (16% de argila) e LATOSSOLO VERMELHO Distrófico típico (48% de argila). Aos 150 dias após a semeadura verificou-se índices de sobrevivência de plantas, altura de plantas e número de vagens por planta. Após a colheita das sementes, foi avaliado o rendimento de sementes e o peso médio de 100 sementes. As observações dos resultados foram restritas aos experimentos implantados nos meses de maio e junho, desenvolvidos sobre solo arenizado, pois não houve desenvolvimento completo da cultura semeada no mês de julho, fato que também ocorreu no experimento implantado sobre Latossolo e Argissolo, sendo que neste último tão pouco houve germinação da semente. Houve baixa população de plantas sobreviventes, entretanto a semeadura no mês de maio apresentou maior média de plantas sobreviventes do que a semeadura realizada em junho, não havendo diferença estatística entre as doses de adubação aplicadas na mesma época. A maior média de altura de plantas foi verificada no tratamento de 75% da dose de adubação recomendada para Lupinus spp, com a semeadura da cultura no mês de maio. Neste período, os resultados de número de vagens por planta e rendimento de sementes, referente a 27, 9 vagens por planta e 351,33 kg ha-1 de sementes sobre solo arenizado. O desenvolvimento de L. albescens sobre solos com diferentes teores de argila mostrou que a cultura se adapta a solos com elevados teores de areia, pois foram obtidos 31,65 kg ha-1 de sementes sobre cultivo em solo arenizado, diferenciando-se estatisticamente da produção nula sobre os demais tipos de solo. Além disto, conclui-se que o mês de maio é a época mais adequada à semeadura de L. albescens aliada à aplicação de 75% da dose de adubação recomendada para o cultivo de Lupinus spp, visando à produção de sementes.
12

Interactions induites par l'association du lupin avec une céréale, effets sur les adventices et conséquences sur la productivité / Interactions resulting from additive intercropping of lupin with a cereal : effects on weeds and productivity

Carton, Nicolas 18 December 2017 (has links)
Les protéagineux pourraient contribuer à réduire le déficit en protéines de l’Europe mais ils sont peu cultivés. L’association à une céréale permettrait de contourner leur variabilité de rendement et leur faible compétitivité vis-à-vis des adventices. Cette stratégie serait particulièrement pertinente pour le lupin blanc d’hiver, qui présente un fort potentiel de production de protéines mais un fort risque d’enherbement. Ce travail de thèse étudie en dynamique les interactions entre lupin, céréale et adventices afin de mettre en évidence les traits des espèces permettant d’accroitre leur complémentarité et la compétitivité vis-à-vis des adventices tout en sécurisant la productivité. L’étude d’un réseau de parcelles démontre que l’ajout de triticale permet d’augmenter la compétitivité vis-à-vis des adventices par rapport au lupin pur, d’obtenir un rendement supérieur et plus stable et de maintenir la production de protéines. Un essai en micro parcelles démontre le rôle majeur de la capture précoce d’azote (N) de la céréale pour accroitre la compétitivité vis-à-vis des adventices. Nous montrons que les rapports de compétition varient au cours du cycle et en fonction des espèces ou variétés ainsi que des conditions climatiques et influencent ainsi l’élaboration du rendement. De forts contrastes entre lupin et céréale pour des traits liés à l’acquisition précoce d’N sont décrits ainsi que leurs conséquences sur la mise en place de la complémentarité. Ce travail met en évidence que le choix d’espèces et de variétés aux traits complémentaires permet d’orienter les interactions entre lupin, céréale et adventices et ouvre des perspectives pour l’optimisation des performances. / Pea, faba bean and lupin could help to reduce the European protein deficit but they are not widely grown. Intercropping with a cereal can be seen as a way to circumvent their high yield variability and their low competitive ability against weeds. This strategy could be particularly relevant for winter white lupin, a crop that can produce high amounts of proteins but that is prone to high weed infestations. This doctoral thesis studies the dynamic interactions between lupin, cereal and weeds to highlight species traits that allow increasing their complementarity and their competitive ability against weeds while securing productivity. Results of a multisite study in agricultural fields demonstrate that adding triticale in lupin allows increasing competitive ability against weeds as well as yield and yield stability compared with sole-cropped lupin while maintaining protein production. A plot experiment highlights the key role of cereal early Nitrogen (N) uptake in the increase of competitive ability against weeds. Analysis of resource sharing shows that competitive relationships vary throughout the cropping cycle, depend on species or cultivars as well as climatic conditions and that they influence yield formation. Strong contrasts between lupin and a cereal for traits related to early soil N uptake and their consequences on complementarity are highlighted by the results of rhizotron experiments. This work emphasizes the role of species and cultivar choice to manage interactions between lupin, cereal and weeds and opens perspectives for the optimization of intercrop performances.
13

