Aclimatização de porta-enxertos de Prunus sp. micropropagados

Abstract

A fase de aclimatização é considerada limitante para a maior parte das plantas micropropagadas pelas altas taxas de perdas que podem acarretar. A cultura in vitro tem determinado, para algumas espécies, a alteração de características morfológicas, anatômicas e fisiológicas que dificultam a sua aclimatização. O objetivo deste trabalho foi avaliar a sobrevivência de plantas dos porta-enxertos de Prunus Capdeboscq e GF677, e das seleções VP411 e VP417 durante o processo de aclimatização. Brotos com 2-3 cm foram inoculados em meio de cultura Lepoivre, suplementado com 0,1; 0,5; 1,0 e 2,0 mg.L-1 de AIB. Após 15 dias as plantas foram transferidas para bandejas alveoladas contendo substrato comercial Plantmax ®, cobertas com uma lâmina de vidro transparente e mantidas em sala de aclimatização, com temperatura de 27±1ºC, fotoperíodo de 16 horas, intensidade luminosa de 60mmol.m-2.s-1 e posteriormente em câmara de nebulização intermitente. A percentagem de sobrevivência das plantas foi afetada significativamente pela concentração de AIB, pelo genótipo e pela interação concentração de AIB x genótipo. As maiores taxas de sobrevivência foram de 92% para o porta-enxerto Capdeboscq na concentração de 1,0 mg.L-1 de AIB; 80% para a seleção VP417 com 0,5 mg.L-1; 84% para a seleção VP411 e 64% para o porta-enxerto GF677, ambos com 0,1 mg.L-1 de AIB. A formação de calos na base dos explantes afetou negativamente a sobrevivência das plantas.

Effect of Cytokinins, Carbohydrate Source and Auxins on In Vitro Propagation of the ‘G × N-9’ Peach Rootstock

“…In relation to the percentage of surviving plants (Figure 2c), although not statistically differences were observed, the results were encouraging, probably due to good quality aerial parts and root systems formed during in vitro growth (Figure 2d-g). Similar results have been reported previously for most rootstocks (Vujovic et al, 2012;Zhou et al, 2010), except Gisela 5 (Rogalski et al, 2003a(Rogalski et al, , 2003b.…”

“…In our study, poor shoot growth and development was observed in the absence of IBA and at an IBA concentration of 0.3 mg L −1 . According to Rogalski et al (2003b), this phenomenon may be directly related to the effect of IBA on explant apex growth and/or the occurrence of competition between explant apex and root growth. In relation to the percentage of surviving plants (Figure 2c), although not statistically differences were observed, the results were encouraging, probably due to good quality aerial parts and root systems formed during in vitro growth (Figure 2d-g).…”

Technical Glitches in Micropropagation

“…This stage is followed by a process called acclimatization and is essential because the in vitro plants are cultivated under heterotrophic conditions [8]. Morphological anomalies, such as nonfunctional stomata, and physiological anomalies, such as a decrease in photosynthesis, might occur during this process [9]. These anomalies interfere with plant survival in the greenhouse or field.…”

Biochemical profile of callus cultures of Pogostemon cablin (Blanco) Benth

“…These differences were also observed among plants of the same accession in different types of cultures, which may be due to the different requirements these plants have for the tested metabolites. Several studies have demonstrated that during cultivation in vitro, plants undergo alterations in metabolism; for example, gas exchange and photosynthesis decrease (Rogalski et al 2003). These changes could have influenced the accumulation of total and reducing sugar and of amino acids in leaf tissues.…”