Paulo Hercílio Viegas Rodrigues

Unlike conventional crops, medicinal plants require continuous physiological monitoring, since their pharmacological compounds are synthesized through stress-sensitive secondary metabolism. In this context, accurate and non-destructive methods for determining chlorophyll content could be valuable tools for assessing the physiological status of these species. Thus, Mikania laevigata Sch. Bip. ex-Baker, widely used in herbal medicine, can benefit from chlorophyll monitoring to enhance its cultivation. This work was developed in order to evaluate the potential of the ClorofiLOG® index as a non-destructive predictor of leaf pigment concentrations in M. laevigata during the vegetative stage. Plants were cultivated for 60 days in greenhouse conditions, and both destructive (spectrophotometric) and non-destructive pigment measurements were collected from medium leaves. Linear regression equations were adjusted between the index and the concentrations of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids. The adjusted models yielded high coefficients of determination for total chlorophyll and chlorophyll b, with a moderate value for carotenoids. Predictive performance of the adjustments, assessed by the ratio of performance to deviation, was classified as “very good” for total chlorophyll (2.91) and chlorophyll b (2.67), and “weak” for chlorophyll a (1.79) and carotenoids (1.43). Therefore, models based on the ClorofiLOG® index are suitable for non-destructive estimation of total chlorophyll and chlorophyll b in M. laevigata, supporting its application as a practical tool for the physiological monitoring of this species. This approach may assist in the early detection of plant stress, guide nutrient management decisions, and contribute to optimizing cultivation strategies for this medicinal species under both experimental and production-scale conditions.

Indoor green plants, such as the Anthurium plowmanii (Anthurium Bird Nest group), are used to balance the domestic environment in large cities and stand out in this market. This study aimed to evaluate in vitro plantlets of Anthurium plowmanii cultivated under 30% photo-selective nets in the red, blue, and black spectra, and two kinds of pots, opaque and translucent. After one year of cultivation, plants under the red net showed a higher number of leaves per pot, fresh mass, and leaf length, regardless of the pot type. The roots were influenced by the type of pot, with a higher thickness of velamen in the roots grown in opaque pots. The presence of chloroplasts and chlorophyll in the cortical parenchyma of the roots is exclusively in translucent pots. No root escape was observed in either treatment at the end of the 12-month cultivation period.

Plant species sensitive to desiccation or vegetatively propagation are difficult to store and transport in the germplasm for space travel. Applying plant tissue culture can help to create a Plant Germplasm Bank for this species. For this purpose, the Compact Growth Chamber (CGC) was created to store and transport in vitro explants, maintaining them for long periods in Slow-Grown Storage (SGS). Explants under SGS have reduced growth metabolism to complete space missions. This study aimed to evaluate the CGC efficacy in the long term of in vitro storage of explant of Taioba (Xanthosoma sagittifolium), a tropical species that vegetatively propagates and has high nutritional value. For this, three CGCs were connected, side by side, with different LED light spectra (CGC1: Red spectrum; CGC2: 50% Red + 50% Blue spectra-control; CGC3: Blue spectrum), each one containing nine test tubes with taioba explants (one per test tube), and LED lights intensity adjusted for 30 µmol m⁻² s⁻¹. The CGCs were maintained for 120 days in the darkroom, at 25 ± 2 °C temperature and 50–60% humidity, and, at the end, the growth and morphological parameters of taioba plantlets were evaluated. These results demonstrate that the explant storage in CGC3 showed lower root numbers and root lengths than in CGC1 and CGC2. In addition, the Blue spectrum in CGC3 reduced the root oxidation and browning, resulting in 100% live explants. This study provides that the CGC fulfilled its proposed function of transporting and storing the in vitro explants for space travel.

The efficacy and safety of phytotherapeutic medicines are intrinsically related to the quality of their plant-based raw materials, which is directly influenced by agronomic cultivation practices. The objective of this study was to evaluate the effects of colored shade nets and foliar application of ProLyks® on the growth and secondary metabolism of Mikania laevigata Sch. Bip. ex-Baker. The experiment followed a completely randomized 4 × 5 split-plot design, with three photoselective shade nets (red, blue, and black) compared to full sunlight (control) and five ProLyks® doses (0.00, 0.25, 0.50, 1.00, and 2.00 mL·L⁻¹). Significant interactions between these factors were observed for plant height, number of leaves, leaf dry matter, and coumarin content. The red net promoted the highest biomass production and, when combined with the 1.5 mL·L⁻¹ ProLyks® dose, also maximized coumarin accumulation in leaves, indicating a possible elicitor effect under these conditions. A considerable positive correlation between plant height and coumarin content suggests that taller plants may serve as a practical field indicator of superior pharmaceutical quality. Additionally, an inverse correlation between total chlorophyll and flavonoid content highlights a trade-off between photosynthetic pigment synthesis and secondary metabolism. These findings demonstrate that red shade nets combined with the optimal ProLyks® dosage can enhance both biomass yield and phytochemical production in M. laevigata, while also providing useful indicators for field selection of high-quality materials for the national pharmaceutical industry.

