Effects of different culture conditions (photoautotrophic, photomixotrophic) and the auxin indole-butyric acid on the in vitro acclimatization of papaya (Carica papaya L. var. Red Maradol) plants using zeolite as support

Abstract

Plant regeneration of papaya via organogenesis and somatic embryogenesis has been successful; however, the biggest problem of in vitro culture of this species is the acclimatization of regenerated plants, where over 70% of the plants are lost before being planted in the field. Decreasing the relative humidity inside the culture vessel and thus increasing the ventilation, appears to have a greater effect on the adaptation of papaya plants, strengthening the function of the stomata and with this, allowing better control of water loss from the leaves. The aim of this study was to determine the effects of different concentrations of sucrose and indole-butyric acid (IBA) on rooting and in vitro acclimatization of plants using sterile zeolite as support and culture vessels with increased ventilation. Three concentrations of sucrose (0, 10 and 20 g L-1) were studied with and without auxin and as the control treatment, the rooting culture medium with agar during 17, 27 and 37 culture days. The highest percentage of rooting was recorded at 37 culture days in the treatment without sucrose and IBA with 80.0% and zeolite as support. The best photosynthetic values were achieved when in vitro shoots were grown in culture medium with auxin and different concentrations of sucrose, even though they were also high in the treatment without the presence of IBA and without sucrose at 17 days of culture. The combined effect of the zeolite, auxin (IBA), without sucrose in the culture medium and increased ventilation allowed photoautotrophic culture conditions which had effect of the increasing plant survival under ex vitro acclimatization conditions.

The Effect of Sucrose Supplementation on the Micropropagation of Salix viminalis L. Shoots in Semisolid Medium and Temporary Immersion Bioreactors

“…Similarly, a correlation between sucrose supplementation, root system development and survival has been reported for other plants cultured by TIS such as Chinese ash [25], poplar [54] and bamboo [19]. In papaya, using a stationary liquid culture with zeolite supported more rooting and the survival of shoots cultured without sugar and exposed to high ventilation was reported [55]. Within plants cultured in SSM results seem to be more variable: grapevine and kiwi fruit shoots cultured in SSM rooted and acclimatized better with sucrose [56,57], in rapeseed no correlation could be established [45], whereas with thyme, paulownia, potato, tobacco and wasabi more roots were formed when less sugar was added to the culture medium [29,33,45,58].…”

Use of Biotechnological Methods to Support the Production of New Peach Hybrids

“…Previously, growth and physiological changes in some plant species under in vitro propagation have been described [27,28]. Insufficient work of the photosynthetic apparatus is associated with the addition of sucrose to the culture media and CO 2 deficiency [73,74].…”

“…Among the main causes of functional disorders in plants ex vitro are the imperfect functioning of the stomatal apparatus, poor development of the cuticle and non-functioning root system [13,19,20]. In this regard, some authors reasonably recommend the use of structural changes monitoring in the vegetative organs of investigated plants adapted ex vitro for the development and optimization of the clonal micropropagation protocol [14,[21][22][23][24][25][26], as well as to study their functional abilities [27,28].…”

Photosynthetic efficiency and in vitro growth of Celastrus paniculatus Willd. under varied concentrations of CO2

“…The photoautotrophic growth on sucrose-free medium has been observed in Cannabis, 46 Hypericum perforatum, 33 Cymbidium 29 and Carica papaya. 47 Regardless of the sugar contents in the medium, an increase in CO 2 concentration greater than the optimal concentration resulted in decreased growth in a few cases. This might be because of down regulation of photosynthesis found in plants growing under CO 2 enrichment 48,49 or may be due to their incubation under PAR limited conditions.…”