, ELIEMAR CAMPOSTRINI 5 RESUMO-Foram otimizados os protocolos de micropropagação das cultivares de abacaxizeiro 'Vitória' e 'IAC Fantástico', bem como as respostas fotossintéticas e de crescimento destes genótipos à alteração do ambiente de cultivo in vitro. Para as duas cultivares, os tratamentos foram dispostos em DIC, com seis repetições e cinco plantas por repetição, em um esquema de parcelas subsubdivididas, constituídas de qualidade de luz (branca e vermelha), tipo de frasco de cultivo (fechado e ventilado) e concentração de sacarose no meio de cultivo (15 e 30 g L -1 ). A avaliação foi feita após 40 dias de cultivo in vitro. Nas condições deste estudo, não houve assimilação fotossintética do carbono. Essa não assimilação foi associada ao comprometimento bioquímico e sem comprometimento na eficiência fotoquímica. A presença da sacarose pode ser considerada o fator responsável pela não assimilação do CO 2 . Em comparação à cv. IAC Fantástico, a cv. Vitória apresentou maior crescimento devido à maior absorção de carbono via sacarose adicionada ao meio de cultivo. Termos para Indexação: 'Vitória', 'IAC Fantástico', micropropagação, Ananas comosus, ventilação. PHOTOSyNTHETIC EFFICIENCy AND GENOTyPES GROwTH OF PINEAPPLE CULTIVATED IN VITRO IN DIFFERENT QUALITIES OF LIGHT, GROwING JAR TyPES AND CONCENTRATION OF SUCROSEABSTRACT -Protocols for the micropropagation of pineapple cv. Vitória and cv. IAC Fantástico were optimized, as well as the photosynthetic and growth responses of these genotypes in response to changing the in vitro environment. For the two cultivars, treatments were arranged in a completely randomized design, with six repetitions and five plants per repetition, in a sub plots subdivided, made up of light qualities (white and red), types of culture vessels (closed and ventilated) and sucrose concentrations in the growth medium (15 and 30 g L -1). The evaluation was made after 40 days of in vitro culture. Under the conditions of this study there was no photosynthetic carbon assimilation. This non-assimilation was associated with biochemical compromises rather than photochemical efficiency. The presence of sucrose should be the factor responsible for non-CO 2 assimilation. The cv. Vitória showed higher growth than the cv. IAC Fantástico due to the higher carbon absorption via sucrose.

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Sugarcane (Saccharum officinarum L.) is an effective crop for biomass production and is used mainly for sugar production and bio-fuel. Irrigation water has become less available in many regions due to global climate change and domestic. To confront the challenge of water utilization, there is a need to develop water-saving irrigation techniques in order to maximize crop water use efficiency. Partial rootzone drying (PRD) is a water-saving irrigation strategy that involves irrigating only part of the rootzone while leaving the other portion to dry to a predetermined level before the next irrigation. The objective of this study was to examine whether PRD affects photosynthetic capacity and growth in young sugarcane plants (48-day old). The experiment was conducted from January to April, 2011 in a greenhouse. Sugarcane mini-stalks were transplanted with divided root systems at 20 days of age into two pots. The pots were filled with soil (oxisol), sand and manure (1:1:1). The sugarcane plants were wellwatered in the first 10 days after transplanting. Thereafter, the plants were exposed to three irrigation regimes: (1) Full irrigation (FI) (control); in which both soil compartments were watered to 100 % field capacity; (2) PRD; in which one soil compartment was watered to the field capacity while the other was allowed to dry for 17 days, then the plants were reirrigated; (3) no irrigation (NI); in which both compartments were allowed to dry for 17 days, then reirrigated. Net photosynthetic rate, stomatal conductance, transpiration, predawn leaf water potential, leaf area, shoot dry weight, root dry weight, root volume, and intrinsic water use efficiency were measured. PRD did not significantly reduce growth and gas exchange in comparison to FI, yet there was a 17.6 % reduction in water application. In addition, the agronomic water use efficiency was higher in PRD (4.1 g l -1 ) and FI (3.6 g l -1 ) than NI (2.9 g l -1 ). In this study, PRD irrigation reduced water consumption by 17.6 % with a total biomass reduction of 11.3 % as compared with fully watered plants. In conclusion, PRD may be an efficient irrigation strategy and promising for application in drought-prone regions for saving water where sugarcane is produced.

Resíduos da agroindústria como substrato na aclimatização de mudas micropropagadas de bromélia RESUMO Resíduos da agroindústria tais como, casca do fruto da mamoneira decomposta e fibra de coco aparecem como materiais promissores para uso como substrato, devido às grandes quantidades que são geradas e acumuladas. Estes podem ser utilizados puramente, em frações de misturas entre si ou com outros materiais. O objetivo deste trabalho foi avaliar o uso de casca do fruto da mamoneira e fibra de coco como substrato na aclimatização de mudas micropropagadas de bromélia (Aechmea pineliana (Brongniart ex Planchon) Baker), de interesse conservacionista. Os tratamentos foram constituídos por oito diferentes composições de substratos: casca do fruto da mamoneira passada em peneira de granulometria cinco milímetros (mm) (CFM5) e 10 mm (CFM10); Plantmax HT ® (SC); fibra de coco (FC) + CFM5; FC + CFM10; FC + SC; CFM5 + SC e CFM10 + SC. Os resultados dos substratos casca do fruto da mamoneira e fibra de coco são estatisticamente iguais ou superiores aos obtidos com o substrato comercial, portanto podem ser utilizados para aclimatizar mudas de A. pineliana. Palavras-chave: Aechmea pineliana, casca do fruto da mamoneira, fibra de coco Agroindustry residues as substrate on micropropagated bromeliad plantlet acclimatization ABSTRACT Agroindustry residues such as decomposed castor bean fruit husks and coconut fiber appear as promising materials for use as substrate, due to the large amounts that are generated and accumulated. These can be used separately, mixed, or in mixture with other materials. The objective of this study was to evaluate the use of castor bean fruit husks and coconut fiber as substrate in the acclimatization of plantlets of bromeliad (Aechmea pineliana (Brongniart ex Planchon) Baker), of conservation interest. The treatments consisted of eight different substrate compositions: castor bean fruit husks sieve graded with sieve opening size five millimeters (mm) (CFM5), and 10 mm (CFM10), Plantmax HT ® (SC); coconut fiber (FC) + CFM5; FC + CFM10; FC + SC; CFM5 + SC and CFM10 + SC. The castor bean fruit husk and coconut fiber substrates show results equal to or better than those obtained with the commercial substrates, and therefore may be used for acclimatizing A. pineliana plantlets.