996 resultados para Sorghum bicolor (L.) Moench
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2016
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2016
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Due to the accelerating processes of soil salinization and shortage of fresh water, the practice of saline agriculture is gaining momentum in many areas of the world. However, there are some concerns that using saline water for irrigation may be non-environmentally sustainable, with potential to cause irreversible soil degradation. In addition, there is a lack of information on the morphological, physiological, and biochemical changes that can occur in plants when irrigated with saline water. In light of the above, the major aim of this work was to investigate the effects of a range of water salinity levels and irrigation regimes on the performances of salt tolerant species promising as future crop plants for saline agriculture. The following objectives were addressed: To determine the effects of different water regimes (leaching irrigation vs. no leaching irrigation) with water at increasing salinity concentrations on the growth, ion accumulation and water relations of Sorghum bicolor plants grown under saline soil conditions. To describe the germination response of Salicornia europaea seeds across a wide range of water salinity levels through six reliable indices for screening salinity tolerance at the seed germination stage. To explore the different physiological responses of six wild halophytes commonly found in the Mediterranean area (Artemisia absinthium, Artemisia vulgaris, Atriplex halimus, Chenopodium album, Salsola komarovii, and Sanguisorba minor), and rank their tolerance after exposure to growing levels of water salinity. To identify the main adaptation mechanisms that distinguish C3 from C4 halophytes when exposed to increasing salinity in the growth media, through a comparative study between the C3 species Atriplex hortensis and the C4 species Atriplex halimus. To identify the main adaptation mechanisms that distinguish annual from perennial halophytes when exposed to severe conditions of salinity and drought, through a comparative analysis between two annual Salicornia spp. and the perennial Sarcocornia fruticosa.
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A propsito de la dispersin de Verbascum boerhavii var. bicolor (Bad.) Arcang. en Catalunya. Verbascum boerhavii L. var. bicolor (Bad.) Arcang., Comp. Fl. Ital. 505 (1882). = V. bicolor Bad., Osserv., 3 (1824) = V. boerhavii L. fma. bicolor (Bad.) Murb., Lunds. Univ. Arssk, 29 (2): 159 (1933). = V. maiale DC. var. bicolor (Bad.) Rouy, Fl. Fr. 9:9 (1909).
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Cotyledon mesophyll cell morphology and lipid and protein synthesis of T. grandiflorum, T. subincanum and T. bicolor were analyzed and compared with T. cacao. These species possess foliar cotyledons folded around the hypocotyl radicle axis, typical of Sterculiaceae. Fruit size, morphology and weight are very distinct amongst the four species and so are the respective seeds. The main axis of the T. grandiflorum and T. bicolor seeds measured about 30 mm, while T. subincanum and T. cacao seeds measured 17 mm and 26 mm respectively. The seed weights of T. grandiflorum, T. bicolor, T. subincanum and T. cacao were 11.6 g, 9.4 g, 2.1 g and 3.0 g, respectively. The cotyledon mesophylls of the four species contained mainly polysaccharides and lipid-protein reserve cells. Theobroma cacao, T. grandiflorum and T. subincanum were composed of greater than 50% lipids. For the four species, lipid globules gradually accumulated adjacent to the cell wall, and these globules measured from 1 to 3 m. TEM showed low-density proteins inside the central vacuole of the young mesophyll cells of T. cacao. The protein reserves of the mature cells were densely scattered amongst the lipid bodies, and a few starch granules occurred together with the cotyledon mesophyll of the four species. Polyphenolic cells were found throughout the mesophyll cells or aligned with the respective vascular bundles. Immature cells demonstrated the capacity to synthesize all these reserves, but gradually the pre-determined cells produced mainly lipid-protein reserves. Besides the unique characteristics of the T. cacao products, the lipid-protein synthesis capacities of T. grandiflorum, T. subincanum and T. bicolor suggest various possibilities for new industrialized food, pharmaceutical and cosmetic products.
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Conselho Nacional de Desenvolvimento Cientfico e Tecnolgico (CNPq)
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Comparative genetic maps of Papuan Saccharum officinarum L. (2n = 80) and S. robustum (2n = 80) were constructed by using single-dose DNA markers (SDMs). SDM-framework maps of S. officinarum and S. robustum were compared with genetic maps of sorghum and maize by way of anchor restriction fragment length polymorphism probes. The resulting comparisons showed striking colinearity between the sorghum and Saccharum genomes. There were no differences in marker order between S. officinarum and sorghum. Furthermore, there were no alterations in SDM order between S. officinarum and S. robustum. The S. officinarum and S. robustum maps also were compared with the map of the polysomic octoploid S. spontaneum SES 208 (2n = 64, x = 8), thus permitting relations to homology groups (chromosomes) of S. spontaneum to be studied. Investigation of transmission genetics in S. officinarum and S. robustum confirmed preliminary results that showed incomplete polysomy in these species. Because of incomplete polysomy, multiple-dose markers could not be mapped for lack of a genetic model for their segregation. To coalesce S. officinarum and S. robustum linkage groups into homology groups (composed of homologous pairing partners), they were compared with sorghum (2n = 20), which functioned as a synthetic diploid. Groupings suggested by comparative mapping were found to be highly concordant with groupings based on highly polymorphic restriction fragment length polymorphism probes detecting multiple SDMs. The resulting comparative maps serve as bridges to allow information from one Andropogoneae to be used by another, for breeding, ecology, evolution, and molecular biology.
