Thesis--Bonn University.

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The generally low concentrations of P and N in the soil, causes most plants to experience nutrient deficiency during their life cycle. Lupins can rely on both cluster roots and nodules for P acquisition and biological nitrogen fixation (BNF) respectively. The legume Lupinus albus is able to survive under low nutrient conditions, because it has two specialized belowground organs for the acquisition of N and P. In this regard, cluster roots increase P uptake and root nodules acquire atmospheric N2 via biological nitrogen fixation (BNF). Although these organs normally tolerates low P conditions, very little is known about their physiological and metabolic flexibility during variations in P supply. Furthermore, the resource allocation (C, N and P) between cluster roots and nodules has also been largely understudied. The aim of this investigation was therefore to determine the resource allocation, physiological and metabolic flexibility of these organs during variations in P supply. Although variation on P supply had no effect on the total biomass, there were significant differences in specialised below-ground organ allocation to cluster roots and nodule formation. Cluster root formation and the associated C-costs increased during low P supply. In contrast to the cluster root decline at high P supply, there was an increase in nodule growth allocation and corresponding C-costs. Since cluster roots were able to increase P acquisition under low P conditions, this below-ground investment may also have benefited the P nutrition of nodules. These findings provide evidence that when lupins acquire N via BNF in their nodules, there may be a trade-off in resource allocation between cluster roots and nodules. The short-term elevated P supply, caused an increased allocation of C and respiratory costs to nodules, at the expense of cluster roots. This alteration was also reflected in the increase in nodule enzyme activities related to organic acid synthesis, such as Phosphoenol-pyruvate Carboxylase (PEPC), Pyruvate Kinase (PK), Malate Dehydrogenase (NADH-MDH) and Malic Enzyme (ME). In cluster roots, the elevated P conditions, caused a decline in these organic acid synthesizing enzymes. This suggests that during short-term elevated P supply, there is a great degree of physiological and metabolic flexibility in the lupin nutrient acquiring structures. / AFRIKAANSE OPSOMMING: Die algemeen lae konsentrasies van fosfaat en stikstof in die grond , veroorsaak dat die meeste plante voedingstekorte ervaar tydens hul lewensiklus. Lupiene kan staatmaak op beide groep-wortels en wortel-knoppies vir P verkryging en biologiese stikstofbinding onderskeidelik. Die peulplant Lupinus albus is in staat om te oorleef onder lae voedings toestande , as gevolg van die twee gespesialiseerde ondergrondse organe vir die verkryging van stikstof en fosfaat. In hierdie verband verhoog groep-wortels fosfaat opname en wortel-knoppies verkry atmosferiese stikstof via biologiese stikstofbinding. Alhoewel hierdie organe normaalweg lae fosfaat toestande verdra , is baie min bekend oor hul fisiologiese en metaboliese buigsaamheid tydens variasies in fosfaat aanwending. Daar is verder ‘n tekort aan die studie van hulpbron toekenning tussen groep-wortels en wortel-knoppies. Die doel van hierdie ondersoek was dus om die toekenning van hulpbronne , fisiologiese en metaboliese buigsaamheid van hierdie organe tydens variasies in fosfaat aanwending te bepaal. Variesie in fosfaat verskaffing het geen invloed op die totale plant biomassa gehad nie, maar daar was wel ‘n beduidende verskil in gespesialiseerde ondergrondse toekenning tussen groep- wortels en wortel-knoppies. Groep-wortel vorming en die gepaardgaande koolstof koste het toegeneem met lae fosfaat verskaffing. In teenstelling met die groep-wortel daling met hoë fosfaat verskaffing, was daar 'n toename in groei van wortel-knoppies en die ooreenstemmende koolstof koste daarvan. Aangesien groep-wortels in staat was om fosfaat verkryging te verhoog onder lae fosfaat toestande, mag hierdie ondergrondse belegging bygedra het tot die voeding van wortel-knoppies . Hierdie bevindings bewys dat lupiene afhanklik van wortel-knoppies ‘n wisselwerking in toekenning van hulpbronne, tussen groep-wrotels en wortel-knoppies handaaf. Kort termyn verhoogde fosfaat aanwending veroorsaak 'n verhoogde toekenning van koolstof en respiratoriese energie na wortel-knoppiess, ten koste van groep-wortels . Hierdie verandering is ook weerspieël in die toename in wortel-knoppie ensiem aktiwiteit in verband met organiese suur sintese (PEPC PK,MDH,ME) . In groep-wortels, het die verhoogde P toestande verder 'n afname in die organiese suur produserende ensieme veroorsaak. Dit dui aan dat tydens kort termyn verhoogde P aanwending, daar 'n groot mate van fisiologiese en metaboliese buigsaamheid in die lupiene voedingstowwe verkryging strukture plaasvind.

