Diversidad genética del aguacate criollo en Nayarit, México, determinada por ISSR

Avocado fruits are nutritious and highly accepted for fresh consumption. Mexico is one of the world’s largest producers and consumers of avocado. The geographical and edaphoclimatic conditions of Nayarit, Mexico, have been ideal for reproducing the genus Persea, hence the large avocado gene pool. This research analyzes the genetic diversity of native Persea americana from Nayarit using the highly polymorphic ISSRs genetic markers. We collected 43 samples of native avocado from five municipalities in Nayarit. The level of genetic diversity detected was 64 %, and the analysis of molecular variance indicated that the most significant variation is within populations (82 %). Dice’s genetic distance clustered the genotypes among groups according to genetic distances, and the clusters were associated with geographical or climatic conditions. Therefore, the information generated by this research can be useful in developing crop conservation and management strategies.  Los frutos de aguacate son nutritivos y de gran aceptación para su consumo en fresco. México es uno de los países con mayor producción y consumo de aguacate a nivel mundial. Las condiciones geográficas y edafoclimáticas de Nayarit, México, han sido idóneas para la reproducción del género Persea, por lo que existe un gran acervo genético del aguacate. El objetivo fue analizar la diversidad genética de Persea americana criollo del estado de Nayarit con los marcadores genéticos ISSR que son altamente polimórficos. Se recolectaron 43 materiales de aguacate criollo en cinco municipios de Nayarit, México. El nivel de diversidad genética detectado fue del 64 %, mientras que el análisis molecular de varianza indicó que la mayor variación se encuentra dentro de las poblaciones (82 %). La distancia genética de Nei y Li (Dice) agruparon los genotipos entre grupos de acuerdo con las distancias genéticas y se observó que la agrupación en la mayoría de los nodos estuvo asociada a la situación geográfica o climática. La información generada de esta investigación puede ser útil para construir estrategias de conservación y manejo del cultivo

An Explanatory Model for the Relationship between Motivation in Sport, Victimization, and Video Game Use in Schoolchildren

(1) Background: Society is changing amazingly fast, and this is bringing about changes in the way that people spend their free time. In the 21st century, free time is increasingly spent using technological devices such as video games, thus increasing levels of sedentariness. The aim of the present study was to define an explanatory model for the problematic use of video games, physical activity, motivational climate in sports, and victimization in schoolchildren, and to analyze the relationships between these variables according to gender; (2) Methods: A total of 734 schoolchildren, of both sexes, participated in this research study. They were aged from 10 to 12 and lived in the province of Granada (Spain). The main instruments used were the questionnaires PMCSQ-2, PAQ-C, QERV, and SVS. A multigroup structural equation model was used, which had an excellent fit (χ2 = 319.472; df = 72; р< 0.001; CFI = 0.962; NFI = 0.952; IFI = 0.962; RMSEA = 0.048); (3) Results: The practice of physical activity was related negatively and indirectly to the problematic use of video games ((r = -0.085, boys); (r = -0.081, girls)), and this in turn was related positively and directly to victimization ((r = 0.094, boys); (r = 0.174, girls)). Additionally, task climate was inversely related to the problematic use of video games for girls (r = -0.133), and ego climate was directly related to the use of these devices only with regard to boys (r = 0.250). (4) Conclusions: It must be noted that schoolchildren’s pathological use of video games is closely related to lower levels of physical activity. In addition, those motivational climates in sports that are oriented towards performance exacerbate this pathological behavior, which accentuates the importance of promoting motivational climates that are oriented towards tasks in schoolchildren.This work was supported by “Precompetitive Research Projects for Young Researchers 2017”—Modality B under de Grant PPJI_B-05, the project “DISPERSA” under the Grant TIN2015-67149-C3-R and European Regional Development Fund (ERDF) under the Grant P11-TIC-7486

Expression profile of EXP, Succ-CoA and ALDH genes in soursop (Annona muricata L.) fruits during ripening in response to refrigeration conditions

