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Pineapple is one of the most important fruits, with large production in tropical and subtropical regions and great appreciation by consumers all over the world. The pineapple plant has many specific morphological, anatomical and physiological characteristics that determine crucial aspects of pineapple crop management, such as flower induction, water use and vegetative methods of propagation. The use of sexual reproduction of pineapple is restricted to breeding purposes carried out by research institutes looking for new hybrids with improved agronomic characteristics. Seeds are only produced if cross pollination among varieties occurs. Commercially pineapple has to be propagated by vegetative material, an asexual reproduction, without new combinations of genes. Some types of propagules are naturally produced by the plants and called conventional planting material. Its availability and quality depend on many factors, especially cultivar and environment. Management techniques of this material have been continuously developed and will be addressed. In addition to the conventional planting material, which in many situations is not sufficient to assure expansion or at least maintenance of the cultivated area, several other methods of vegetative propagation of pineapple have been studied and made available along the last decades and will also be discussed, involving techniques of stem sectioning, apical growing point gouging and chemical treatment for transformation of flowers into plantlets. Stem sectioning has been especially interesting, as it is mostly done using plant residues available at low cost, and is a rather simple method suited for multiplication and production of disease-free planting material in nurseries. Gouging and chemical treatment are less practiced, but can be applied in ratoon crops, thereby avoiding the loss of the first cycle fruit. Chemical treatment usually results in rather small plantlets, that must be further grown in nurseries before planting them in the field. And finally micropropagation will also be focused, as in vitro production of plantlets is a very important method of multiplication of new pineapple varieties, but this method yet has not been transformed into a common commercial way of pineapple propagation due to the final high cost and to the still high risks of incidence of somaclonal variations among the plantlets produced.

Efeito da sacarose e do sorbitol na conservação in vitro de segmentos nodais de mangabeira Resumo -A mangabeira (Hancornia speciosa Gomes) é uma espécie cujas regiões de ocorrência natural vêm sofrendo grande pressão antrópica, a qual está provocando erosão genética em muitas populações nativas, principalmente da região Nordeste. Em virtude da existência de poucas coleções de mangabeira conservadas ex situ, evidencia-se a importância do desenvolvimento de um método alternativo e complementar para a conservação de germoplasma dessa espécie. Este trabalho teve como objetivo o aprimoramento técnico-científico da conservação in vitro por crescimento lento de mangabeira. Para avaliar o efeito da sacarose e sorbitol segmentos nodais foram inoculados em tubos de ensaio com 25 mL de meio de cultura MS suplementado com 1 mg L -1 de ácido indolacético e 1 mg L -1 de benzilaminopurina e diferentes concentrações de sorbitol (10; 20 e 40 g L -1 ), combinadas com 0 e 15 g L -1 de sacarose. Na etapa de recuperação do crescimento, explantes conservados in vitro por 120 dias no experimento anterior foram inoculados em meio de cultura MS sendo a viabilidade das culturas avaliadas aos 30 e 60 dias. A conservação in vitro de segmentos nodais de mangabeira na ausência de sacarose e na presença de 10 ou 20 g L -1 de sorbitol é viável sob condições de crescimento lento por 120 dias. Explantes mantidos na ausência de sacarose ou na presença de 10 g L -1de sorbitol na fase de conservação apresentam maior viabilidade na retomada do crescimento até os 60 dias de cultivo.Palavras chave -Hancornia speciosa Gomes. Crescimento lento. Reguladores osmóticos.

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