Plant species sensitive to desiccation are difficult to store and transport in the germplasm bank for space travel. Applying plant tissue culture can help to create a Plant Germplasm Bank for this species. For this purpose, the Compact Germplasm Bank (CGB) was created to store and transport in vitro explants, maintaining them for long periods in slow-grown storage. This study aimed to evaluate the CGB efficacy in the storage in vitro explant of Taioba (Xanthosoma sagittifolium). For this, three CGBs were connected, side by side, with different LED light spectra (CGB1: Red spectrum; CGB2: 50% Red + 50% Blue spectra; CGB3: Blue spectrum), containing each one nine test tubes with taioba explants (one per test tube), and LED lights intensity adjusted for 30 µmol m^-2s^-1. The CGBs were maintained for 120 days in the darkroom, at 25^oC temperature and 50-60% humidity. Explant storage in CGB3 showed lower root numbers and root lengths than in CGB1 and CGB2. The Blue spectrum in CGB3 reduced the root oxidation and browning, resulting in 100% live explants. The CGB fulfilled its proposed function of storing the in vitro explants.

The efficacy and safety of phytotherapeutic medicines are intrinsically related to the quality of their plant-based raw materials, which is directly influenced by agronomic cultivation practices. In this scenario, this study aimed to evaluate the effects of colored shade nets and foliar application of D-limonene on the growth and secondary metab-olism of Mikania laevigata Sch.Bip. ex Baker. The experiment followed a completely randomized 4 × 5 split-plot design, with three photoselective shade nets (red, blue and black) compared to full sunlight (control) and five D-limonene doses (0.00, 0.25, 0.50, 1.00, and 2.00 mL L⁻¹). Our findings revealed significant effects on plant height, number of leaves, stem diameter, and leaf dry matter. The red net promoted greater shoot biomass accumulation and increased leaf dry mass. Regarding secondary metabolites, the red and black nets enhanced coumarin content by 18.80% and 15.36%, respectively, compared to full sunlight cultivation. D-limonene positively influenced biometric traits up to 1.20 mL·L⁻¹, followed by a decline. These findings indicate that colored shade nets could be an effective approach to enhance the phytochemical yield of M. laevigata, while D-limonene contributes mainly to morphological development and biomass accumu-lation.

The production of gerbera (Gerbera jamesonii) under greenhouse conditions often involves shading techniques to control micrometeorological conditions and fertigation to optimize plant nutrition. This study aimed to evaluate the chlorophyll index, leaf area and yield characteristics of potted gerbera (‘Red with Eye’ cultivar). A randomized complete block design was adopted, in a 4 × 3 factorial arrangement, with four concentrations of the fertigation nutrient solution (50, 75, 100 and 125 %) and three shading net colors (red, blue and black). The chlorophyll indices, leaf area and dry masses of the flower capitula, stem and leaves were evaluated. The highest chlorophyll indices were observed under red and black nets at the highest nutrient concentration. The leaf area followed a quadratic response to the nutrient concentration, with a maximum value of 82.9 %. For the dry masses, there was a significant interaction between the factors. Under the blue net, the greatest dry masses were obtained at nutrient concentrations of 93-98 %, whereas, under the red net, the highest values occurred at the 50 % concentration and was recommended as the most efficient treatment.

Adequate fertilizer concentration and use of shade nets can favor the development and yield of agricultural crops. The objective of this investigation was to evaluate the growth of roselle plants with nutrient solutions of different electrical conductivities (EC_ns) (1.0, 2.0, 3.0, 4.0 and 5.0 dS m⁻¹) and under different colored shade nets (red, blue, black) compared with full sun. The experiments were conducted in a controlled greenhouse environment and in full sun in the Plant Production Department of ESALQ-USP, Piracicaba, SP, Brazil. The experiments were organized using a 4 × 5 randomized block design. The results of analysis of variance and regression showed a significant impact of EC and colored shade nets on plant height, stem diameter, number of leaves, number of flowers, fresh and dry mass of shoots and fresh and dry calyxes. The data were subjected to analysis of variance and regression, which showed a quadratic effect for the variables studied, with increasing values up to 3.0 dS m⁻¹; after this value, there was a decrease. Increasing EC_ns up to approximately 3.0 dS m⁻¹ promoted increments of 2.34% in plant height, 7.21% in number of leaves, 19.76% in shoot fresh mass and 12.38% in shoot dry mass.

The objective of this work was to evaluate the effect of different LED light spectra on the in vitro rhizogenesis of microcuttings of blueberry 'Jewel', without the use of growth regulators. The plantlets were subjected to four LED light treatments, as follows: R, 100% red; R2B, 70% red and 30% blue; B, 100% blue; and CW, control white. After six weeks incubated in a culture room, R and R2B treatments show statistically significant effects on the in vitro rooting of blueberry.