254-262Soursop (Annona muricata L.) is a climacteric fruit characterized by its rapid softening. Although many studies have improved the understanding of postharvest shelf life in soursop, the expression of genes involved in the loss of flesh firmness, organic acids and acetaldehyde metabolism are less well understood. We evaluated the expression profile of genes related to fruit softening, tricarboxylic acid cycle and acetaldehyde metabolism during ripening of soursop fruit stored at 28 ± 2oC and 15 ± 2oC. The fruit stored at 15 ± 2ºC prolonged the postharvest shelf life up to 9 days and showed higher firmness at 3 days compared to those stored at 28 ± 2ºC. Moreover, the postharvest storage at 15 ± 2ºC induced the expression of expansin (EXP),  succinyl CoA ligase (Succ-CoA) and aldehyde dehydrogenases  (ALDH) genes at 3 days. On the other hand, we recorded an increase in the gene expression of EXP and Succ-CoA at 6 days in fruit stored at 28 ± 2ºC. Based on the different gene expression patterns, we concluded that the postharvest storage at 15 ± 2ºC triggers the expression of EXP, Succ-CoA and ALDH genes at the early stages of soursop ripening. This suggests their role in cell disorganization, organic acids, acetaldehyde metabolism as well as in response to refrigeration during ripening

Differential Responses of Antioxidative System during the Interaction of Soursop Fruits (Annona muricata L.) and Nectria haematococca at Postharvest Storage

Soursop fruit (Annona muricata L.) production is diminished by the attack of pathogens such as Nectria haematococca. However, the fruit–pathogen interaction at the biochemical and molecular levels is still unknown. The objective of this study was to analyze the response of the soursop fruit to the presence of N. haematococca during postharvest storage. Soursop fruits were inoculated with the pathogen and total phenolic compounds, antioxidant capacity by Ferric reducing/antioxidant power (FRAP), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS•+), and 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH•), as well as enzymatic activity and transcript levels of polyphenol oxidase (PPO) and superoxide dismutase (SOD), were evaluated at 1, 3, and 5 days of storage. The noninoculated fruits were the controls of the experiment. The highest total phenol content was recorded on day one in the inoculated fruits. FRAP, ABTS, and DPPH activity presented the highest values on day three in the control fruits. Inoculated fruits recorded the highest PPO activity on day five and a five-fold induction in the PPO transcript on day three. SOD activity showed a decrease during the days of storage and 10-fold induction of SOD transcript on day three in the inoculated fruits. Principal component analysis showed that total phenols were the variable that contributed the most to the observed variations. Furthermore, a positive correlation between total phenols and SOD activity, PPO expression, and SOD expression, as well as between DPPH and FRAP, was recorded. The results showed a differential response in antioxidant capacity, enzymatic activity, and gene expression during the interaction of soursop fruits–N. haematococca at postharvest storage

Antioxidant enzymes and antioxidant activity in two soursop selections (Annona muricata L.) from Nayarit,Mexico stored at 15 °C

Abstract The changes in concentration of vitamin C, enzymatic and antioxidant activity during the ripening of two soursop selections (G1 and G2) at room temperature (22 ºC) and refrigeration (15 ºC) with an HR 85% were evaluated. The content of soluble protein, the activity of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), the concentration of vitamin C, as well as the antioxidant activity was evaluated by DPPH, ABTS and FRAP methods. The initial soluble protein concentration of the G1 and G2 selections diminished at 22 and 15 °C during ripening. Fruits stored at 22 °C showed the highest CAT activity. The maximum activity of SOD was recorded on the sixth and fourth day in fruits stored at 22 and 15 ºC, respectively. Fruits stored at 22 °C recorded the highest amount of vitamin C. Fruits stored at 22 and 15 ºC showed the highest antioxidant activity on the fourth day. The fruits stored at 15 ºC was able to increase the shelf life up to 8 days without affecting the ripening process. Therefore, the enzymatic and antioxidant activity has an important role in the possible alteration that the fruit might suffer during its fruit ripening