Effet de l’exsudation de citrate chez le lupin blanc sur la phytodisponibilité de l’uranium / Effect of citrate exudation in white lupine on uranium phytoavailability

Tailliez, Antoine 08 July 2013 (has links)
L’étude proposée s’inscrit dans un contexte de contamination croissante de la pédosphère et fait le choix d’appréhender cette problématique via une approche centrée sur la rhizospère et sur les mécanismes gouvernant son évolution. Ces travaux s'intéressent à la relation entre l’uranium – un métal naturel ubiquiste non-essentiel – et le citrate – un acide organique de faible poids moléculaire exsudé par certaines espèces végétales poussant sur un milieu pauvre en phosphore. Parmi ces espèces particulières le lupin blanc (Lupinus albus) fait office de plante modèle. Un sol naturellement riche en uranium prélevé à l’affleurement d’une veine de pechblende a été étudié. L’objectif du travail a été de savoir si l’activité racinaire est suffisante pour provoquer la remobilisation de l’uranium dans la solution du sol et favoriser son transfert. Le système sol/plante a été étudié sur rhizotest et de manière découplée en hydroponie et en réacteurs fermés. Il a été démontré que la présence d’uranium dans un milieu contrôlé (hydroponie) stimule l’exsudation de citrate chez les lupins blancs qui ne sont pas carencés en phosphore et que cette exsudation de citrate favorise la solubilisation de l’uranium dans la solution du sol en réacteurs fermés. Ces résultats ont été confirmés par les observations faites sur rhizotest même si les valeurs obtenues dans ce cas étaient plus nuancées. Ceci justifie les approches utilisées et met en évidence leur complémentarité. Les résultats obtenus ont également permis d’apporter des informations concernant la toxicité de l’uranium, son internalisation dans les cellules racinaires ainsi que sur son transfert des racines aux parties aériennes. / The present study is related to the context of pedosphere contamination increasing and chose to consider this issue through a focus on rhizosphere and mechanisms that govern its evolution. This work is oriented on the relation between uranium – a non-essential ubiquitous metal – and citrate – a low molecular weight organic acid exudated by specific species when grown on a phosphorus-deficient environment. Among these particular species white lupine (Lupinus albus) is considered as a model species. Furthermore, a natural soil containing huge amounts of uranium has been collected at the outcrop of a pitchblende vein and used during some experiments. The main aim of this PhD thesis was to determine if the root activity of white lupine is sufficient to cause the remobilization of uranium into soil solution and so to promote the transfer of this contaminant to the plant. The soil/plant system has been studied with rhizotests and by combining datas obtained with hydroponics experiments and batches tests. It has been demonstrated that the presence of uranium in a controlled growth medium (hydropony) stimulates citrate exudation in P-sufficient white lupine. More, this citrate exudation enhances uranium solubilization in soil solution in batches. These results have been confirmed by observations on rhizotest even if the values in this case were more nuanced. This justifies the employed approaches and highlights their coherence and complementarity. The results also allowed to provide additional information concerning uranium toxicity, its internalization in root cells as well as its transfer from roots to aerial parts.
14

