Effects of different light spectra on the slow-grown in vitro storage and quality of banana plantlets cv. Prata Catarina (AAB)

Integrated Analysis of Morphological, Physiological, Anatomical and Molecular Responses of Cassava Seedlings to Different Light Qualities

Light quality is highly important for growth control of in vitro plant cultures. Here, we investigated the effect of blue light (BL), red light (RL) and combined red and blue light (RBL) on in vitro cassava growth. Our results indicate that RL facilitated radial elongation of cassava and increased stomatal conductance as well as glucose, sucrose, fructose and starch content in leaves and cellulose content in the stem. It also enhanced SOD and POD activities but decreased the stomatal density and chlorophyll and carotenoid content in leaves. In addition, RL leads to shorter palisade cells, denser chloroplasts and more starch granules. These phenotypic changes were inverted following BL treatment. The expression levels of photosynthesis-related genes MeLHCA1, MeLHCA3, MePSB27-2, MePSBY, MePETE1 and MePNSL2 in leaves were at their lowest following RL treatment, while the expression levels of MePSB27-2, MePSBY, MePETE1 and MePNSL2 were at their highest after BL treatment. The phenotypic changes after RBL treatment were between the values observed for the RL and BL treatments alone. Moreover, the responses of SC8 and SC9 cassava varieties to light quality were largely conserved. As such, we believe that the results of this study lay the foundation for controlling the in vitro growth of cassava seedlings by light quality.

Volatile profile and micropropagation conditions of Bauhinia forficata Link

Bauhinia forficata Link. is a native South American plant, which possesses volatile compounds with pharmaceutical and medicinal properties such as antidiabetic and anti-inflammatory effects. However, the conservation and propagation of this plant are complicated by its recalcitrant seeds and delayed flowering transition. Hence, tissue culture is employed for the safe and efficient propagation of B. forficata. However, the optimal conditions for the in vitro cultivation of B. forficata remain unknown. Thus, this study aimed to characterize the volatile profile of adult B. forficata field plants and evaluate the effects of different light intensities (43 and 70 μmol m-2 s-1), gas exchange rates (14 and 25 µL L-1 s-1), and exogenous sucrose concentrations (0, 20, and 30 g L-1) on their in vitro development. The results showed that β-caryophyllene is the major volatile compound produced by B. forficata. Moreover, culturing in a medium containing 30 g L-1 of sucrose and flasks with membranes that allow CO2 exchange at the rate of 25 µL L-1 s-1 produced vigorous and hardened plants with high survival rates independent of irradiance. This study is the first to report the optimal in vitro culture conditions for B. forficata as a reference for future studies on micropropagation and secondary metabolite production using this species.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03634-8.

In Vitro Conservation through Slow Growth Storage Technique of Fruit Species: An Overview of the Last 10 Years

Plant genetic resources conservation may be a potential option for the improvement of agricultural crops through modern biotechnologies, and in vitro conservation is a tool available to safeguard plant biodiversity. Ex situ conservation of plant genetic resources using the in vitro procedures is in progress in many countries. The slow growth storage (SGS) technique is a valid in vitro approach to preserve several vegetatively propagated species by controlling the growth and development of plantlets, economizing storage space and labor and reducing costs. Moreover, SGS prolongs the timing between subcultures, lowers the risk of losing germplasm through handling errors, such as contamination problems, and decreases the risk of genetic instability due to the reduction in the number of subcultures. SGS is applied by considering different factors: temperature, light or darkness conditions, medium composition, including mineral or sucrose concentrations, and the presence/absence of plant growth regulators, osmotic agents and growth inhibitors. SGS protocols for some fruit species have been well defined, others require additional research. The present review focuses on the effect of several factors that influence the SGS of in vitro shoots derived from temperate and tropical fruit species during the last ten years.