Opuntia spp. are cacti with high ecological, economic and conservation interest in semiarid environments, particularly in Mexico. We conducted a systematic search of the existing peer-reviewed literature about the state of knowledge of pollination ecology on these plants. We documented the most studied Opuntia species worldwide with an emphasis on Mexico. We found that only 15% of Opuntia species described have been investigated so far, and studies were mainly focused on comprehension of the biology of a single species. Despite the economic and cultural importance of Opuntia, there is a significant lack of knowledge about the flower-visiting insects and their taxonomic identity. We provide a checklist of the insect species associated with Opuntia spp. Through a circular network, we visualize the complex Opuntia flower-visiting insect relationship, and we detected a set of key species constituting the generalist core of the networks constructed. Since pollination is crucial for crop production, a better understanding of ecological interactions would inform management measures to strengthen biodiversity and agriculture sustainability as well as productivity in arid and marginal lands. Further research on pollination ecology is needed to improve the conservation status of the insects associated with Opuntia species.

Tetraclinis articulata (Vahl) Masters is an endangered tree growing in coastal and arid environments that is widely exploited by the timber and resin industry, among other applications. In this context, the use of in vitro techniques is highly encouraged for its propagation. We present a protocol for micropropagation using twigs from adult trees as a source of explants. The Schenk and Hildebrandt basal medium (SH) supplemented with 30 g L⁻¹ sucrose, 6.5 g L⁻¹ plant agar, 4.0 mg L⁻¹ 6-benzyladenine (BA), and 0.05 mg L⁻¹ 1-naphthaleneacetic acid (NAA) provided the optimum multiplication rate (90.48 ± 9.52 explants with basal shoots and 2.58 ± 0.29 basal shoots per explant). Application of activated charcoal (AC) or ½ Knop solution in a liquid overlay produced significantly longer shoots. Supplementation of solid media with indole-3-butyric acid (IBA) or NAA gave low rooting percentages (<17%). Addition of 0.9 g L⁻¹ AC improved rooting (40%) but rooting performance was optimal (66.7%) after a pulse treatment consisting of 4 h immersion in liquid SH medium without growth regulators, followed by 8 weeks of cultivation. Rooted microplants were successfully acclimatized (93.33%) in a peat moss and vermiculite mixture (1:1 v/v ratio). The genetic stability of the in vitro regenerated plantlets was confirmed using the randomly amplified polymorphic DNA (RAPD) technique. Explant survival and growth remained higher than 90% after 28 weeks of cold storage at both 4 °C and 10 °C. The protocol presented here allows for largescale T. articulata production and could be applied for both ex situ conservation strategies and industrial purposes.

Thymus L. is of great interest in horticulture as ornamentals, spices, and medicinal plants, as well as in the extracts industry due to the richness in bioactive specialized metabolites. The natural hybrid T. × josephi-angeli Mansanet & Aguil. is produced in Spain, as its horticultural forms are very popular for domestic uses and gardening. However, its micropropagation and chemical composition have not been studied yet. Therefore, the main objective of this work was to develop a micropropagation procedure for T. × josephi-angeli, and to check whether the in vitro culture had an impact on the chemical profile of the plants. The results showed a high initiation rate (>91%) after two sterilization treatments were applied. Moreover, a micropropagation rate of around 21 new rooted explants per culture cycle was obtained in treatment M7 (Murashige and Skoog with 0.064 µM 6-(γ,γ-Dimethylallylamino)purine) when compared to the other 10 treatments performed. Acclimatization was successful in all three approaches tested (>75%), and all plants kept growing after 4 months of outdoor cultivation. Finally, 36 volatiles were identified, and the content of major compounds remained not statistically different in acclimatized plants when compared to the wild-type plants according to the analyses made by HS-SPME-GC/MS and SPME-GC/MS. This chemical stability points out the uniformity of the microplants and the suitability of the procedure applied in this study for T.×josephi-angeli horticultural production using in vitro techniques.

Maralfalfa (Cenchrus purpureus (Schumach.) Morrone) is a productive fodder crop in tropical regions that has been evaluated for forage nutritional value in a Mediterranean climate. To assess the nutritional value, parameters including dry matter content (DM), ash, ether extract (EE), protein (CP), fiber contents (NDF and ADF), and the amino acids profile were determined at eight harvest times (HTs) in a non-fertilized and non-irrigated crop based in Silla (Valencia, Spain). The results showed significant differences in most of the parameters studied. While CP and ash significantly decreased over the eight HTs, NDF and ADF increased. In contrast, EE and the ratio of essential amino acids/total amino acids remained constant. Values of CP remained higher than 15% during the first two HTs (16 and 28 days). According to the analyses performed, the optimum HT can be stated at 28 days as it combines high levels of CP (including an optimal combination of essential amino acids) with low levels of fibers (NDF = 57.13%; ADF = 34.76%) and a considerable amount of dry matter (15.40%). Among the essential amino acids (EA) determined, lysine and histidine showed similar values (Lys ≈ 6%, His ≈ 1.70%) when comparing the composition of these EA to other forage species and cultivars studied, whereas methionine showed lower values. This work establishes the basis for the appropriate HT of maralfalfa according to the nutritional parameters measured. Further studies could be aimed to optimize the nutritional and phytogenic properties of maralfalfa to improve its value as a fodder crop, and to finally introduce it for sustainable livestock production in Mediterranean countries.