Evaluation of two potential management strategies for garden lupin (Lupinus polyphyllus) in road verges / Utvärdering av två potentiella hanteringsmetoder för blomsterlupin (Lupinus polyphyllis) i vägkanter

Blomqvist, Elin January 2021 (has links)
Invasiva växtarter är ett globalt problem som hotar inhemska ekosystem. Blomsterlupinen (Lupinus polyphyllis) är en invasiv flerårig växt som erhåller flera egenskaper som bidrar till dess framgångsrika etablering och spridning. Vägkanter agerar som landskapskorridorer för exotiska arter samtidigt som det är en viktig habitatrefug för många ängsväxter. För att effektivisera bevarandeåtgärder behövs en gedigen kunskap om målarten och dess egenskaper. Syftet med den här studien var att utvärdera två potentiella hanteringsmetoder av blomsterlupin i vägkanter. Slåtter är en redan etablerad strategi, men för att ta reda på om olika skördintensiteter påverkar återväxten av biomassa på olika sätt jämfördes en kontrollgrupp (ej skörd) och tre skördgrupper (1–3 skördar) med avseende på bladbiomassa, stambiomassa, blomställningsbiomassa och plantans totala biomassa. En annan potentiell hanteringsmetod utvärderades med fokus på fröbanken. Frön från blomsterlupin värmebehandlades i 40°C, 50°C och 70°C, och jämfördes mot frön utsatta för kontrolltemperatur (20°C). Varaktigheten för värmebehandlingar var 1, 5 och 15 minuter. Några frön utsattes för vattenbehandling innan värmebehandlingen för att bryta den fysiska vilan. Blomsterlupinfrön jämfördes mot tre andra arter i familjen ärtväxter (Fabaceae); blodklöver (Trifolium incarnatum), blålusern (Medicago sativa) och (Louts corniculatus). Det fanns en signifikant effekt beroende av skördintensitet på återväxt av stambiomassa, blomställningsbiomassa och plantans totala biomassa. Gällande bladbiomassa fanns ingen skillnad mellan grupperna. Faktumet att blomsterlupinen primärt investerar mer resurser på produktion av bladbiomassa kan anses positivt ur ett åtgärdsperspektiv. Återväxten av biomassa var emellertid beroende av plantans ursprungliga storlek, således skulle effekten av slåtter kunna skilja sig mellan individer i en population. Vattenbehandlingen bröt inte den fysiska vilan hos blomsterlupinfrön. Men en ökad temperatur under värmebehandlingen verkade ha en hämmande effekt för antalet grodda frön och MGT. Trots det återfanns ett relativt stort antal levande blomsterlupinfrön efter den sista observationsdagen. Det kan indikera att många frön skulle överleva en värmebehandling av fröbanken om behandlingen skulle implementeras som åtgärdsmetod. Metoden skulle förmodligen vara tidskrävande och dyr i förhållande till den önskade reducerande effekten på levande blomsterlupinfrön. För att utveckla resurseffektiva åtgärder för artens fröbank krävs mer kunskap. Slåtter verkar vara en bättre åtgärdsmetod om det genomförs vid rätt tidpunkt två gånger om året. / Invasive plant species are a global problem that threaten native ecosystems. The garden lupin (Lupinus polyphyllus) is an invasive perennial herb and possesses several traits, which enables successful establishment and dispersal. Road verges serve as landscape corridors for exotic species, as well as being an important refuge habitat for many grassland species. To make conservation managements more efficient, an extensive knowledge of the target species and it’s traits is required. The aim of this study was to evaluate two potential management strategies for garden lupin in road verges. Mowing is an established strategy already, but to find out if different cutting intensities will affect biomass regrowth differently, one control group (no cut) and three harvest groups (1-3 cuts) were compared regarding leaf biomass, stem biomass, inflorescence biomass and total plant biomass. Another potential management strategy was evaluated focusing on the seed bank. Seeds of garden lupin were heat treated at 40 °C, 50 °C, and 70 °C and compared to control seeds (20 °C). Duration of treatments was 1, 5, and 15 minutes. Some seeds were watered before the heat treatment to break physical dormancy. Seeds of garden lupin were compared to three other species in the Fabaceae family: Trifolium incarnatum, Medicago sativa, and Lotus corniculatus. I found a significant effect of cutting frequency on regrowth of stem biomass, inflorescence biomass, and total plant biomass. Regarding leaf biomass, there was no difference between harvest groups. The fact that garden lupin plants primarily invest more resources in leaf biomass regrowth can be regarded as positive from a management point of view. However, biomass regrowth was depended on initial plant size, and the mowing response might differ between individual plants in populations. The water treatment did not break the physical dormancy of garden lupin seeds. Increased temperatures during heat treatments seemed to have an inhibiting effect on both seed germination and mean germination time. However, a high number of vital garden lupin seeds were remaining after the last observation. This might indicate that many seeds would remain vital if seed bank heat treatments were implemented as a management strategy. The strategy would probably be time consuming and expensive in relation to the desired reducing effect on vital garden lupin seeds. To develop resource efficient management actions on the species’ seed bank, more knowledge is needed. Mowing seems like a better management option if it is implemented at the right time twice a year.
15