Cold Storage of Two Selections of Soursop ( Annona muricata

The maturity of two selections of soursop (G1 and G2) from Nayarit, Mexico, was evaluated under environmental conditions at 22°C and refrigeration at 15°C stored for 6 and 8 days, respectively. Maximum CO2 and ethylene values were present on the fifth and sixth day. The fruits exposed at 15°C had a significantly lower weight loss (5%) and showed no chilling injury. The firmness of two selections decreased more than 90%. The concentration of TSS increased to 5.3 to 15°Brix, and the titratable acidity was higher for fruit stored at 22°C. The highest concentration of phenols was recorded on the fourth day of storage at 22°C. The enzymatic activity of PPO was increased from physiological ripening to consumption ripening for both treatments. The two selections stored at 22°C registered the highest level of PME activity at ripeness. Shelf life was increased by up to 8 days (4 days at 15°C plus 4 days at 22°C) without causing chilling injury or alterations in the ripening process of the fruits. No significant differences were observed between the two selections evaluated; postharvest handling was considered to be similar; however, it would be advisable to evaluate other technologies combined with refrigeration

Edible Coating Based on Roselle (Hibiscus sabdariffa L.) Mucilage Applied to Soursop Fruits in Postharvest Storage

The soursop fruit (Annona muricata L.) is a crop of significant economic value for Nayarit, which is characterized by having a bittersweet taste, making it attractive to the consumer. However, the soursop has rapid maturation which causes a short shelf life. Several postharvest management techniques have been applied to reduce its metabolic processes, such as refrigeration, use of 1-methylcyclopropene (1-MCP), and controlled and modified atmospheres. In recent years, polysaccharide-based coatings have been applied to fruits. Therefore, the objective of this investigation was to evaluate the physicochemical and biochemical changes, as well as the antioxidant activity of soursop fruits with a mucilage-based coating (2%), stored at 22°C and 15°C with a 90% RH. Weight loss, firmness, color, soluble solids, acidity, pH, phenols, flavonoids, vitamin C, and antioxidant activity were evaluated. The results obtained in the coated fruits stored at 15°C showed lower weight loss (6.4%), lower firmness (29.7 N), higher TSS concentration (10.4°Bx), and lower acidity (0.38%) compared with the uncoated fruits. The total phenolic content decreased in coated fruits stored at 22°C (54.3 mg EGA/100 g FW). The highest antioxidant activity (DPPH method) was recorded in fruits coated and stored at 15°C with an average value of 257.9 mg EAA/100 g FW. Moreover, a high concentration of vitamin C was observed in fruits coated and stored at 15°C and 22°C (20.5 and 17.5 mg EAA/100 g FW), concluding that the coating based on roselle mucilage (2%) in combination with a temperature of 15°C prevents weight loss, decreases titratable acidity, and increases the content of phenols and vitamin C. Furthermore, an increase in the shelf life up to eight days and in the antioxidant activity at the maturity of consumption was observed in the fruits coated with 2% roselle mucilage stored at 15°C

Transcriptome Analysis of Soursop (<i>Annona muricata</i> L.) Fruit under Postharvest Storage Identifies Genes Families Involved in Ripening

Soursop (Annona muricata L.) is climacteric fruit with a short ripening period and postharvest shelf life, leading to a rapid softening. In this study, transcriptome analysis of soursop fruits was performed to identify key gene families involved in ripening under postharvest storage conditions (Day 0, Day 3 stored at 28 ± 2 °C, Day 6 at 28 ± 2 °C, Day 3 at 15 ± 2 °C, Day 6 at 15 ± 2 °C, Day 9 at 15 ± 2 °C). The transcriptome analysis showed 224,074 transcripts assembled clustering into 95, 832 unigenes, of which 21, 494 had ORF. RNA-seq analysis showed the highest number of differentially expressed genes on Day 9 at 15 ± 2 °C with 9291 genes (4772 up-regulated and 4519 down-regulated), recording the highest logarithmic fold change in pectin-related genes. Enrichment analysis presented significantly represented GO terms and KEGG pathways associated with molecular function, metabolic process, catalytic activity, biological process terms, as well as biosynthesis of secondary metabolites, plant hormone signal, starch, and sucrose metabolism, plant–pathogen interaction, plant–hormone signal transduction, and MAPK-signaling pathways, among others. Network analysis revealed that pectinesterase genes directly regulate the loss of firmness in fruits stored at 15 ± 2 °C