Chitinases are a diverse family of proteins occurring in plants. Their function varies considerably, with certain chitinases having been associated with development. The majority however, are pathogenesis related (PR) proteins that have been shown to play a role during plant pathogen interactions. This has lead to many investigations on the use of chitinases in providing transgenic disease resistance. These studies are usually done using a constitutive expression system. This however stands in contrast with the natural defense system were PR gene expression is usually only upregulated when the plant is exposed to abiotic and/or biotic stress factors. The constitutive expression is therefore not ideal as it increases ‘cost’ penalties due to the energy being spent expressing the gene. In this study however, an inducible expression system was applied using a stress inducible promoter AtGSTF6 derived from Arabidopsis thaliana, to drive Lupinus albus IF3 chitinase expression when the plants are under pathogen attack. The construct AtGSTF6-IF3 was inserted into the binary vector pCAMBIA 2300 and transformed into Nicotiana Tabacum cv JR6 by Agrobacterium-mediated transformation. To demonstrate the functionality of such a construct, an expression study was done on transgenic N. Tabacum to determine transcription and in vitro chitinase enzyme activity. The data revealed that IF3 chitinase gene transcription from lupin plants was achieved in N. Tabacum. Nine of the twelve lines that tested positive for chitinase gene transcription after hydrogen peroxide treatment, showed increased chitinase activity. With the success of showing increased chitinase activity, these lines were subjected to a detached leaf assay with Rhizoctonia solani AG2, which causes leaf target spot disease. The assay showed that six of the nine lines identified as having increased chitinase activity showed reductions in lesion areas. More specifically, three of the four lines showing more than a five-fold increase in chitinase activity compared to the untransformed N. Tabacum, showed significant lesion reduction. The AtGSTF6-IF3 construct can therefore be recommended to increase disease resistance in N. Tabacum towards Rhizoctonia solani AG2 after showing both expression and increased disease resistance in certain transgenic lines. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Plant Science / unrestricted

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.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-23T17:01:38Z No. of bitstreams: 1 2013 - L?lian Guimar?es de Almeida.pdf: 713686 bytes, checksum: 57c134f17845f669da63a2f32063c483 (MD5) / Made available in DSpace on 2018-11-23T17:01:38Z (GMT). No. of bitstreams: 1 2013 - L?lian Guimar?es de Almeida.pdf: 713686 bytes, checksum: 57c134f17845f669da63a2f32063c483 (MD5) Previous issue date: 2013-07-22 / CAPES / The objective of this study was to evaluate the imbibition and white lupine seeds physiological quality as affected by the pre-sowing treatments using immersion on the solutions with distinct micronutrients. The experimental design was conducted in a completely randomized in factorial (3 lots x 7 treatments) with four replications, by period of evaluation (start and after four months of storage). There were used three white lupine seed lots and seven distinct pre-sowing treatments (soaked or not soaked seeds on distilled water and in solution of boric acid (H3BO3), zinc sulphate (ZnSO4), manganese sulphate (MnSO4), copper sulphate (CuSO4), and molybdic acid (H2MoO4)). The seeds were evaluated to the imbibition and subsequently were submitted to the germination and vigor tests (first count of germination and electrical conductivity, dry weight and length of seedlings), as well the determinate of the seeds nutrients content. From the results it can be concluded that there was decreased speed of water absorption in the seed lot with lower physiological quality in the presence of manganese and molybdenum. Seed treatment by immersion in distilled water and in solutions of micronutrients favored physiological seed quality of three lots of white lupine. / O objetivo do trabalho foi avaliar a embebi??o e a qualidade fisiol?gica de sementes de tremo?o branco ap?s terem sido submetidas ao tratamento de pr?