Uppvärmning som en potentiell metod att bekämpa fröer av blomsterlupin (Lupinus polyphyllus) / Heat treatment as a potential control method for Garden lupine (Lupinus polyphyllus) seeds

Petrachkova, Daria January 2023 (has links)
Blomsterlupin (Lupinus polyphyllus) är en iögonfallande invasiv växtart som i nuläget är spridd över större delen av Sverige utom nordvästra delen av Norrbotten. Framtagande av effektiva bekämpningsmetoder är av stor betydelse eftersom spridning av blomsterlupin hotar känsliga naturhabitat, exempelvis så kallade artrika vägkanter. Detta arbete fokuserar på värmebehandling, en metod som potentiellt kan användas för desinfektion av lösa jordmassor, som anses vara en av de största spridningsvektorerna för blomsterlupin. Arbetets syfte är att med hjälp av uppsamlade data undersöka om det finns en optimal temperatur och exponeringstid för effektiv minskning av antalet grodda blomsterlupinfrö. Utöver detta, utvärderas effekterna av förbehandling i form av rispning och blötläggning av frön. Inom experimentet behandlades blomsterlupinfrö med olika temperatur under olika exponeringstid. Hälften av fröna fick förbehandling i form av blötläggning efter rispning av skalet inför uppvärmningen. Frön värmebehandlades i 88˚C, 93˚C, 98˚C och 103˚C under 1, 3, 5 och 10 minuters tid. Efter värmebehandlingen fick fröna gro i ett odlingskåp. Resultatet visar att förbehandling, ökad temperatur och ökad exponeringstid bidrar till signifikant minskning av andel grodda blomsterlupinfrö. Ju högre temperaturen var, desto större var effekten av längre exponeringstid. Effekten av hög temperatur och lång exponeringstid var starkare om fröna var förbehandlade. Resultatet tyder på att värmebehandling potentiellt är en effektiv metod för bekämpning av blomsterlupinfrö. Vidare experiment krävs för att undersöka hur denna metod kan effektiviseras och tillämpas i praktiken, i synnerhet vid uppvärmning av stora volymer av jordmassor. / Garden lupine (Lupinus polyphyllus) is an eye-catching invasive herb that is currently spread over the major part of Sweden except for the northwestern part of Norrbotten county. The development of effective control methods is of great importance because the spread of Garden lupine threatens sensitive natural habitats, for example species rich road verges. This work focuses on heat treatment, a method that can potentially be used for the disinfection of soil masses, which is considered one of the major dispersal vectors for Garden lupine. The purpose of this work is to use the collected data to investigate whether there is an optimal temperature and duration of exposure for effective reduction of the number of germinated Garden lupine seeds. In addition, this work evaluates the effects of pre-treatment in the form of scarifying and soaking of seeds. Within the experiment, Garden lupine seeds were treated with different temperatures and different duration of exposure. Half of the seeds received pre-treatment in the form of soaking after scarifying the seed coat before heating. After that, seeds were heat treated at 88˚C, 93˚C, 98˚C and 103˚C for 1, 3, 5 and 10 minutes. After the heat treatment, the seeds were allowed to germinate in a growth chamber. The result shows that pre-treatment, increased temperature and increased exposure time contribute to a significant reduction in the percentage of germinated Garden lupine seeds. The higher the temperature, the stronger was the effect of a longer exposure time. The effect of high temperature and long exposure time was stronger if the seeds were pre-treated. The result suggests that the heat treatment is potentially an effective control method for Garden lupine seed. Further experiments are required to investigate if this method could be made more efficient and applied in practice, particularly when heating large volumes of soil masses.
16

