How multicellular organisms develop from a single-celled fertilized egg or zygote that in no way resembles the adult form is one of the major challenges in biology The phase of rapid cell division that follows fertilization produces individual units from which the basic body plan of the adult organism is to be constructed Elaboration of functional organs and tissues from their primordia involves

The gluing properties of plantation-grown gmelina wood (Gmelina arborea Roxb.) from Nigeria were investigated. Three wood peeling temperatures - 20°C, 50°C and 85°C; two glue types - urea-formaldehyde (UF) and phenol-formaldehyde (PF); two glue spreads - 25 kg/MDGL (55 lb) and 32 kg/MDGL (70 lb); and two closed assembly times - 10 minutes and 20 minutes were used. Veneers from the sample logs were peeled tight and were 1.27 mm (0.05 in) thick. The specific gravity for the logs was determined and its influence on the probable end uses of gmelina plywood discussed. Three 5-ply plywood panels were made, for each treatment combination for 72 in all. A total of 1438 shear test specimens were used. The UF specimens were tested dry and after vacuum-pressure treatment whereas the PF specimens received vacuum-pressure and boil-dry-boil tests. Bond quality was evaluated on the basis of wood shear strength and percentage wood failure. Results were compared to the U.S., British and German Plywood Standards. Wood peeling temperature was highly significant regardless of glue type and bond quality testing method. Heating of gmelina logs prior to peeling did not improve veneer peel-quality. Veneers were of the highest peel-quality (basis: Thickness variation and surface roughness) when logs were peeled at 20°C. The highest peeling temperature yielded the lowest peel-quality. Bond quality, (percentage wood failure), was consistently reduced by increasing peeling temperature and was lowest at 85°C in all the UF and PF treatments, regardless of bond quality testing method. Ignoring glue spreads, panels made from veneers cut at temperatures of 50°C and 85°C gave the highest shear strength values among the UF treatments. On the other hand, panels from veneers cut at temperatures of 20°C and 85°C gave the highest shear strength values among the PF treatments. All factors considered, treatment combination of Spread 55 - Time 20, arising from veneers cut at the control temperature of 20°C, gave an impressive bond quality in all the UF and PF treatments used. Five of the 12 PF treatments used, regardless of type of bond quality testing method, pass the U.S. Plywood Standard; one passes the British Standard; while all pass the German Standard. On the other hand, five of the 12 UF treatments from vacuum-pressure test pass the U.S. Standard; two pass the British Standard; while all pass the German Standard. Furthermore, all the 12 UF treatments from dry test pass the U.S. Standard; six pass the British Standard; while all pass the German Standard. From the results obtained, plantation-grown Gmelina arborea wood from Nigeria, with a specific gravity of 0.41 ± 0.027 (as determined), was found suitable for use as construction plywood, core and crossband veneer for decorative panel as well as container veneer and plywood. The dominant factor accounting for the general trend of low percentage wood failure was attributed to veneer surface inactivation, resulting from surface aging of veneers. / Forestry, Faculty of / Graduate

Contexte et objectifs : Les tentatives pour expliquer les variations des paramètres foliaires fondées uniquement sur les facteurs environnementaux, ce qui conduira à des erreurs importantes si la plante montre des variations ontogénétiques substantielles des propriétés foliaires. Nous avons évalué les variations des 27 traits morpho-anatomiques des feuilles de Dipterocarpus alatus durant six stades de développement architectural et entre les axes à un stade de développement donné sous deux conditions lumineuses différentes.Méthodologies:Une analyse architecturale a été réalisée pour distinguer précisément et objectivement des catégories d'axes et stades de développement de Dipterocarpus alatus. Les feuilles ont été collectées sur l'unité de croissance plus récente et complète sur la partie supérieure du tronc et sur la partie plus externe de la branche du milieu couronne des arbres qui poussent sous deux différentes conditions lumineuses. Vingt-deux traits foliaires ont été mesurées et calculées sur des images de tracés feuilles et de sections transversaux à l'aide de logiciel ImageJ. Densité stomatal a été calculée sur l'impression de vernis à ongles de la surface inférieure des feuilles. Quatre traits de chlorophylle ont été déterminées. Les tests d'ANOVA et Tukey ont été utilisés pour déterminer les différences entre les stades de développement et des axes. La contribution relative lmg a été calculée avec package R relaimpo et comparées avec l'analyse bootstrap pour déterminer le stade ontogénétique, catégorie axe ou l'intensité lumineuse, ce qui est expliqué plus les variations de l'anatomie