-semeadura por imers?o em solu??es de micronutrientes. O delineamento experimental adotado foi o inteiramente casualizado, em esquema fatorial (3 lotes x 7 tratamentos), com quatro repeti??es, por per?odo de avalia??o (inicial e ap?s quatro meses de armazenamento). Foram utilizados tr?s lotes de sementes de tremo?o branco e sete distintos tratamentos de pr?-semeadura (sementes imersas ou n?o em ?gua destilada e em solu??o contendo ?cido b?rico (H3BO3), sulfato de zinco (ZnSO4), sulfato de mangan?s (MnSO4), sulfato de cobre (CuSO4) e ?cido mol?bdico (H2MoO4)). As sementes foram avaliadas quanto ? embebi??o e, em seguida, submetidas aos testes de germina??o e de vigor (primeira contagem e condutividade el?trica, comprimento e massa de pl?ntulas) bem como ? avalia??o do teor de nutrientes. Pelos resultados pode-se concluir que houve diminui??o da velocidade de absor??o de ?gua nas sementes do lote com menor qualidade fisiol?gica inicial, na presen?a de mangan?s e molibd?nio. O tratamento de sementes via imers?o em ?gua destilada e em solu??es de micronutrientes favoreceu a qualidade fisiol?gica das sementes dos tr?s lotes de tremo?o branco.

Made available in DSpace on 2014-06-11T19:23:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-05-13Bitstream added on 2014-06-13T19:50:24Z : No. of bitstreams: 1 botaro_ja_me_arafcf.pdf: 1079828 bytes, checksum: e3d6aa320e7262e913df25c024a8740c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Recentemente, a indústria de alimentos está preocupada em desenvolver novos produtos, usando ingredientes inovadores, que promovam benefícios à saúde. O uso de proteínas de leguminosas como uma alternativa para a proteína animal tem sido estudada. O tremoço branco (Lupinus albus L.) apresenta elevada concentração de proteína e óleo, principalmente ácidos graxos insaturados e poliinsaturados, fibra alimentar, açúcares e vitaminas B1 e B2. Por outro lado, o tremoço não pode ser consumido diretamente porque possui alcaloides, que além de serem tóxicos, atribuem gosto amargo ao grão. Como a maioria dos alcaloides é solúvel em água, a quantidade de alcaloide do grão pode ser diminuída através de água corrente, fervente ou salmoura. Sucos de frutas são bastante consumidos no Brasil, especialmente no verão, não somente pelo sabor, mas como fonte de hidratação e por serem ricos em nutrientes. Os sucos de frutas tropicais conquistam cada vez mais o mercado consumidor, sendo o Brasil, um dos principais produtores. A pitanga, fruto da pitangueira (Eugenia uniflora L.) é uma planta frutífera nativa do Brasil (das regiões Sul e Sudeste e que tem se adaptado favoravelmente às condições climáticas e edáficas da região Nordeste), da Argentina e do Uruguai. A pitanga é uma fruta cuja polpa apresenta excelentes condições para industrialização, devido ao seu alto rendimento, aroma agradável e sabor exótico. O objetivo do presente estudo foi o de verificar, através da metodologia de superfície de resposta, as melhores condições para a utilização simultânea de extrato aquoso de tremoço branco e de suco tropical de pitanga, no desenvolvimento de uma bebida. Para tanto, as variáveis independentes foram representadas pelo volume de extrato aquoso de tremoço (mL) e pelo volume de suco de pitanga... / Recently, the food industry is concerned about developing new products, using innovative ingredients that promote health benefits. The use of vegetable protein as an alternative to animal protein is being studied. The white lupine (Lupinus albus L.) has high concentrations of protein and oil, especially non saturated fatty acids and polynonsaturated fats, dietary fiber, sugars and vitamins B1 and B2. On the other hand, the lupine bean can’t be consumed straight because it has alkaloids which besides being toxic, add a bitter taste to the bean. As most alkaloids are water soluble, the amount of alkaloid in the beans can be reduced by running water, boiling or brine. Fruit juices are widely consumed in Brazil, especially in the summer, not only for their flavor, but as a source of hydration and because