Quantifying landscape metrics to analyse the threat to species-rich road verges from Lupinus polyphyllus / Kvantifiering av landskapsmått för att analysera hotet mot artrika vägkanter från Lupinus polyphyllus

Svantesson, Maria January 2022 (has links)
In Sweden, the garden lupine (Lupinus polyphyllus) has a negative effect on the native flora and fauna as it is a highly competitive plant, with high dispersal and growth rates and nitrogen-fixing ability. Landscape metrics are important tools to analyse and understand landscape structure, and could also support the planning of control measures for the invasive lupine. The aim of this study was to use a modelling analysis to evaluate fifty study areas with varying lupine density, ranging from single or sparse to dense or dominant. Several landscape metrics were used to quantify the frequency of lupine presence, and to try to quantify the threat for the modelled species-rich road verges. The study aim was to assess which landscape metrics could predict the weighted mean area of lupine. The research questions in this study were “is there a correlation between different landscape metrics and the weighted mean area of lupine stands?” and “how well can different landscape metrics quantify the threat for road verge communities , in terms of the amount of lupines in the landscape?”. The study area is located in the Heby-region, Uppland (Sweden). Bivariate linear regression was used to test if the mean length, Proximity (Px), distance to nearest neighbour or the number of lupine stands had any significant relation to the weighted mean area. The results showed a significant relationship between the weighted mean area and the mean length of the lupine stands (R²=0.366) and between the weighted mean area and the Px (R²=0.117). This analysis shows that, when data of lupine density are not available, mean stand length and Px might be suitable alternatives. Using this method could assist the work of prioritizing which invaded areas to manage. The method might also be cost-and time-efficient when data of lupine density is unavailable. / I Sverige har trädgårdslupinen (Lupinus polyphyllus) en negativ effekt på den inhemska floran och faunan då det är en mycket konkurrenskraftig växt, med hög spridnings- och tillväxthastighet och kvävebindande förmåga. Landskapsmått är viktiga verktyg för att analysera och förstå landskapets struktur, och skulle också kunna stödja planeringen av bekämpningsåtgärder av den invasiva lupinen. Syftet med studien var att använda en modelleringsanalys för att utvärdera femtio studieområden med varierande lupintäthet, från enstaka eller glesa till täta eller dominerande. Flera landskapsmått användes för att kvantifiera frekvensen av lupinförekomst och för att försöka kvantifiera hotet för de modellerade artrika vägkanterna. Studiens syfte var att bedöma vilka landskapsmått som kunde förutsäga den viktade medelarean för lupinbestånden. Forskningsfrågorna i denna studie var "finns det ett samband mellan olika landskapsmått och den viktade medelarean för lupinbestånd?" och "hur väl kan olika landskapsmått kvantifiera hotet för artrika vägkanter, i fråga om mängden lupiner i landskapet?". Studieområdet är beläget i Heby-regionen, Uppland (Sverige). Bivariat linjär regression användes för att testa om medellängden, Proximity (Px), avståndet till närmsta lupinbestånd eller antalet lupinbestånd hade ett signifikant samband till lupinbeståndens viktade medelarea. Resultaten visade ett signifikant samband mellan den viktade medelarean och medellängden av lupinbestånden (R²=0,366) och mellan den viktade medelarean och Px (R²=0,117). Analysen visar att, när data om lupinbeståndens täthet inte finns tillgängliga, kan lupinbeståndens medellängd och Px vara lämpliga alternativ. Att använda denna metod skulle kunna underlätta arbetet med att prioritera vilka invaderade områden som ska förvaltas. Metoden kan också vara kostnads- och tidseffektiv när data om lupintäthet inte finns tillgänglig.
17

