In strawberry micropropagation, several challenges must be overcome to obtain quality plants and achieve high survival rate to ex vitro acclimatization. In this study, therefore, a set of protocols were evaluated to optimize explant (meristem) disinfection, in vitro growth (multiplication and rooting), and ex vitro acclimatization of strawberry. The results showed that explants treated with 1.0% NaClO for 5 min had a lower percentage of contamination, and achieved a higher percentage of viability, height, and number of leaves. In vitro growth was favored by the use of 1 mg L⁻¹ zeatin, since it allowed greater seedling growth (number of shoots, seedling height, number of leaves, number of roots and root length), and a higher pre-acclimation rate (100%). In the acclimatization phase, plants grown in a substrate composed of compost + peat combined with 4 g of humic acid achieved better response in morphological and physiological variables. In fact, the results of this study could be used to cultivate strawberry plants of the ‘Aroma’ variety with high commercial quality.

The assignment of accurate species names is crucial, especially for those with confirmed agronomic potential such as highland papayas. The use of additional methodologies and data sets is recommended to establish well-supported boundaries among species ofVasconcellea. Accordingly, six chloroplast (trnL-trnF,rpl20-rps12,psbA-trnHintergenic spacers,matKandrbcLgenes) and nuclear (ITS) markers were used to delimit species in the genusVasconcelleausing phylogeny and four DNA-based methods. Our results demonstrated congruence among different methodologies applied in this integrative study (i.e., morphology, multilocus phylogeny, genetic distance, coalescence methods). Genetic distance (ABGD, SPN), a coalescence method (BPP), and the multilocus phylogeny supported 22–25 different species ofVasconcellea, including the following five new species from northern Peru:V.badilloisp. nov.,V.carvalhoaesp. nov.,V.chachapoyensissp. nov.,V.pentalobissp. nov., andV.peruviensissp. nov. Genetic markers that gave better resolution for distinguishing species were ITS andtrnL-trnF. Phylogenetic diversity and DNA-species delimitation methods could be used to discover taxa within traditionally defined species.

Pineapple is a crop of great importance for the economic stability of a large number of Peruvians; however, in areas experiencing low degrees of technological intervention, farmers generally adopt low planting densities. The objective of this study was to determine the effect of three plantation densities (35700, 47600, and 55500 plants ha⁻¹) on the agronomic performance and fruit quality of three pineapple cultivars (“Golden,” “Smooth Cayenne,” and “Santa Rosa” ecotype). The experiment was performed under a randomized complete block design (RCBD) in a factorial arrangement, and the data were subjected to analysis of variance and the Tukey test ( ). The results show significant differences in terms of plant height and D-leaf length, with “Golden” being the cultivar that achieved the best performance at the three planting densities. The diameter (11.77–13.29 cm) and weight of the fruit without a crown (1.48–1.85 kg) were not affected by the treatments; in contrast, the length and weight of the fruit with a crown did exhibit significant variations, highlighting the “Smooth Cayenne” cultivar and “Santa Rosa” ecotype at a density of 55500 plants ha⁻¹, respectively. The highest estimated yield (>100 t ha⁻¹) for the three pineapple cultivars was recorded at a density of 55500 plants ha⁻¹. The content of total soluble solids was higher in the “Golden” cultivar, but in general, all the fruits exceeded the established standards. Based on the results, it is recommended that farmers in the area and those with similar conditions establish a planting density of 55500 plants ha⁻¹ because it improves the yield without damaging the quality of the fruit of the pineapple cultivars evaluated.

Lilies are one of the most important, beautiful, and economically valuable flowers in the world. Lilium is regarded as a popular floral trade cut flower, so viable protocols are needed to provide seed production, multiplication, and preservation. In vitro protocols allow for rapid large-scale production and rejuvenation of planting material, but to be a commercially viable multiplication method, the procedure must allow for rapid production of viable, true-to-type plants quickly. The objective was to evaluate the in vitro production of microbulbs of five lily varieties (Lilium Champion Diamond, Lilium Yellow Diamond, Lilium Batavus, Lilium Hyde Park, and Lilium sp.) using different concentrations of 6-benzylaminopurine (0, 0.5, 1.0, 1.5, 1.5, and 2.0mg L⁻¹ BAP) and to determine the commercial quality (flowering) of the plants grown from the seed obtained. Results from the micropropagation phase show Lilium Batavus and Lilium Hyde Park varieties had better in vitro responses, especially when grown with 1.0 and 1.5mg L⁻¹ BAP, respectively. Plants (of all varieties) grown from microbulbs showed positive growth and generally resulted in commercially viable flower production. Finally, the results of this study support the use of bulb scales as an alternative for obtaining vegetative seeds with high potential for lily cultivation.