they are rich in nutrients. The tropical fruit juices are conquering the market more and more, with Brazil being one of the main producers in the world. The Pitanga (Eugenia uniflora L.) is the fruit of the Pitangueira, a native plant of southern Brazil (which has adapted positively to weather and soil conditions in the country’s Northeast), Argentina and Uruguay. Pitanga is a fruit which pulp presents excellent conditions for industrialization, due to its high yield, pleasant aroma and exotic flavor. The aim of the present study was to verify, through the response surface methodology, the optimum conditions for the combined use of aqueous extract of white lupine and tropical pitanga juice in the development of a drink. Therefore, the independent variables were represented by the volume of aqueous extract of lupine (mL) and by the volume of pitanga juice (mL). The dependent variables (responses) were obtained through sensory test of acceptance (appearance, aroma, taste and overall acceptability). The combined... (Complete abstract click electronic access below)

Orientador: José Paschoal Batistuti / Banca: Rubens Monti / Banca: Alice Yoshiko Tanaka / Resumo: Recentemente, a indústria de alimentos está preocupada em desenvolver novos produtos, usando ingredientes inovadores, que promovam benefícios à saúde. O uso de proteínas de leguminosas como uma alternativa para a proteína animal tem sido estudada. O tremoço branco (Lupinus albus L.) apresenta elevada concentração de proteína e óleo, principalmente ácidos graxos insaturados e poliinsaturados, fibra alimentar, açúcares e vitaminas B1 e B2. Por outro lado, o tremoço não pode ser consumido diretamente porque possui alcaloides, que além de serem tóxicos, atribuem gosto amargo ao grão. Como a maioria dos alcaloides é solúvel em água, a quantidade de alcaloide do grão pode ser diminuída através de água corrente, fervente ou salmoura. Sucos de frutas são bastante consumidos no Brasil, especialmente no verão, não somente pelo sabor, mas como fonte de hidratação e por serem ricos em nutrientes. Os sucos de frutas tropicais conquistam cada vez mais o mercado consumidor, sendo o Brasil, um dos principais produtores. A pitanga, fruto da pitangueira (Eugenia uniflora L.) é uma planta frutífera nativa do Brasil (das regiões Sul e Sudeste e que tem se adaptado favoravelmente às condições climáticas e edáficas da região Nordeste), da Argentina e do Uruguai. A pitanga é uma fruta cuja polpa apresenta excelentes condições para industrialização, devido ao seu alto rendimento, aroma agradável e sabor exótico. O objetivo do presente estudo foi o de verificar, através da metodologia de superfície de resposta, as melhores condições para a utilização simultânea de extrato aquoso de tremoço branco e de suco tropical de pitanga, no desenvolvimento de uma bebida. Para tanto, as variáveis independentes foram representadas pelo volume de extrato aquoso de tremoço (mL) e pelo volume de suco de pitanga... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Recently, the food industry is concerned about developing new products, using innovative ingredients that promote health benefits. The use of vegetable protein as an alternative to animal protein is being studied. The white lupine (Lupinus albus L.) has high concentrations of protein and oil, especially non saturated fatty acids and polynonsaturated fats, dietary fiber, sugars and vitamins B1 and B2. On the other hand, the lupine bean can't be consumed straight because it has alkaloids which besides being toxic, add a bitter taste to the bean. As most alkaloids are water soluble, the amount of alkaloid in the beans can be reduced by running water, boiling or brine. Fruit juices are widely consumed in Brazil, especially in the summer, not only for their flavor, but as a source of hydration and because they are rich in nutrients. The tropical fruit juices are conquering the market more and more, with Brazil being one of the main producers in the world. The Pitanga (Eugenia uniflora L.) is the fruit of the Pitangueira, a native plant of southern Brazil (which has adapted positively to weather and soil conditions in the country's