Antioxidant Properties and Evaluation of Phytochemical Composition of Salvia verbenaca L. Extracts at Different Developmental Stages

Changes in the contents and composition of polyphenolics and resulting antioxidant activities of S. verbenaca by-products were investigated at three phenological stages (flowering, early fruiting and late fruiting stages). The highest accumulation of total phenolics was detected at the flowering stage (58.36 mg GAE/g DW). HPLC analysis of methanolic extracts showed the prevalence of methyl carnosate (821.45–919.82 μg/g DW) and rosmarinic acid (544.51–649.26 μg/g DW). Phenolic diterpenes (1056.90–1148.42 μg/g DW) was the most represented class of compounds. Three complementary tests namely, DPPH^? (IC₅₀ value, 49.22 μg/mL) and ABTS^?+-radical scavenging assays (146.86 μM TE/mg) and FRAP reducing power test (188.93 mM Fe(II)/mg) were used to evaluate the antioxidant capacity and showed the best performance at the early fruiting period. The current study evidenced the significant effect of phenophase on antioxidants and contributed to valorize S. verbenaca extracts as a source of functional phenolic compounds.

     

The inhibitory effects of Gelam honey and its extracts on nitric oxide and prostaglandin E2 in inflammatory tissues

We investigated the effects of honey and its methanol and ethyl acetate extracts on inflammation in animal models. Rats’ paws were induced with carrageenan in the non-immune inflammatory and nociceptive model, and lipopolysaccharide (LPS) in the immune inflammatory model. Honey and its extracts were able to inhibit edema and pain in inflammatory tissues as well as showing potent inhibitory activities against NO and PGE₂ in both models. The decrease in edema and pain correlates with the inhibition of NO and PGE₂. Phenolic compounds have been implicated in the inhibitory activities. Honey is potentially useful in the treatment of inflammatory conditions.     

Validation of simple sequence repeats associated with quality traits in durum wheat

Over recent years, quality has become an important commercial issue for durum wheat breeders. Modern breeding methods are most efficient for producing and supplying the best quality raw materials to the pasta industry. Here we assessed the effectiveness of molecular marker-assisted selection of quality traits in durum wheat. To this end, DNA and quality trait markers were jointly used to analyze quality-related traits in a durum wheat collection. A total of 132 durum wheat (Triticum turgidum ssp. durum) Mediterranean landraces, international lines, and Moroccan cultivars were analyzed for seven important qualityrelated traits including thousand-kernel weight (TKW), test weight (TW), gluten strength, yellow pigment (YP), and grain protein content (GPC). Additionally, 18 simple sequence repeat (SSR) markers previously reported to be associated with different quality traits were analyzed. Of these, 14 (78%) were polymorphic and four were monomorphic. There were between two and seven alleles per locus, with an average of four alleles per locus. The average phenotypic variation value (R²) ranged from 2.81 to 20.43%. Association analysis identified nine markers significantly associated with TKW, TW, and YP, followed by eight markers associated with GPC, six markers associated with yellow index b, four markers associated with brightness L, and three markers associated with SDS-sedimentation volume. This study highlights the efficiency of SSR technology, which holds promise for a wide range of applications in marker-assisted wheat breeding programs.     

Effects of growing region and maturity stages on oil yield and fatty acid composition of coriander (Coriandrum sativum L.) fruit

Changes on oil yield and fatty acid profiles were studied during maturation of coriander (Coriandrum sativum L.) fruits cultivated in Menzel Temime and Oued Beja, Tunisia. Oil and petroselinic acid biosynthesis proceeded at a steady rate up to 16 DAF in Oued Beja and in 33 DAF in Menzel Temime. The first results show that a rapid oil accumulation started at newly formed fruits and continued until their full maturity. During fruit maturation, fatty acid profiles varied significantly among the growing regions and stages of maturity. Petroselinic acid had the highest amount at the 16th and the 33th DAF, in Oued Beja and Menzel Temime, respectively. In Oued Beja, at full maturity, the main fatty acids were petroselinic acid (80.90 ± 9.45%), followed by oleic (14.79 ± 2.25%), palmitic (3.50 ± 0.65%) and stearic (0.49 ± 0.09%) acids. Fatty acid profile of fruits cultivated in Menzel Temime showed that in fully ripe fruit, petroselinic acid is the main compound (80.86 ± 7.23%) followed by oleic (14.83 ± 2.05%), palmitic (3.27 ± 3.12%) and stearic (0.31 ± 0.05%) acids. In both growing region, fruit development resulted mainly in an increase of petroselinic acid and a decrease of palmitic acid. Saturated and polyunsaturated fatty acids decreased significantly and monounsaturated fatty acids increased during maturation of fruit. Oil composition at the first four stages of maturity has a healthy and nutritionally value and the last stages were with important economic and industrial applications. Coriander fruit is potentially an important source of petroselinic which have numerous industrial applications.     