des feuilles.Résultats:La morphologie et l'anatomie des feuilles diffère fortement durant l'ontogenèse pour les quatre axes en terme d'ordre et de catégorie deux sous des conditions lumineuses. L'effet de l'axe a été présentée au stade B, C, D et F, mais ont tendance à être insignifiante au stade E. Ontogenèse de l'arbre expliqué plus de variations dans la morphologie des feuilles et de l'anatomie que l'intensité lumineuse. Catégorie d'axe expliqué plus de variations dans la morphologie des feuilles, mais pas dans l'anatomie des feuilles que l'ontogenèse de l'arbre. Conclusions:Fortes et significatives variations intra-spécifiques (pendant l'ontogenèse et entre axes) peuvent influencer les variations inter-spécifiques, et donc contestent la validité de la valeur moyenne des traits foliaires entre les espèces. Ontogenèse de l'arbre contribué plus que l'intensité de la lumière dans l'explication de la variabilité dans la morphologie et l'anatomie des feuilles à la fois sur le tronc et deuxième l'ordre l'axe recommande fortement que les études sur les réponses de la morphologie et l'anatomie des feuilles à l'environnement doivent corriger l'effet de l'ontogenèse. / Background and Aims:Attempts to explain variations in leaf parameters based solely on environmental factors, this will lead to significant errors if the plant shows substantial ontogenetic variations in leaf properties. We evaluated variations in 27 morpho-anatomical leaf traits of Dipterocarpus alatus over six architectural development stages and between axes at a given development stage under two different light conditions. Methods:An architectural analysis was conducted to distinguish precisely and objectively axis categories and developmental stages of Dipterocarpus alatus. Leaves were collected on the most recent complete growth unit on the top of the trunk and the outermost part of the middle-crown branch with branchlet and twig from trees growing under two different light conditions. Twenty two leaf traits were measured and calculated using ImageJ on images of leaf tracings and cross-sections. Stomatal density was calculated on nail varnish impression of the leaf lower surface. Four chlorophyll traits were determined. One-way ANOVA and Tukey post-hoc tests were used to determine differences between development stages and axes. The lmg relative contribution was calculated with R package relaimpo and compared with bootstrap analysis to determine ontogenetic stage, axis category or light intensity, which explained more the variations in leaf anatomy.Key results:Leaf morphology and anatomy differed strongly during ontogeny for all four axes in term of order and category under both light conditions. The axis effect was displayed at stages B, C, D and F but tend to be insignificant at stage E. Tree ontogeny explained more variations in leaf morphology and anatomy than light intensity. Axis category explained more variations in leaf morphology but not in leaf anatomy than tree ontogeny. Conclusions: Strong and significant intraspecific variations (during ontogeny and between axes) may influence the interspecific variations, and thus challenge the validity of the mean value of leaf traits between species. Tree ontogeny contributed more than light intensity in explanation of the variability in leaf morphology and anatomy both on the trunk and second axis order strongly recommends that studies on the responses of leaf anatomy to the environment need to correct for the ontogeny effect.

Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-01-23T10:47:55Z No. of bitstreams: 1 DissACCA.pdf: 1129010 bytes, checksum: b80861cac806c1b3baecbc65e887e809 (MD5) / Approved for entry into archive by Camila Passos (camilapassos@ufscar.br) on 2017-01-23T15:47:26Z (GMT) No. of bitstreams: 1 DissACCA.pdf: 1129010 bytes, checksum: b80861cac806c1b3baecbc65e887e809 (MD5) / Approved for entry into archive by Camila Passos (camilapassos@ufscar.br) on 2017-01-23T15:47:35Z (GMT) No. of bitstreams: 1 DissACCA.pdf: 1129010 bytes, checksum: b80861cac806c1b3baecbc65e887e809 (MD5) / Made available in DSpace on 2017-01-23T15:47:48Z (GMT). No. of bitstreams: 1 DissACCA.pdf: 1129010 bytes, checksum: b80861cac806c1b3baecbc65e887e809 (MD5) Previous issue date: 2016-06-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Maize can be intercropped with green manures, which in addition to performing the coverage and soil protection, the weeds control, also cycle nutrients and perform nitrogen biological fixation. This study aimed at evaluating the growth, yield of grains and straw, the content of macronutrients of maize and the weeds control in intercropping with perennial green manures sown at two different maize growth stages. The experiment was conducted in the agricultural year of 2014/2015, at UFSCar/Araras-SP, in randomized complete blocks in factorial scheme 3 x 2 + 1 with 4 repetitions. The factors were: 3 species of green manures (calopogonio (Calopogonium mucunoides Desv.); kudzu (Pueraria phaseoloides (Roxb) Benth.) and perennial soybean (Neonotonia wightii (Wight & Arn) Lackey.) and two green manures sowing times (sowing at the V4 - four expanded leaves and VT – bolting of maize). And a control treatment, maize monoculture. The evaluations were: in the R1/R2 of maize stage - milky/doughy grain (height (ALT); diameter (DIA); specific leaf area (AFE); leaf area index (IAF); stalk dry matter (MSC), leaves (MSF) and total (MST) of maize; Falker chlorophyll index (ICF); number of leaves above the upper ear (FAS)); in the R5 of maize stage – chalky grain (dry mass of green manure (MSA); total dry mass maize intercropping/green manure (MSTC); percentage of land cover (PC) and dry mass of weeds (MSE)); in the R6 – maize harvest (final plant stand (EST); prolificacy (PROL); number of rows per ear (NFE); number of kernels per row (NGF); yield of grain (PROD); weight of 100 grains (P100) and content of macronutrients of maize). It was found higher production of EF with the sowing of green manures in the V4 stage (69,814 plants ha-1), being the intercropping maize/calopogonio with higher values of MSA and PC, with 1002.00 kg ha-1 and 35.63%, respectively. The highest P100 occurred in the VT (32.89 g). There was not difference for the other variables. The PROD was 9.04 t ha-1 and 7.0 t ha-1 of MSTC. The smallest leaf N content was observed in the intercropping with calopogonio in V4 (22.75 g kg-1). The Ca had smallest levels for the perennial soybean in the VT and kudzu in the V4. The smallest Mg content was in intercropping with the soybean perennial in the VT, in the P was in the intercropping with calopogonio and S, when the sowing of the green manures occurred in V4 of maize. For K, there was not statistical difference. The MSTC production was not affected by green manures, with maize straw production in monoculture and in the intercropping systems exceeding the minimum amount recommended for ground cover (6.0 t ha-1). The green manures negatively affect the content of P, K, Ca, Mg and S in maize and calopogonio sown in the VT, the kudzu and the soybean perennial sowing in the V4 and VT, contributed to provide N to maize. / O milho pode ser consorciado com adubos verdes perenes, que além de realizarem a cobertura e proteção do solo, o controle de espontâneas, ciclam nutrientes e realizam a fixação biológica de nitrogênio. Objetivou-se com este trabalho avaliar o crescimento, a produtividade de grãos e de palhada, o teor de macronutrientes do milho e a supressão das plantas espontâneas em cultivo consorciado com adubos verdes perenes semeados em duas épocas distintas de desenvolvimento do milho. O experimento foi realizado na safra de 2014/2015, na UFSCar/Araras-SP, em blocos casualizados no esquema fatorial 3 x 2 + 1 com 4 repetições. Os fatores foram: 3 espécies de adubos verdes perenes (calopogônio (Calopogonium mucunoides Desv.); puerária (Pueraria phaseoloides (Roxb) Benth.) e soja-perene (Neonotonia wightii (Wight & Arn.) Lackey) e 2 épocas de semeadura (semeadura no V4 – quatro folhas expandidas e VT – pendoamento do milho). E a testemunha, o milho solteiro. Avaliaram-se: no estádio R1/R2 do milho - grão leitoso (altura (ALT), diâmetro (DIA), área foliar específica (AFE), índice de área foliar (IAF), massa de matéria seca do colmo (MSC), folhas (MSF) e total (MST) do milho, índice de clorofila Falker (ICF) e nº de folhas acima da espiga superior (FAE)); no estádio R5 do milho – grão farináceo (massa de matéria seca dos adubos verdes (MSA), massa de matéria seca total do consórcio milho/adubos verdes (MSTC), porcentagem de cobertura do solo (PC) e massa de matéria seca das plantas espontâneas (MSE)); no estádio R6 – colheita do milho (estande final de plantas de milho (EF), prolificidade (PROL), número de fileiras por espiga (NFE), número de grãos por fileira (NGF), produtividade de grãos (PROD), peso médio de 100 grãos (P100) e o teor de macronutrientes no milho). Foi encontrado maior EF com a semeadura dos adubos verdes no V4 (69.814 plantas ha-1), sendo o consórcio milho/calopogônio com maiores valores de MSA e PC, com 1002,0 kg ha-1 e 35,63%, respectivamente. O maior P100 ocorreu no VT (32,89 g). Não houve diferença para as outras variáveis. A PROD foi de 9,04 t ha-1 e 7,0 t ha-1 de MSTC. O menor teor de N foliar do milho foi observado no consórcio com calopogônio no V4 (22,75 g kg-1). O Ca teve menores teores para a soja perene no VT e a puerária no V4. O menor teor de Mg foi no consórcio com a soja perene semeada no VT, de P foi no consórcio com calopogônio e de S, ocorreu quando a semeadura dos adubos verdes ocorreu no V4 do milho. Para o K, não houve diferença estatística. A produção de MSTC não foi influenciada pelos adubos verdes, com a produção de palha do milho em cultivo solteiro e nos sistemas consorciados superior a quantidade mínima recomendada para cobertura do solo (6,0 t ha-1). Os adubos verdes afetaram de forma negativa o teores foliares de P, K, Ca, Mg e S do milho e o calopogônio semeado no VT, a puerária e a soja perene semeados no V4 e VT, contribuíram para o incremento de N ao milho.