Northeast), Argentina and Uruguay. Pitanga is a fruit which pulp presents excellent conditions for industrialization, due to its high yield, pleasant aroma and exotic flavor. The aim of the present study was to verify, through the response surface methodology, the optimum conditions for the combined use of aqueous extract of white lupine and tropical pitanga juice in the development of a drink. Therefore, the independent variables were represented by the volume of aqueous extract of lupine (mL) and by the volume of pitanga juice (mL). The dependent variables (responses) were obtained through sensory test of acceptance ("appearance", "aroma", "taste" and "overall acceptability"). The combined... (Complete abstract click electronic access below) / Mestre

[Truncated abstract] The phloem long distance translocation system is not only involved in the transport of nutrients and photo-assimilates to different organs of the plant, but it also appears to be important for the transport of information molecules including growth-regulators, proteins and RNA. Translocation of signals appears to be involved in the coordination of developmental processes and also in the response of the plant to environmental cues. Much of the information about macromolecules in phloem comes from analyses of exudates collected from the stylets of sap sucking insects or from incisions made to the vasculature. Among the legumes, members of the genus Lupinus exude phloem 'freely' from incisions made to the vasculature at most organs of the plant. This feature was exploited in this study to document some of the macromolecules present in exudate of L. albus and which might represent potential mobile signals. Phloem exudate was collected mainly from the sutures of developing pods and from inflorescence racemes. Two-dimensional polyacrylamide gel electrophoresis and tandem mass spectrometry were used to identify 83 proteins in exudate. Analysis of a cDNA library constructed from exudate identified 609 unique transcripts. Both proteins and mRNA were classified into functional groups. The largest group was related to general and energy metabolism, suggesting some metabolic activity probably to support the sieve element (SE). Other significant functional groups were represented by proteins and transcripts involved in protein synthesis, turnover and sorting, and in redox homeostasis. Proteins in these categories could play a role in maintaining the functions and stability of proteins in SE. Macromolecules involved in signalling such as transcripts encoding proteins mediating calcium levels and the Flowering locus T (FT) protein were also identified in phloem exudate of L. albus. FT protein has been recently identified as a mobile signal that induces flowering. ... The hen1 mutant accumulates low, sometimes even undetectable levels of miRNA due to the lack of methylation. No translocation of the five miRNA assayed under nutrient replete (non stress) conditions was observed. Translocation of miR395 in response to sulphur (S) deficiency was also investigated, and while conclusive evidence of translocation was not obtained, the data suggested some movement from roots to shoots (possibly in xylem) of a signal in response to S-deficiency. Future work is required to provide greater insight into the translocation path and identity of this S-deficiency signal. This study suggests that not all miRNA identified in phloem exudates are mobile, which raises the question about their biological relevance in SE and how they reached this location (e.g. through the action of a non-selective transport mechanism). However, there is also the possibility that miRNA are translocated only in response to specific internal or external cues not tested in this study. This is the first study that provides information on macromolecules present in the phloem exudate of a member of the Fabaceae. The information obtained from this work, provides a basis for future studies in the identification of potential mobile signals that may play a role in a communication network that traffics information around the plant, regulating its various developmental processes and responding to environmental cues.

