Incidence and Distribution of Grapevine Leafroll-associated viruses in Tunisian Vineyards

Surveys were carried out in Tunisian table grape vineyards for assessing the occurrence and distribution of grapevine leafroll-associated viruses (GLRaVs). Leafroll symptoms were commonly observed in most of the surveyed vineyards. Samples were randomly collected from 712 individual vines for laboratory testing. Enzyme-linked immunosorbent assay (ELISA) tests showed that 81.5% of the vines were infected by one (35.7%) or more (45.8%) viruses. GLRaV-3 was the most widespread virus (76.3%), followed by GLRaV-5 (38.5 %), GLRaV-6 (13.2%), GLRaV-1 (9.1%), GLRaV-2 (6.3%), and GLRaV-7 (0.9%). GLRaV-3 and GLRaV–5, two mealybug-transmissible Ampeloviruses, were present in mixture in 35.9% of samples. The highest infection rate was found in Cape Bon region (81.7 %), where cv. Italia had an infection rate of 79.5%. Superior seedless, the main cultivar in Sidi Bouzid, had 75% infection. GLRaV-6 and -7 were detected for the first time in Tunisia.     

Reliability and validity of a new repeated agility test as a measure of anaerobic and explosive power

The aim of this study was to evaluate the reliability and validity of a repeated modified agility test (RMAT) to assess anaerobic power and explosiveness. Twenty-seven subjects (age: 20.2 ± 0.9 years, body mass: 66.1 ± 6.0 kg, height: 176 ± 6 cm, and body fat: 11.4 ± 2.6%) participated in this study. After familiarization, subjects completed the RMAT consisting of 10 × 20-m maximal running performances (moving in forward, lateral, and backward) with ~25-second recovery between each run. Ten subjects performed the RMAT twice separated by at least 48 hours to evaluate relative and absolute reliability and usefulness of the test. The criterion validity of the RMAT was determined by examining the relationship between RMAT indices and the Wingate anaerobic test (WAT) performances and both vertical and horizontal jumps. Reliability of the total time (TT) and peak time (PT) of the RMAT was very good, with intraclass correlation coefficient > 0.90 and SEM < 5% and low bias. The usefulness of TT and PT of the RMAT was rated as "good" and "OK," respectively. The TT of the RMAT had significant correlations with the WAT (peak power: r = -0.44; mean power: r = -0.72), vertical jumps (squat jump: r = -0.50; countermovement jump: r = -0.61; drop jump (DJ): r = -0.55; DJ with dominant leg: r = -0.72; DJ with nondominant leg: r = -0.53) and 5 jump test (r = -0.56). These findings suggest that the RMAT is a reliable and valid test for assessing anaerobic power and explosiveness in multisprint sport athletes. Consequently, the RMAT is an easily applied, inexpensive field test and can provide coaches and strength and conditioning professionals with relevant information concerning the choice and the efficacy of training programs.     

Evaluation of Antioxidant,Anticholinesterase, and Antidiabetic Potential of Dry Leaves and Stems in Tamarix aphylla Growing Wild in Tunisia

Tamarix aphylla (L.) Karst . has a wide geographic distribution and was employed in traditional medicine as astringent, anti‐rheumatic and to treat fever. T. aphylla leaves and stems extracts were studied from both chemical and biological points of view to assess the antidiabetic, anticholinesterase and antioxidant potential of this species. The HPLC/Diode Array Detector (DAD) analysis showed the presence of 14 phenolic compounds (gallic, caffeic, p‐coumaric, ferulic and ellagic acids, kaempferol, quercetin, quercetin 3‐O‐galactoside and six flavonol derivatives). This is the first study reporting a comparative study of the biological activities of different extracts from T. aphylla. High activities were obtained against DPPH radical, superoxide anion radical () and nitric oxide radical (^?NO) in a concentration‐dependent manner, the most active extracts being the polar ones. T. aphylla also showed moderate protective effects against acetylcholinesterase, but no effects were observed against butyrylcholinesterase. Against α‐glucosidase the MeOH extracts displayed IC₅₀ values from 8.41 to 24.81 μg/ml.