Variation i blomsterlupinens (Lupinus polyphyllus) tillväxt och fenologi i dess invasiva utbredningsområde i Europa / Variation in the growth and phenology of the garden lupin (Lupinus polyphyllus) in its invasive range in Europe

Kaukoranta, Vilma January 2020 (has links)
Den invasiva blomsterlupinens (Lupinus polyphyllus) spridning i Sverige är ett hot mot många inhemska växtarters överlevnad. Det är oklart hur den pågående globala uppvärmningen kan komma påverka artens invasionsframgångar. I det här kandidatarbetet har jag därför studerat hur blomsterlupinens tillväxt och fenologi varierar längs latitud i Europa i syfte med att avgöra om arten visar fitnesskillnader beroende på temperatur. Tjugo populationer från Trier (Tyskland) i söder till Umeå (Sverige) i norr följdes under en växtsäsong och data på blomsterlupinplantornas höjd samt blomställningarnas längd samlades in. Regressionsanalysen visade att det inte fanns något signifikant skillnad mellan latitud och ovanjordisk biomassa eller blomställningens längd. Däremot utvecklades den reproduktiva biomassan tidigare i växtsäsongen i de lägre breddgraderna i Europa jämfört med de högre. Studien ger en indikation om att ett varmare klimat kan ha en viss positiv påverkan på blomsterlupinens reproduktion och spridning. De lokala mikroklimatiska effekterna verkar dock ha en stor påverkan på dess relativa fitness, vilket betyder att vissa populationer kan gynnas mer än andra. Utbredningsområdet kan komma utökas mer norrut när stigande temperaturer och färre frostdagar gör nya områden tillgängliga för arten. / The spread of the invasive garden lupin (Lupinus polyphyllus) in Sweden threatens the survival of many native plant species. It is unclear how ongoing global warming may affect the species' invasion success. In this Bachelors essay I have therefore studied how the growth and phenology of the garden lupin varies with latitude in Europe to determine if the species shows any fitness differences depending on the temperature. Twenty garden lupin populations from Trier (Germany) in the south to Umeå (Sweden) in the north were followed during a single growing season and data on the plant’s height and the length of the inflorescences were collected. Regression analysis showed that there was no relationship between latitude and aboveground biomass or length of inflorescence. Reproductive biomass, on the other hand, developed earlier in the growing season at lower latitudes than at higher ones. The study indicates that a warmer climate may have a positive effect on the reproduction and spread of the garden lupin. Local microclimatic effects appear to have a major impact on its relative fitness though, which means that some populations may benefit more than others. The species’ range may expand further north as rising temperatures and fewer frost days make new areas available for the species.
18

Effects of long- and short-term crop management on soil biological properties and nitrogen dynamics