Os sistemas de produção agrícola atuais são em sua maioria ecologicamente impactantes e utilizam altas quantidades de recursos naturais. Nesse contexto, a produção de hortaliças é uma atividade que se caracteriza pelo uso intensivo da terra com alta demanda por insumos e requer a adoção de estratégias de manejo com enfoque agroecológico de modo a sustentar sua produção. Dessa maneira, tendo em vista a crise ambiental na qual o planeta se insere, há a necessidade de se buscar formas sustentáveis de produção. Com o intuito de se avaliar a viabilidade de se aliar duas práticas utilizadas em sistemas de produção sustentáveis, o presente trabalho teve como objetivo estudar o efeito da consorciação de adubos verdes com alface quanto ao seu desempenho agronômico. Foi utilizado delineamento experimental de blocos ao acaso, com parcelas subdivididas, e seis repetições. Os tratamentos consistiram de alface consorciada em linha e em sistema de adição com os adubos verdes aveia-preta (Avena strigosa Schreb.), caupi [Vigna unguiculata (L.) Walp.] e tremoço-branco (Lupinus albus L.). Os adubos verdes foram semeados em 4 épocas distintas anteriormente ao transplante da hortaliça, sendo que estas épocas foram 60, 40, 20 e 0 dias. Os parâmetros avaliados para o desempenho de alface foram peso fresco de cabeça, peso seco de cabeça, diâmetro de cabeça, altura de cabeça, número de folhas por cabeça, peso fresco de raiz, peso seco de raiz, comprimento de raiz e altura do pendão floral. Foram também avaliados peso fresco e peso seco dos adubos verdes. Concluiu-se que a alface não-consorciada exibiu desempenho superior para a maioria dos parâmetros avaliados. As espécies adubos verdes, bem como sua época de semeadura em relação ao estabelecimento do consórcio influenciaram de maneiras diferentes o desempenho da hortaliça. Dentre os adubos verdes, o tremoço-branco resultou em melhor desempenho da alface consorciada em comparação com o caupi. O plantio simultâneo da alface e dos adubos verdes resultou nos melhores desempenhos da hortaliça, e a semeadura dos adubos verdes com 40 dias de antecedência do transplante da alface resultou em desempenhos inferiores para a maioria dos parâmetros. / The agricultural production systems currently used are in most cases ecologically impacting and use high amounts of natural resources. Within this context, vegetable production is an activity characterized by intensive land use and high demand for farm inputs, requiring the adoption of an agroecological management approach for sustaining its production. Thus, with the environmental crisis which the planet is in, it is necessary to search for healthy agriculture methods. With the purpose of evaluating the viability of joining two sustainable agriculture practices, the present work aimed at studying the effect of intercropping green manures with lettuce in its performance. A randomized complete blocks design, with six replicates was used. Treatments consisted of lettuce intercropped in rows in additive design with the green manures black oat (Avena strigosa Schreb.), cowpea [Vigna unguiculata (L.) Walp.] and white lupin (Lupinus albus L.). Intercropping was established in four different green manure sowing dates (60, 40, 20 and 0) prior to lettuce transplanting. Measurements in lettuce included fresh weight, dry weight, number of leaves, diameter of head, length of head, root fresh weight, root dry weight, root length and length of bolting plants. Measurements in green manures included fresh and dry weight. The monocropped lettuces had a better performance than the intercropped ones in most evaluated parameters. Green manure species and sowing date prior to lettuce transplant had different effects on the vegetable performance. Among the green manures, white lupin resulted in a better intercropped lettuce performance compared to cowpea. The simultaneous lettuce and green manures planting resulted in a better vegetable performance. When the green manures were sowed 40 days before lettuce transplanting the vegetable had its worst performance for most evaluated parameters.

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.