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.
Characterization of the Insect Assemblage and Associated Floral Volatiles of Black Cherry (Prunus serotina)
Black cherry is an ecologically important high-value wood. A decline of its regeneration has been reported in the USA, which could be associated with a lack of pollination. This study was conducted to identify insects visiting black cherry flowers, to determine whether insects captured on the flowers carry black cherry pollen and to identify the volatile organic compounds (VOCs) emitted by flowers of black cherry. A two-year insect survey was conducted before, during and after the black cherry bloom. A total of 9533 insects were captured in traps and Diptera was the most abundant (64.1%). Significantly more insects in Diptera, Lepidoptera and Thysanoptera were captured in the traps installed in the canopy than those on the ground, and Anthalia bulbosa (Diptera: Hybotidae) was the dominant species. Electron microscopy analyses demonstrated that insects captured in the canopy indeed carried black cherry pollen. Black cherry flowers emitted a VOC blend that is composed of 34 compounds and dominated by β-ocimene and several phenylpropanoids/benzenoids. This floral VOC profile is similar to that of other pollinator-dependent Prunus species. This study reports pollinator insects and associated VOCs, for the first time, that could play a significant role in the pollination and regeneration of black cherry.
Investigations on the rôle of organic matter in plant nutrition
1. As the result of decomposition of green manure in a swamp soil, the coarse fractions (including coarse and fine sand) of the surface layer (first 3 inches) decreased by 11·2 per cent. while the fine ones (silt+clay) increased by 9·8 per cent. in the course of 43 days. The effect was less pronounced in the manured soil maintained at 60 per cent. saturation, while no alteration was to be noticed in the case of the unmanured specimens. 2. Treatment with dilute hydrochloric acid prior to dispersion had no appreciable effect on the estimates of mechanical composition obtained in the different cases. Loss in solution was also comparatively small. 3. The silica-sesquioxide ratio increased slightly as the result of decomposition of green manure in swamp soil. The composition of the fine fractions was also altered, the total percentages of the oxides of iron, aluminium and silicon increasing from 90·5 to 99·3 in the course of 71 days. 4. The practical significance of the above and related observations has been discussed.