Abstract:

Effects of soil water on plant growth, contents and components of essential oil in fennel were studied , by controlling soil water content at low (relative water content, 44.46%±1.22%~52.84%±2.34%), middle (relative water content, 59.75%±3.11%~77.85%±3.47%) and high (relative water content, 75.24%±3.24%~99.27%±5.67%) levels. The results showed that, with increasing of soil water content , plant height, number of node, root and shoot fresh weight(FW), plant FW, content of total carbon, yield of essential oil per. plant and Chl.a/Chl.b ratio were elevated, but root/shoot ratio, contents of total nitrogen, proteinic nitrogen, Chl.a, Chl.b and CAR were decreased; Number of inflorescence, contents of essential oil and solubility sugar were higher in middle level water treatment, while they were lower in low and high level water treatments; Twenty-two chemical compounds were also identified in different soil water treatments, relative content was no difference (α=0.05) in α-Pinene, Sabinene, β-Pinene, γ-Terpinene, Terpinolen and Myristicin, but was significant ( α=0.05,0.01) in other sixteen compounds; With increasing water content , content of (E)-anethole, the dominant component in essential oil, was enhanced at 41.34%, 53.87% and 62.97%; Limonene was the second abundant material in oil, its content was decreased at 44.77%, 34.77% and 22.16%. This study indicated that lower water content had a positive role in accumulation of Limonene, and higher water content was relatively favour for storage of (E)-anethole in fennel.

Key words: fennel, water content of soil, growth, essential oil