Agrobiotechnology

Water scarcity is one of the main challenges faced by modern agriculture, leading to a substantial drop in crop productivity and a threat to food security. Thus, novel agricultural approaches are necessary and urgent to face this problem. Some natural compounds such as amino acids have been shown to increase yield and mitigate the effects of drought stress. In this study, we demonstrate that the application of pyroglutamic acid (PG) is capable of increasing lettuce yield, under field conditions with 30% less than optimal irrigation. PG treatment showed a clearly protective effect in stressed plants, enhancing their fresh weight by 37% and yield by 31%, in comparison to untreated plants. PG appears to promote drought tolerance effects in deficit irrigated lettuce plants, with several advantages. It acts by enhancing photosynthesis rate and antioxidant defences, while maintaining osmotic and water balance, without toxicity to soil microorganisms. This illustrates the potential use of PG to combat productivity losses due to water scarcity.

Salinity and drought are considered significant abiotic plant stressors with major impact on plant development that causes serious agricultural yield losses. Amongst the strategies to face this problem, the use of compounds capable of inducing abiotic stress tolerance is still little explored. Menadione sodium bisulphite (MSB), a water-soluble vitamin K3 derivative, was previously shown to prime salt stress tolerance when Arabidopsis seeds were pre-soaked with this compound. However, this method has some technical problems regarding seed storage and longevity. In order to overcome these handicaps, we assessed the effect of supplying MSB to roots to prime the response to salinity stress, analysing the effect of two NaCl concentrations (100 and 150¿mM). We selected tomato plants, the most economically important horticultural crop, as our biological model. In this new system, MSB primes salt tolerance in tomato plants by improving net photosynthesis, regulating stomatal aperture and maintaining water balance. Furthermore, MSB induces a faster proline accumulation and ion homeostasis by up-regulating several ion transporter genes, and increases antioxidant activity. As a result, a clear positive effect on plant growth was observed, indicated by the relative growth rate (RGR), These findings again highlight the potential usefulness of MSB as a priming agent for enhancing crop tolerance in the field under adverse environmental conditions.

In the Andean region, Philippines, and central Africa most guinea pigs are raised for meat production. Guinea pig meat is of increasing interest to researchers. One of the critical questions in meat production is to know when muscles convert to meat. The objective of this study was to describe the pH evolution in guinea pig muscles and to determine the establishment and resolution time of rigor mortis. Forty-eight guinea pig carcasses were divided into four groups: 12 male and 12 female of 3 month-old fattened animals, and 12 male and 12 female of 12 month-old reproductive animals. The pH was measured using a penetration probe in Longissimus thoracis, Quadriceps femoris, Triceps brachii and Psoas major muscles for 24 h, and rigor mortis was monitored during this time. The initial and final pH ranged between 6.56–7.00 and 5.97–6.27, respectively. Rigor mortis was established at ∼5 h and resolved at ∼15 h postmortem. The Psoas major was the muscle with lower initial pH and higher final pH, while no differences were found between the other muscles. Initial, evolution and final pH were not affected by the sex. No differences were found in the productive-reproductive status between males, whereas the older female guinea pigs presented higher pH in three muscles. In conclusion, in our test conditions final pH in guinea pigs remains high enough to permit microbial growth, which could affect the shelf-life of Guinea pig meat. Moreover, it is recommended to keep guinea pig carcasses in refrigeration until 15 h postmortem, when rigor mortis is resolved, and muscle-to-meat conversion finished. Management of these carcasses should be different depending if the animals belong to a productive or reproductive animal system. It is therefore necessary to chill guinea pig carcasses at least 15 h, to achieve a correct muscle-to-meat conversion.

Several physiological and metabolic changes take place in dairy ruminants around parturition (late pregnancy, parturition, and early lactation). Dairy species are genetically selected for their higher milk production compared with non-dairy species. This fact causes a constant stress that impairs the immune status of the animal, with consequences for its welfare and performance. In the present study, we assessed the immune status of high-yield dairy sheep and goats by quantifying IgG and IgM concentrations, as well as chitotriosidase (ChT) and complement system [total complement system (TC) and alternative complement pathway (AC)] activity in blood plasma around parturition. We also measured IgG and IgM concentrations and ChT activity in colostrum and milk during the first 40 d postpartum. The lowest blood IgG concentration was at parturition in both species. We detected no differences in blood IgG concentrations between species. Blood IgM concentrations were constant in both species throughout the study period. However, blood IgM concentrations were greater in sheep than in goats. Blood ChT activity was greater in goats than in sheep, and both species showed constant activity of this enzyme throughout the study period. We observed no differences in complement system (TC and AC) activity between sheep and goats. In addition, both TC and AC activity were constant in both species throughout the experiment. In general, IgG and IgM concentrations were greater in sheep colostrum than in goat colostrum, but these differences disappeared after d 4 (IgG) and d 3 (IgM) postpartum. In both species, the highest IgG and IgM concentrations were measured in colostrum, gradually decreasing during the first days postpartum. Chitotriosidase activity decreased in both species from colostrum to milk, although goats always showed greater ChT activity than sheep. Both sheep and goats seemed to be more susceptible to infectious diseases around parturition. As well, goats showed greater ChT activity in blood, colostrum, and milk than sheep. This fact may give these animals additional protection against parasite and fungal infections.

Previous studies in mango (Mangifera indica) had reported how low pollen viability can reduce yields. In this work, an improved in vitro pollen germination method for mango is used to assess germination range at different environmental conditions. Since mango is an andromonoecious species, pollen performance was studied in hermaphrodite and male flowers. The results showed a similar number of pollen grains per anther and pollen viability and germination between the two mango flower morphs. Pollen germination was also studied at different temperature conditions, and results showed that percentage of pollen germination improved along the flowering season with increasing temperatures. Pollen germination at controlled temperatures slowed down at low temperatures. Differences were found between genotypes in pollen behavior at different temperatures opening the possibility of selecting mango genotypes with pollen more adapted to cold temperatures, especially for subtropical conditions.

This study aims to identify the factors that constitute the social value of heritage in relation to sustainable tourism. To do so, this paper provides a theoretical contribution by unifying the fields of heritage management and sustainable tourism through a mixed-method approach. It showcases the social dimension of the World Heritage Site of Altamira, Spain, combining qualitative and quantitative techniques. Research findings provide information about the multiple factors determining the social value of heritage, namely: existential, aesthetic, economic, and legacy values and the risks associated with underestimating the contemporary social value. Ultimately, this research paves the way for improving normative approaches toward sustainable tourism and, offers practical solutions to the challenges faced by the Altamira and other World Heritage Sites.