Stark, Christine January 2005 (has links)
To date, there has been little research into the role of microbial community structure in the functioning of the soil ecosystem and on the links between microbial biomass size, microbial activity and key soil processes that drive nutrient availability. The maintenance of structural and functional diversity of the soil microbial community is essential to ensure the sustainability of agricultural production systems. Soils of the same type with similar fertility that had been under long-term organic and conventional crop management in Canterbury, New Zealand, were selected to investigate relationships between microbial community composition, function and potential environmental impacts. The effects of different fertilisation strategies on soil biology and nitrogen (N) dynamics were investigated under field (farm site comparison), semi-controlled (lysimeter study) and controlled (incubation experiments) conditions by determining soil microbial biomass carbon (C) and N, enzyme activities (dehydrogenase, arginine deaminase, fluorescein diacetate hydrolysis), microbial community structure (denaturing gradient gel electrophoresis following PCR amplification of 16S and 18S rDNA fragments using selected primer sets) and N dynamics (mineralisation and leaching). The farm site comparison revealed distinct differences between the soils in microbial community structure, microbial biomass C (conventional > organic) and arginine deaminase activity (organic > conventional). In the lysimeter study, the soils were subjected to the same crop rotation (barley (Hordeum vulgare L.), maize (Zea mays L.), rape (Brassica napus L. ssp. oleifera (Moench)) plus a lupin green manure (Lupinus angustifolius L.) and two fertiliser regimes (following common organic and conventional practice). Soil biological properties, microbial community structure and mineral N leaching losses were determined over 2½ years. Differences in mineral leaching losses were not significant between treatments (total organic management: 24.2 kg N per ha; conventional management: 28.6 kg N per ha). Crop rotation and plant type had a larger influence on the microbial biomass, activity and community structure than fertilisation. Initial differences between soils decreased over time for most biological soil properties, while they persisted for the enzyme activities (e.g. dehydrogenase activity: 4.0 and 2.9 µg per g and h for organic and conventional management history, respectively). A lack of consistent positive links between enzyme activities and microbial biomass size indicated that similarly sized and structured microbial communities can express varying rates of activity. In two successive incubation experiments, the soils were amended with different rates of a lupin green manure (4 or 8t dry matter per ha), and different forms of N at 100 kg per ha (urea and lupin) and incubated for 3 months. Samples were taken periodically, and in addition to soil biological properties and community structure, gross N mineralisation was determined. The form of N had a strong effect on microbial soil properties. Organic amendment resulted in a 2 to 5-fold increase in microbial biomass and enzyme activities, while microbial community structure was influenced by the addition or lack of C or N substrate. Correlation analyses suggested treatment-related differences in nutrient availability, microbial structural diversity (species richness or evenness) and physiological properties of the microbial community. The findings of this thesis showed that using green manures and crop rotations improved soil biology in both production systems, that no relationships existed between microbial structure, enzyme activities and N mineralisation, and that enzyme activities and microbial community structure are more closely associated with inherent soil and environmental factors, which makes them less useful as early indicators of changes in soil quality.
19

Effects of lupin kernel flour on satiety and features of the metabolic syndrome

Lee, Ya Ping January 2008 (has links)
[Truncated abstract] Obesity is now a major public health problem worldwide. More than half the Australian population is now overweight. This is an important public health concern primarily because of the impact of overweight and obesity on risk of diabetes, hypertension and cardiovascular disease. Many strategies have been proposed to fight the obesity epidemic. One possible strategy involves understanding of the role of dietary components in the control of food intake. In this regard, dietary protein and fibre appear to be the most satiating nutrients. Foods enriched in protein, replacing energy from carbohydrate, or dietary fibre can increase satiety and reduce energy intake in the short-term. Longer-term trials suggest benefits of increasing protein or fibre intake on weight loss and features of the metabolic syndrome. The effects of dietary approaches which increase both protein and fibre at the expense of refined carbohydrate are uncertain. A practical approach to increasing both protein and fibre content of processed foods is to incorporate high protein and fibre ingredients into high carbohydrate foods. Lupin kernel flour is a novel food ingredient derived from the endosperm of lupin. It contains 40 to 45% protein, 25 to 30% fibre, and negligible sugar and starch. Lupin kernel flour can be incorporated into refined carbohydrate rich foods such as bread to increase protein and fibre content at the expense of refined carbohydrate. ... Body weight was measured every 2 weeks throughout the 16 week intervention, and these data were analysed to determine whether there was any between group difference in the rate of change in weight over 16 weeks. Over 16 weeks, lupin bread compared to white bread resulted in a significant increase in protein (13.7 (2.3, 25.0) g/d) and fibre (12.5 (8.8, 16.2) g/d) intakes, and a decrease in carbohydrate intake (-19.9 (-45.2, 5.5) g/d). There was a significant difference between groups in the rate of weight change over the 16 weeks (P=0.05). However, at 16 weeks there was no significant effect on body weight (-0.4 (-1.3, 0.6) kg), fat mass (-0.5 (-1.2, 0.2) kg) or fat free mass (0.2 (-0.5, 0.8) kg). Plasma adiponectin and leptin were not altered. Mean 24 hour systolic blood pressure (-2.4 (-3.4, -1.3) mm Hg) and pulse pressure (-3.1 (-3.9, -2.3) mm Hg) were lower for lupin relative to white bread, but diastolic blood pressure was not significantly different between groups. Apart from a lower HDL cholesterol for lupin relative to white bread (-0.09 (-0.17, -0.01) mmol/L), there were no significant differences in other blood lipids and glucose and insulin concentrations. Interpretation of the results was not influenced after adjustment for potential confounding factors. These studies assessed effects of bread enriched in lupin kernel flour relative to white bread, resulting in a higher protein and fibre intake and lower refined carbohydrate intake. This increased satiety and reduced energy intake acutely, but did not significantly influence body weight over 16 weeks. Systolic blood pressure and pulse pressure were significantly reduced. There were no significant improvements in blood lipids or glucose and insulin concentrations. Therefore, increasing protein and fibre intake at the expense of refined carbohydrate using lupin kernel flour may benefit satiety and blood pressure. Longer-term trials incorporating weight loss may be needed to observe benefits on body weight.
20

