brassinosteróide e substratos na aclimatização do abacaxizeiro ‘Imperial’

Abstract

Brassinosteroid and substrates in acclimatization of 'Imperial' pineapple. This work aimed to evaluate the effects of different concentrations of a brassinoesteroid analogue (BIOBRAS-16) and two substrates on the growth of micropropagated seedlings of 'Imperial' pineapple. A randomized block design was used in a 2 x 5 x 4 factorial scheme, evaluating five concentrations of BIOBRAS-16 (0; 0.1; 0.3; 0.5 and 1 mg L-1), two types of substrates and four sampling periods (60, 90, 120 and 150 days after planting). The substrates used were Plantmax ® and another obtained from a mix of composting sugar-cane bagasse and filter cake (CC). The seedlings were transplanted to small conic tubes and allocated in a greenhouse equipped with an intermittent mist. The plants cultivated in CC substrate and sprayed with 0.1 mg L-1 of BIOBRAS-16 showed higher growth of shoots with greater numbers of leaves, rosette diameter, leaf width, fresh and dry matter production at 150 days after planting. The plants that were cultivated on CC substrate and sprayed with BIOBRAS-16 at a 0.1 mg L-1 produced 2.8 times more dry matter than the control cultivated in Plantmax ® substrate. The fresh and dry matter of roots were superior in Plantmax ® when compared to CC at late sampling periods.

Micropropagation of Chapada Diamantina ornamental bromeliad

“…To ensure that the microplants survive during the acclimatization, roots must definitely be present. This step is critical for the micropropagation to succeed, because the heterotrophic state (in vitro) is altered to the autotrophic one (ex vitro) accompanied by water loss, which can lower the plant vigor and even induce mortality (CATUNDA et al, 2008;ROCHA et al, 2008;LIMA-BRITO et al, 2016). To facilitate the gradual adaptation to the new environmental conditions, the microplants may go through a hardening period in vitro or be subjected to water loss reduction strategies, post transfer.…”

Substratos alternativos para a produção de mudas de Angico Branco (Anadenanthera colubrina (Vell.) Brenan)

“…Neste sentido, os resíduos orgânicos que compõem os substratos devem apresentar a capacidade de produzir organismos a fim de promover o grau de fertilidade do solo e aumentar a eficiência da troca de cátions, que resulta na qualidade das mudas cultivadas nesse ambiente (Knapik et al, 2005). O uso de materiais alternativos provenientes de resíduos agroindustriais, como o bagaço da cana e torta de filtro de usinas (Catunda et al, 2008;Santana et al, 2012), e a casca de arroz carbonizada (Saidelles et al, 2009;Terra et al, 2011), foram estudados como substratos para produção de mudas (Grigatti et al, 2007).…”