酸雨与凋落物复合作用对柳杉种子萌发与幼苗生长的影响

采用培养皿法研究了不同pH值模拟酸雨、柳杉Cryptomeria fortunei凋落物水浸提液和酸雨浸提液对柳杉种子萌发和幼苗生长的影响,并采用气相色谱-质谱(GC-MS)联用技术对柳杉凋落物水浸提液和酸雨浸提液的化学成分进行了分析。结果表明:①酸雨和凋落物水浸提液处理均降低柳杉种子发芽率和发芽势,凋落物酸雨浸提液处理柳杉种子发芽率和发芽势与对照差异显著(P0.05),说明酸雨增强了凋落物对柳杉种子萌发的抑制作用。②酸雨处理抑制柳杉幼苗根生长和根芽比,而pH 3.0处理芽生长和生物量则显著减小(P0.05);50 g·L-1凋落物水浸提液处理对柳杉幼苗芽和根的生长,以及生物量和根芽比具有显著的抑制作用(P0.05),凋落物酸雨浸提液处理抑制作用呈极显著差异(P0.01)。③GC-MS分析显示,柳杉凋落物水浸提液和酸雨浸提液的主要成分是醇类、酚类、烷烯类和酯类等化合物,占总量的86.1%,凋落物酸雨浸提液中鉴定出新的化合物包括4种酮类化合物和2个醇类,占总量的2.6%。图4表1参30

Combined effects of acid rain and litter on seed germination and seedling growth of Cryptomeria fortunei

Abstract: In order to understand the combined effects of acid rain and litter on the growth of Cryptomeria fortunei，we studied the effects of the acid rain, aquatic extract and acid rain extracts from litter on the seed germination and seedling growth of C. fortunei by using petri dishes culture method，and analyzed the chemical components of the extracts using GC-MS. Results showed that：（1） Both simulated acid rain and aquatic extracts reduced the seed germination rate and germination potential of C. fortunei. Under the effects of acid rain extracts the seed germination rate and germination potential were significantly different from the controlled ones （P＜0.05）. It is indicated that acid rain enhanced the inhibition effect of allelochemicals from C. fortunei litter on its seed germination. （2） Acid rain declined the ratios of root to bud and root growth of C. fortunei. And acid rain（pH 3.0） significantly reduced the bud growth and biomass（P＜0.05）. At 50 g·L^-1 the aquatic extracts significantly declined the root and bud growth，biomass and the ratios of root to bud（P＜0.05）. The growth indicators are significantly different from effects of acid rain extracts with the controlled ones（P＜0.01）. （3） 42 secondary metabolic compounds were identified in the aquatic litter extract of C. fortunei. The major compounds of the aquatic litter extracts and acid rain litter extracts were alcohols，phenolics，betweenanenes and esters, which all together accounted for 86.1% of the total. And in acid rain extracts，of which the newly released compounds including 4 ketones and two alcohols, accounted for 2.6% of the total.［Ch，4 fig. 1 tab. 30 ref.］