Rapid Determination of Volatile Constituents from the Buds and Flowers of Prunus Persica (L.) Batsch. f. duplex Rehd
The head-space (HS) volatile compounds of the buds and flowers of Prunus persica (L.) Batsch. f. duplex Rehd were analysed by solid-phase microextraction (SPME) coupled with capillary gas chromatography/mass spectrometry (GC-MS). Typical compounds detected in P. persica (L.) Batsch. f. duplex Rehd buds and flowers were alkanes. Tetradecane (4.07%), 4,8- dimethyl undecane (4.56%), pentadecane (11.3%) and hexadecane (4.62%) were identified as the main compounds in the buds, and tricosane (20.03%) , hexadecane (3.34%) were detected in the flowers as the main alkanes. On the other hand, (Z)-octadec-9-enoic acid (20.94%) was found in the buds as the main compounds.
Sea Buckthorn: New Crop Opportunity
Sea buckthorn (Hippophae rhamnoides L., Elaeagnaceae) is a winter hardy, deciduous shrub with yellow or orange berries (Bailey and Bailey 1978). It develops an extensive root system rapidly and is therefore an ideal plant for preventing soil erosion and land reclamation. It can withstand temperatures from –43° to 40°C (Lu 1992). It is considered to be drought resistant (Heinze and Fiedler 1981); however, irrigation is needed in regions receiving <400 mm of rainfall per year for better growth (Li and Schroeder 1996).
Inhibition of Root Growth and Polyamine Metabolism in Sunflower (Helianthus annuus) Seedlings Under Cadmium and Copper Stress
Although sunflower is usually regarded as a highly tolerant crop, impairment of root growth at initial stages of plant development may result in poor crop establishment and higher susceptibility to pathogen attack. In order to evaluate if Cd2+ and Cu2+ may impact on sunflower germination and initial root development, a pot experiment under controlled conditions was carried out. Possible involvement of polyamine metabolism in sunflower response to these stressors was also investigated. Although Cd2+ and Cu2+ treatments affect neither seed germination nor radicle emergence, sunflower seedlings grown in the presence of these heavy metals showed significant inhibition of root growth, being this inhibition greater for Cd2+. Both metals caused significant increases in proline contents at the highest concentrations tested (0.5 and 1 mM), and these increments were more pronounced for Cd2+ treatments, especially between days 3 and 10. Metals also increased putrescine (Put) contents at all concentrations assayed from the seventh day onward, causing no variations on this polyamine time-course pattern. Spermine and spermidine contents, however, were increased only by 1 mM Cd2+. Arginine decarboxylase seems to have been the enzyme responsible for Put increases under both metal treatments. This work demonstrates that initial root growth of sunflower seedlings may be significantly impaired in Cd2+ or Cu2+ contaminated soils. It also shows that polyamines are key biological compounds, which are probably involved in signaling pathways triggered under stress environmental conditions.