Introduction. The nutritional properties, antioxidant capacity, and commercial value of the yellow dragon fruit are attractive for its sowing; therefore, it is necessary to study technological improvements for its propagation. Objective. To evaluate the feasibility of in vitro establishment and multiplication of yellow dragon fruit, with the use as explants of seedlings from the in vitro germination and various hormonal sources. Materials and methods. The experiment was developed in the Plant Physiology and Biotechnology Laboratory of the Universidad Nacional Toribio Rodriguez de Mendoza, Peru, between February and June 2020. Four treatments were evaluated for germination [control: sterile water (3 ml), E1: MS (50 %), sucrose (30 g L-1), agar (6 g L-1), E2: AG3 (250 mg L-1), E3: MS (100 %), sucrose (30 g L-1), agar (6 g L-1), AG3 (250 mg L-1)] and multiplication [control: MS (100 %), sucrose (30 g L-1), agar (7 g L-1), M1: MS (100 %), sucrose (30 g L-1), agar (7 g L-1), coconut water (10 ml L-1), M2: MS (100 %), sucrose (30 g L-1), agar (7 g L-1), coconut water (20 ml L-1), activated carbon (2 g L-1), M3: MS (100 %), sucrose (30 g L-1), agar (7 g L-1), BAP (0.10 mg L-1), ANA (3 mg L-1)]. The evaluated variables were: germination (%), number and length of shoots and roots, callus formation (%), rooting (%), and the number of areoles. Results. The best germination (100 %) was obtained in the E1 medium, with more than three roots and two shoots per seedling (2,64 cm). The M2 medium generated the best multiplication, with 82.5 % rooting, 1.66 cm shoots and 1.86 areoles, and less presence of callus tissue (60 %). Conclusion. The micropropagation of yellow dragon fruit was achieved by using seedlings obtained in vitro as an explant source.

Salinity is one of the main limiting factors for agricultural production worldwide. Nanotechnology has emerged as a possible tool to improve plant tolerance to salt stress. However, the application of zinc oxide (ZnO) nanoparticles in agriculture raises questions about their safety and long-term impact. The objective of this study was to investigate the effects of foliar application of ZnO nanoparticles on the physiology and defense systems of coffee plants in the presence/absence of NaCl (150 mM). A foliar spray of ZnO-NPs (0, 50, and 100 mg L⁻¹) was applied to coffee plants individually and in combination with simulated stress conditions. The results showed that the application of ZnO-NPs to plants under salt stress had both positive and negative effects. An increase in proline content ranging from 33% to 77% was detected in stressed plants treated with ZnO-NPs, in contrast to stressed plants that did not receive the application. CAT activity increased by 69.4% to 152.8% with the application of ZnO-NPs compared to plants under salt stress that did not receive the treatment. Additionally, the application of ZnO-NPs decreased H₂O₂ levels by up to 18.7% with respect to the control group. On the other hand, 45% higher Na⁺ accumulation was observed in NaCl-stressed seedlings treated with ZnO-NPs (50 mg L⁻¹). MDA levels in stressed plants treated with ZnO-NPs increased by 3% to 50%. Furthermore, the combined effect of ZnO-NP (100 mg L⁻¹) and salt resulted in a significant reduction in carotenoids, limiting their photoprotective function. The results obtained indicate the complex interaction between the application of ZnO-NPs and various physiological processes in coffee plants, including photosynthesis, antioxidant enzyme activity, and the generation of reactive oxygen species. This phenomenon requires detailed analysis to fully understand the response of coffee plants to ZnO-NPs’ application.