Water relations of olive trees cultivated under deficit irrigation regimes

The experiment was carried out at the Experimental Field ‘Taoues’, southern Tunisia (34°N, 10°E) to examine the effect of irrigation schedules on water relations for young olive trees, cultivars Chétoui, Chemlali, Coratina, Picholine and Manzanille. Plants were cultivated at 7 m × 7 m spacing and drip irrigated from April to September. Irrigation amounts (IA) of 20%ET_c, 50%ET_c and 100%ET_c were applied, where ET_c is the FAO crop evapotranspiration. The effect of IA on midday leaf water potential (Ψ_leaf), stomatal resistance (R_s) and conductance (g_s), soil (H_v) and relative leaf (RWC) water contents was studied. Results showed that a further increase in IA was not systematically followed by an increase of water potential, production and WUE values. Some controversial responses were observed following to a variety with large seasonal variations. At the beginning of the growing season, differences between treatments were not very important because soil water content was still high enough to prevent important changes in Ψ_leaf values. The most stressed trees showed potentials of −1.53 MPa for Picholine cv. and ranging between −2.30 MPa and −2.10 MPa for the other varieties depending on IA. The less stressed trees provided potentials of −0.97 MPa for Picholine cv. and varying between −1.63 MPa and −2.13 MPa for cultivars Coratina, Manzanille, Chétoui and Chemlali. Then, as the season progresses, and when IA was increased from 20%ET_c to 50%ET_c, Ψ_leaf values decreased significantly for cultivars Chemlali (−3.05 MPa), Coratina (−3.75 MPa), Manzanille (−3.0 MPa) and Chétoui (−3.5 MPa). At 100%ET_c, Manzanille and Picholine cultivars show better water status with respective potentials of −2.7 MPa and −2.6 MPa. Stomatal resistance monitoring showed maximums at midday for all cultivars with pick value of 4.45 s/cm recorded for Chétoui cultivar irrigated at 50% ET_c. The most important variations were recorded for cultivar Chemlali which seem to be the ablest to regulate stomata aperture. Close coordination between Ψ_leaf and g_s and Ψ_leaf and RWC measurements was found. But, the response varied following to treatment. At low irrigation levels (20%ET_c and 50%ET_c), g_s was found to be linearly and positively correlated to Ψ_leaf. It increased linearly and positively with increasing values of Ψ_leaf (r of 0.84 and 0.96, respectively). At 100%ET_c, Ψ_leaf is found to be correlated to g_s following to a polynomial function with an optimum g_s value of 450 mmol/m²/s and Ψ_leaf of about −2.5 MPa.     

Development of zygotic and somatic embryos of Phoenix dactylifera L. cv. Deglet Nour: Comparative study

In order to improve somatic embryogenesis production in date palm Phoenix dactilyfera L. cv. Deglet Nour (DN), a comparative study between somatic (SE) and zygotic (ZE) embryos developments was carried out. The data showed that ZE maturation occurred from 10 to 19 weeks after pollination (WAP). During this period, the fresh weight (FW) and the dry weight (DW) of ZE increased progressively to reach a maximum level at 19 WAP. SE development occurred in three distinct stages. The DW remained constant during the two first stages, and declined slightly during the third and final stage. Embryo protein analysis revealed significant differences between ZE and SE. The ZE total protein level was initially low and increased to the maximum at mature stage. However, no significant change in total protein was detected during SE development. SDS-PAGE analysis showed a poor protein profile for SE, compared to that of ZE. In the latter, a 22 kDa protein was identified by N-terminal sequencing as a glutelin. This protein was accumulated rapidly during early development and remained at a relatively constant level during ZE development, and then declined progressively 12 days after embryo germination (DG). This protein seems to be absent in SE.     

Morphological,Physiological, and Biochemical Responses to Water Stress in Melon (Cucumis melo) Subjected to Regulated Deficit Irrigation (RDI) and Partial Rootzone Drying (PRD)

Journal of Crop Science and Biotechnology - In this study, the impact of two water-saving techniques, Regulated Deficit Irrigation (RDI) and Partial Rootzone Drying (PRD) was investigated by...     

Effect of foliar bio-fertilization on growth and biochemical parameters of olive trees at flowering

Growth and biochemical parameters of leaves, flower buds and flowers of olive (Olea europaea L. cv. Chemlali) treated by foliar biofertilization (T0: untreated trees; T1: rich in nitrogen (N), phosphorus (P), potassium (K); T2: rich in calcium (Ca); T3: application of T1 and T2) were analyzed during the flowering stage. The results showed that T1 resulted in higher contents of leaf N, K, and Na. T1 and T3 resulted in an increase of pigment concentration in leaves. All foliar treatments affected negatively the contents of total polyphenols and orthodiphenols in leaves and flower buds. Lower amounts of individual phenolic compounds were detected in the leaves under all foliar bio-fertilizations and in flower buds of olive trees sprayed with T2 and T3. This decrease is explained by the lower enzymatic activity of l-phenylalanine ammonia-lyase. In flowers, T1 exhibits the highest levels of total polyphenols, o-diphenols, and individual phenolic compounds compared to T0.