地黄块根膨大过程中土壤化感物质含量及微生物数量变化研究

以怀地黄为实验材料,对地黄块根膨大速率动态变化及地黄根际土壤中的潜在化感物质阿魏酸、香草酸、香草醛、对羟基苯甲酸含量的动态变化进行了研究分析.结果表明:①块根膨大速率动态变化呈一双峰曲线,第1个高峰出现在栽秧后70～130 d,第2个高峰出现在栽秧后150～190 d.②根际土壤中的阿魏酸、香草酸、香草醛含量变化与块根膨大速率变化动态相似,对羟基苯甲酸表现为先上升后下降;阿魏酸与地黄块根的膨大正相关;地黄块根膨大过程中根际土壤放线菌、真菌数量均明显增加,根际微生物可能将地黄根系分泌物进行生物转化生成了导致地黄连作障碍的酚酸类化感物质.

Changes of Phenolic Acid Content and Rhizosphere Microbial Population in Soil During Tuberous Root Expansion of Rehmannia glutinosa Libosch.

Using Rehmannia glutinosa Libosch.as materialsc,hanges of ferulic acid,vanillic acid,vanillin,phydroxybemoic acid,content in storage roots during the expansion stage of storage roots were studied.The main results are as follows:①The changing pattern of storage root expansion rate is a double-peak curve,the first peak appeared in 70～130 days after planting,and the second peak appeared at 150～190 days after planting.②The changing pattern of ferulic acidv,anillic acidv,anillic content in soil were similar to that of the storage root thickening rate.The content of phydroxybemoic acid rises in earlier stage then down in later stage.We analyzed number changes of rhizosphere microbial population in response to growth of Rehmannia glutinosa Libosch.It shows that actinomyces and fungus amount increase during the growth.Continuous cropping obstacle of Rehmannia glutinosa Libosch.cropping may resulted from phenolic acids produced by micro-community in rhizosphere from root exudates.