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Les changements environnementaux actuels entrainent des modifications importantes dans les pressions de slection qui agissent sur les populations naturelles. Cependant, la capacit de rponse des populations ces modifications et limportance relative des diffrents mcanismes comme la plasticit phnotypique et les changements de la composition gntique des populations restent encore trop peu connus. Lobjectif gnral de ma thse tait donc dvaluer les rles de la plasticit phnotypique et de la variation gntique sur le potentiel volutif en population naturelle. Pour ce faire, jai utilis comme modle dtude lHirondelle bicolore (Tachycineta bicolor), un passereau migrateur qui est suivi dans le Sud du Qubec depuis 2004 dans un environnement htrogne. Dans un premier temps (chapitre 2), jai valu les dterminants environnementaux de la date de ponte et valu leurs effets des niveaux individuels et populationnels de plasticit phnotypique. Comme observ chez de nombreuses espces aviaires, la temprature avait un effet important sur la synchronisation de la ponte, similaire au niveau individuel et populationnel, avec les dates de ponte plus htive lorsque les tempratures taient plus chaudes. Par contre, ces relations semblaient contraintes par la densit locale dhirondelles, considre dans ce systme dtude comme un indice de la qualit de lenvironnement. Plus prcisment, les rponses plastiques la temprature taient moins prononces faible densit, cest--dire dans les habitats plus contraignants. Ces rsultats suggrent donc que malgr la prsence de plasticit phnotypique chez une espce donne, son efficacit pour pallier les changements climatiques peut tre ingale entre les populations. Dans un deuxime temps (chapitre 3), je me suis intresse 4 gnes candidats lis la phnologie (CLOCK, NPAS2, ADCYAP1 et CREB1) montrant de la variation de type courtes rptitions en tandem, et leur relation avec deux traits phnologiques, la date de ponte et le temps dincubation. Ces analyses ont montr plusieurs relations entre la variation observe ces gnes et celle des traits phnologiques tudis, dans la plupart des cas en interaction avec des variables environnementales (densit locale, latitude ou temprature printanire). Par exemple, les femelles avec en moyenne des allles plus courts au gne CLOCK pondaient plus tt que celles avec des allles plus longs, une relation plus marque densit locale leve. Les diffrents rsultats suggrent limportance que peuvent prendre les interactions gnotype-environnement, qui sont rarement prises en compte dans les tudes de gnes candidats, et qui pourraient expliquer une partie des rsultats discordants entre les celles-ci. Dans un troisime temps (chapitre 4), jai vrifi la faisabilit dune tude en gntique quantitative avec les donnes rcoltes dans le systme dtude utilise, caractris par un fort taux de reproduction hors couple et un faible recrutement des oisillons. Plus prcisment, jai test laide de donnes empiriques et simules la prcision et lexactitude des estimations dhritabilit et de corrlations gntiques pour trois types de traits, morphologiques, reproducteurs et doisillons. Les rsultats suggraient un manque de prcision important pour les traits morphologiques et reproducteurs, de mme que des biais considrables lors de lutilisation du pdigre social plutt que du pdigre gntique. Ces analyses rvlent entre autres lutilit des simulations pour tester adquatement la faisabilit dune tude en gntique quantitative sur une population donne. Dans une dernire tude (chapitre 5), jai document les effets de lhtrognit environnementale et de lutilisation de diffrentes approches de gntique quantitative sur les prdictions de rponses volutives en population naturelle. Plus particulirement, cette tude sest concentre sur trois traits morphologiques (masse, longueur de laile et du tarse) mesurs diffrents moments au cours du dveloppement des oisillons. Les diffrentes analyses ont montr une slection plus forte faible densit locale pour la masse 12 jours ainsi que des variations dans les composantes de variances phnotypiques selon la qualit de lenvironnement (densit locale faible ou leve) pour la plupart des combinaisons trait-ge tudies. Il en rsultait une tendance des rponses volutives prdites plus grandes faible densit locale. Par contre, les prdictions obtenues avec lquation du reproducteur et le second thorme de la slection diffraient frquemment, et contrastaient grandement avec les tendances phnotypiques observes. En somme, les rsultats de ma thse suggrent que les possibilits dajustement aux changements environnementaux par la plasticit phnotypique et dadaptation par des changements gntiques entre les gnrations peuvent varier selon lenvironnement expriment par une population. Mes recherches contribuent une meilleure comprhension des facteurs et mcanismes influenant la persistance long terme des populations naturelles face aux modifications dans les pressions de slection.
