Volatile compounds emitted in different phases of oak (Quercus robur) development (bark, unopened buds, young developing leaves, and blossoms) were analyzed with the aim of finding possible host-plant attractants for the European oak bark beetle, Scolytus intricatus. Complex mixtures of aliphatic, aromatic, and terpenoid compounds were identified in the samples. (E)-2-Hexenal and hexanal dominated in samples of bark. In buds, (Z)-3-hexenyl acetate formed a substantial part of the mixture. In both leaves and blossoms (E,E)--farnesene was the main component.
Volatiles released from oak twigs and branches during both the maturation feeding and construction of maternal galleries by Scolytus intricatus were also analyzed. Most compounds found in the samples from females’ and males’ maturation feeding were identical. High contents of anisole, (E)-β-ocimene, -copaene, one unidentified sesquiterpenic hydrocarbon C15H24 and β-caryophyllene were found in both samples of twigs attacked by beetles. During the construction of maternal galleries by bark beetles in oak logs, monoterpene hydrocarbons such as p-cymene, (E)-β-ocimene, and γ-terpinene, and sesquiterpenes -copaene and β-caryophyllene were released in large quantities. No new compound appeared when males were added to the log with feeding females. 相似文献
Summary Amino acid, polyamine and protein concentrations in seeds and their evolution during seed germination of two dipterocarp species, Hopea odorata and Dipterocarpus alatus, were determined with the help of a multianalytical system. Glutamic acid and glutamine were the major amino compounds present. Hopea seeds also contain high levels of aspartic acid/asparagine, serine, threonine, arginine and alanine, while those of Dipterocarpus contain high levels of alanine, arginine and threonine. These species were quite different in their germination behavior and thus in their protein and amine metabolism rates. In Hopea, polyamines increased during the first 3 days of germination and reached a maximum by the 3rd day, 1 day before maximum germination rate. In Dipterocarpus polyamines reached their maximum at the 6th day while maximum germination rate is observed by the 7th day. This suggests that polyamine compounds could play a role in the early part of the germination process in Hopea and Dipterocarpus seeds. The possibility that control of polyamine biosynthesis could be used for the establishment of biochemical methods to improve seed storage and to control germination of these recalcitrant seeds is discussed. 相似文献