Growth and developmental responses of spinach (Spinacia oleracea L.) to the decomposing leaf litter of blue gum (Eucalyptus maidenii F. Muell.)

摘要

We investigated the allelopathic effects of decomposing leaf litter of blue gum {Eucalyptus maidenii F. Muell.) on the growth and development of spinach {Spinacia oleracea L.). Gas chromatography-mass spectrometry (GC-MS) was used to identify and compare volatile compounds in the original leaf litter and decomposed leaf litter. No significant differences were observed in leaf number of spinach between random leaf litter treatment and the control at vegetative stage (p > 0.05). However in reproductivestage, the responses of two sexual types were different to leaf litter decomposition in terms of some morphological, physiological and phenological traits. The sex ratio (F/M) was increased by 60 g but reduced by 120 g leaf litter for both years. Seventy-nine volatile compounds were identified from the original leaf litter sample and after 4-months of decomposition, the volatile compounds decreased sharply in diversity and absolute peak area. Of the majority of 52 terpenes, alpha-pinene, aromadendrene,eucalyptol and eudesmol were optimal caused the allelopathic effects.