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Groundnut shell (GS), after separation of pod, is readily available as a potential feedstock for production of fermentable sugars. The substrate was delignified with sodium sulfite. The delignified substrate released 670 mg/g of sugars after enzymatic hydrolysis (50 degrees C, 120 rpm, 50 hrs) using commercial cellulases (Dyadic Xylanase PLUS, Dyadic Inc. USA). The groundnut shell enzymatic hydrolysate (45.6 g/L reducing sugars) was fermented for ethanol production with free and sorghum stalks immobilized cells of Pichia stipitis NCIM 3498 under submerged cultivation conditions. Immobilization of yeast cells on sorghum stalks were confirmed by scanning electron microscopy (SEM). A maximum of ethanol production (17.83 g/L, yield 0.44 g/g and 20.45 g/L, yield 0.47 g/g) was observed with free and immobilized cells of P. stipitis respectively in batch fermentation conditions. Recycling of immobilized cells showed a stable ethanol production (20.45 g/L, yield 0.47 g/g) up to 5 batches followed by a gradual downfall in subsequent cycles.
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We evaluated the ratio between the number of pollen foragers and the total number of bees entering colonies of Melipona bicolor, a facultative polygynous species of stingless bees. The variables considered in our analysis were: seasonality, colony size and the number of physogastric queens in each colony. The pollen forager ratios varied significantly between seasons; the ratio was higher in winter than in summer. However, colony size and number of queens per colony had no significant effect. We conclude that seasonal differences in pollen harvest are related to the production of sexuals and to the number of individuals and their body size.
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Correct modeling of root water uptake partitioning over depth is an important issue in hydrological and crop growth models. Recently a physically based model to describe root water uptake was developed at single root scale and upscaled to the root system scale considering a homogeneous distribution of roots per soil layer. Root water uptake partitioning is calculated over soil layers or compartments as a function of respective soil hydraulic conditions, specifically the soil matric flux potential, root characteristics and a root system efficiency factor to compensate for within-layer root system heterogeneities. The performance of this model was tested in an experiment performed in two-compartment split-pot lysimeters with sorghum plants. The compartments were submitted to different irrigation cycles resulting in contrasting water contents over time. The root system efficiency factor was determined to be about 0.05. Release of water from roots to soil was predicted and observed on several occasions during the experiment; however, model predictions suggested root water release to occur more often and at a higher rate than observed. This may be due to not considering internal root system resistances, thus overestimating the ease with which roots can act as conductors of water. Excluding these erroneous predictions from the dataset, statistical indices show model performance to be of good quality.
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Multi-environment trials (METs) used to evaluate breeding lines vary in the number of years that they sample. We used a cropping systems model to simulate the target population of environments (TPE) for 6 locations over 108 years for 54 'near-isolines' of sorghum in north-eastern Australia. For a single reference genotype, each of 547 trials was clustered into 1 of 3 'drought environment types' (DETs) based on a seasonal water stress index. Within sequential METs of 2 years duration, the frequencies of these drought patterns often differed substantially from those derived for the entire TPE. This was reflected in variation in the mean yield of the reference genotype. For the TPE and for 2-year METs, restricted maximum likelihood methods were used to estimate components of genotypic and genotype by environment variance. These also varied substantially, although not in direct correlation with frequency of occurrence of different DETs over a 2-year period. Combined analysis over different numbers of seasons demonstrated the expected improvement in the correlation between MET estimates of genotype performance and the overall genotype averages as the number of seasons in the MET was increased.
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O presente trabalho foi realizado com o fito de estabelecer uma seleo prvia entre 32 variedaeds de soja (Glycine max. (L.) Merril), com base nas anlises bromatolgicas das sementes. Foram determinados teores de umidade (U), cinzas (RM), protena bruta (PB), gordura bruta ou extrato etreo (EE), fibra bruta (F) e extrativo no nitrogenado (ENN). As anlises da varincia permitem tirar as seguintes concluses: 1) Entre as variedades classificadas no grupo forrageiro e comestvel, tem-se: Mandarin 8a (40,16% PB), Bicolor de Calai (39,64% PB) e Aliana (38,70% PB). 2) De acordo com a classificao estabelecida, para o grupo produtor de leo, as variedades Lee, Hood, Lincoln (Blanco) Improved Pelican (2), Lincoln (Morado) e Improved Pelican (1), se destacam com 21,76, 21,65, 21,62, 21,35, 21,13 e 21,04% de EE respectivamente. 3) As variedades que apresentaram menor percentagem de fibra so: Hernnjn.0 107, Hood, Mogiana, Hill e Selection n. 135, com 9,59; 9,62; 9,68; 10,02 e 10,12% F respectivamente. 4) Encontrou-se uma correlao positiva entre o teor de protena bruta e o de cinzas.
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Mycorrhizal symbioses--the union of roots and soil fungi--are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants. Boreal, temperate and montane forests all depend on ectomycorrhizae. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains approximately 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and nitrogen cycles that are fundamental to sustainable plant productivity.