Etude génétique et physiologique de l'architecture déterminée chez le lupin blanc d'hiver. Conséquences agronomiques et en sélection

Julier, Bernadette 21 January 1994 (has links) (PDF)
Comme chez de nombreux protéagineux, l'architecture déterminée a semblé une voie prometteuse pour réduire le développement végétatif et améliorer le rendement et la stabilité du rendement du lupin blanc d'hiver (Lupinus albus L.). Une étude à la fois génétique et physiologique de ce type architecturale et de ses conséquences sur le développement et la mise en place du rendement a donc été entreprise. L'hérédité du caractère d'architecture déterminée est monogénique récessive, ce qui permet une utilisation simple en sélection. Le développement végétatif est réduit car tous les bourgeons passent à l'état floral précocément dans le cycle. Les ramifications portent chacune moins de feuilles que chez les indéterminés, et le nombre de niveaux végétatifs est réduit. La distribution des feuilles sur les ramifications suit un profil caractéristique en forme de cloche. La structure des ramifications a pu être modélisée. Il existe une grande variabilité génétique pour l'architecture, bien que la relation positive entre tardiveté de floraison et développement végétatif soit forte. L'interception de la lumière par le couvert en fonction du temps est similaire chez les déterminés et les indéterminés. Cependant, les déterminés atteignent une interception maximale moins importante en raison de leur développement végétatif restreint. La proportion de lumière qui parvient jusqu'aux feuilles de la tige principale est accrue. Le rendement des génotypes déterminés semble compétitif avec celui des génotypes indéterminés. La production de matière sèche est plus faible mais l'indice de récolte est supérieur. La date de maturité est sensiblement avancée, surtout sous des climats frais et humides, et la stabilité du rendement est plus grande. Ces caractéristiques sont liées à la réduction du développement végétatif, et à une compétition entre développement végétatif et développement reproducteur plus faible que celle observée chez les indéterminés. Le rendement est produit essentiellement sur la tige principale et le premier niveau de ramifications, et ces sites sont moins sujets à des aléas climatiques que les niveaux supérieurs. La variabilité génétique pour les composantes du rendement est large. On met en évidence des relations entre certains caractères d'architecture et les potentialités de rendement. Un développement végétatif trop restreint aussi bien qu'un développement excessif nuisent au rendement. Les caractères de développement des ramifications (nombre de feuilles et nombre de niveaux végétatifs) sont des critères de sélection pertinents chez les lupins déterminés.

Page generated in 0.0262 seconds