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In: Israel Journal of Plant Sciences

Abstract

Clinopodium serpyllifolium is a perennial medicinal plant generally used as herbal tea in folk medicine. Leaves of C. serpyllifolium from the representative exemplars in the Newe Ya’ar living germplasm collection were analyzed for their polyphenolic and volatiles composition, and tested for their antioxidant activity. The oxygenated monoterpenes pulegone (10.4–50.6%), piperitenone oxide (3.2–28.6%), piperitenone (0.9–14.6%), trans-piperitone oxide (0.3–11.2%), iso-menthol (0.3–8.8%) and sesquiterpene β-caryophyllene (7.4–13.7%) were found to be the major constituents from the solvent extraction of C. serpyllifolium analyzed by gc-ms. The representative exemplars were grouped into two chemotypes: one rich in pulegone and the second rich in piperitenone oxide and piperitenone. The total polyphenolics content, determined range from 26.6 to 62.9 mg gallic acid equivalents/g dry weight (dw). The antioxidant activity ranged from (42.8–77.1 mg chlorogenic acid equivalents/g dw). hplc analysis revealed the rosmarinic acid content also showed remarkable differences in C. serpyllifolium (0.3–1.8 dry weight %). The results indicate that there is chemical diversity and also difference in the content of polyphenols of the representative exemplars. Antioxidant activity was in correlation with phenolic components.

In: Israel Journal of Plant Sciences

Khat (Catha edulis Forsk., Celastraceae) is a perennial shrub that was introduced to Israel by Yemenite immigrants. Its young leaves are chewed for their psycho-stimulating properties. Young khat leaves contain the phenylpropylamino alkaloids (-)-cathinone [(S)-α-aminopropiophenone], (+)-cathine [(1S)(2S)-norpseudoephedrine], and (-)-norephedrine [(1R)(2S)-norephedrine] as the main active principles. A novel GC-MS analysis method for the quantitative determination of phenylpropylamino alkaloids and their putative biosynthetic precursor 1-phenylpropane-1,2- dione in khat leaves was developed. We utilized an alkaline-organic extraction, coupled with gas chromatography and a chiral permethylated beta cyclodextrin phase, to allow a full separation between the two diastereoisomers (1S)(2S)-cathine and (1R)(2 S)-norephedrine. We found a marked diversity in the phenylpropylamino alkaloid content and composition in three different locally grown accessions and the commercial cultivar ‘Mahanaim’.

In: Israel Journal of Plant Sciences

Bitter fennel (Foeniculum vulgare Mill. var. vulgare, Apiaceae) is a hemicryptophyte native to the Mediterranean basin and cultivated for its use as a medicinal and spice. We describe here the flowering dynamics and crossability among six native populations of bitter fennel collected from four localities in Israel, one from Sinai Desert (Egypt), and one from Mersin (Turkey) and grown from under agricultural conditions. Timing and duration of the stigma's receptivity were evaluated morphologically, enzymatically, and by determining fruit set in response to artificial pollination. Self-compatibility rates and crossability within and between populations were also determined in response to artificial pollination. Although the populations initiated flowering at different times through the season, in all cases the stigma's receptivity peaked between six and eight days after anthesis (yellow-bud stage) and lasted for seven days. Pollen can primarily germinate on the stigmata but the stylopodium serves too as a site for pollen germination, albeit at a lower efficiency (0-10% fruit set) as compared to stigmata (25-54%). Although there is complete dichogamy within flowers, umbels, and branches, there in not enough dichogamy between branches, and geitonogamy is therefore possible. Additionally, all populations displayed a high (0.7-3.7) index of self-compatibility (ISI), indicative of substantial self-pollination. Although interbreeding among populations was proven using artificial pollination, geographical isolation and the high likelihood for self-pollination probably restricts gene flow and contributes to the phenotypic diversity observed in wild fennel populations.

In: Israel Journal of Plant Sciences

Wild populations of Croatian clary sage (Salvia sclarea L.) were examined for variability to determine cultivation suitability in Croatia and Israel for breeding purposes. Phenotypic variability (coefficient of variation; %) was recorded for inflorescence weight (39.6%), inflorescence yield (52.8%), and essential oil yield (67.6%) when grown in Croatia. Associations were identified between inflorescence yield and essential oil yield (r = 0.9; P < 0.0001), inflorescence weight and inflorescence yield (r = 0.8; P < 0.0001), and inflorescence weight and inflorescence length (r = 0.6; P = 0.0056), suggesting that populations with elongated inflorescence are indirectly associated with higher essential oil yield. In Israel, the populations reached full bloom between the end of May and early June, corresponding on average to 397.5 days post planting. Linalyl acetate, linalool, α–terpineol, sclareol, and geranyl acetate were the leading essential oil components in both Croatia and Israel. The principal compounds in the oil were linalyl acetate (48.5%) and linalool (17.7%), signifying that the Croatian populations were of the linalool chemotype. A two-way ANOVA indicated an interaction between growing location (Croatia vs. Israel) and population for linalool (P = 0.02), α–terpineol (P = 0.007), and linalyl acetate (P = 0.09); evidence of an environmental effect on essential oil composition. The variation observed suggested that the wild population of clary sage in Croatia had the genetic heterogeneity essential for breeding. Nevertheless, the differences in essential oil composition between Croatia and Israel suggest that breeding efforts should be separately focused for each agriculture production system.

In: Israel Journal of Plant Sciences

The antioxidative properties of forty-seven plant samples originating from the Ein Gedi Botanical Garden were screened. Their antioxidative activity, determined by DPPH radical scavenging assay and expressed as chlorogenic acid equivalent, ranged from 0.3 to 88 mg/g DW. The total phenol content, determined by the Folin-Ciocalteu assay, ranged from 2-82 mg/g DW. A substantial correlation was found between the antioxidative activity and the total phenol content among species. Tamarix nilotica, Suaeda vera, Acacia raddiana, Lawsonia alba, and Grewia villosa contained the highest antioxidative properties. This work consists of the first screening of the antioxidative properties of indigenous plants from the Dead Sea area. The future introduction of these plants as agricultural crops may provide novel natural sources for antioxidants.

In: Israel Journal of Plant Sciences

Ocimum spp. are cultivated worldwide for culinary and medicinal uses. Some species are the subjects of improvement in breeding programs while others are still collected from the wild. Polyploidy and dysploidy are common features of the cultivated species. Taxonomical confusion has arisen in the classification of Ocimum spp., in part due to the ease with which many of the species intercross and the morphological similarities between several of the species. Flow cytometry is a fast and easy method to measure nuclear DNA content and could be a useful tool to assess germplasm accessions in a breeding program. Here we report the first estimates of nuclear DNA content of eight Ocimum spp., as determined by flow cytometry. The 2C nuclear DNA content ranged from 928 (O. campechianum) to 5515 Mbp (O. americanum). The nuclear DNA content levels may be useful for better understanding of the taxonomical relationships among species.

In: Israel Journal of Plant Sciences