Variations in the essential oil composition of persea bombycina (king ex Hook.f.) kost and its effect on muga silkworm (anteraea assama Ww)-a new report

摘要

Persea bomycina,with the local name 'Som',is a primary food plant for the 'muga' silk worm (Antheraea assama Ww).Hydrodistillation of the fresh green leaves of P.bombycina gives a clear and sweet scented oil in 0.02 to 0.054% (w/w) yield. Th eoil composition is investigated by GC and GC/MS.A total of 79 compounds have been identified.Substantial differences in the composition of the oils from 9 leaf samples are noticed.Aldehydes constitute a major portion of the oil (28.0 to 53.0%) followed by acids 911.4 to 40.8%) and alcohols (7.4 to 14.8%). Dodecanal (3.1 to 25.8%),decanal (2.4 to 25.8%),11-dodecenal (1.5 to 16.3%) and undecanal (1.3 to 9.5%) are present at extremely variable concentrations. Variations of (E)-nerolidol is quite conspicuous (0.5% to 21.9%).Out of the two oxides,caryophyllene oxide is a major component (3.0 to 12.1%). Experiments on rearing performances of muga silkworm on nine different collections of 'som',their most favoured host plant,reveal that grwoth of the worms are influenced unevenly by the diffeent chemcial constituents present in the essential oil. Correlation studies indicated that aldehyde per cent in the essential oil has positive influence on the growth of silkworm and cocoon quality,while increased acid per cent in the oilis fond to be derimetalfor growth and cocoon quality.