NaCl胁迫下苯丙烯酸对黄瓜幼苗根际土壤微生物及产量的影响

Effects of Cinnamic Acid on Micro-organisms and Yield of Cucumber Seedlings under NaCl Stress

实验以耐盐的津绿5号和盐敏感的津优1号黄瓜品种为试材,以NaCl(585 mg kg-1)为盐胁迫条件,研究了盐胁迫下不同浓度的苯丙烯酸(0、25、50、200 mg kg-1)对黄瓜幼苗根际土壤微生物及产量的影响。结果表明,盐胁迫处理降低了黄瓜幼苗土壤根际细菌、真菌、放线菌的数量,而对镰孢菌数量有促进作用,并降低了黄瓜产量。低浓度的苯丙烯酸对黄瓜幼苗土壤根际细菌、真菌、放线菌的数量具有促进作用,对镰孢菌有抑制作用,对盐胁迫有一定的缓解作用,并对黄瓜产量具有促进作用;高浓度苯丙烯酸(200 mg kg-1)则相反,进一步加重了盐害的胁迫程度,抑制了黄瓜产量。盐胁迫对细菌、真菌、放线菌和镰孢菌数量的影响强度大于苯丙烯酸,而苯丙烯酸对细菌群落DGGE条带数和黄瓜产量的影响强度大于盐分胁迫。

Salt-tolerant cucumber cultivar（Jinyou No.5） and salt-sensitive cucumber cultivar（Jinyou No.1） were used as materials,and NaCl（585 mg kg^-1） as the salt-stress condition,the effects of different concentrations of cinnamic acid（0,25,50,200 mg kg^-1） under salt stress condition on cucumber seedlings growth and rhizosphere soil enzymes activities were studied.Results showed that salt-stress treatment reduced the biomass of soil bacteria,epiphyte and actinomyces but increased the quantify of fusarium in the cucumber rhizosphere.Salt-stress treatment also reduced the yield of cucumber.Low concentration of cinnamic acid（25 mg kg^-1） had stimulating effects on soil bacteria,epiphyte,actinomyces quantities but inhibited the fusarium growth,and it also lessened the salt-stress.High concentrations of cinnamic acid（200 mg kg^-1） had the opposite effects on the above parameters and worsened the salt-stress and reduced the yield of cucumber.Salt-stress had greater effects on the quantities of bacteria,fungi,actinomycetes and fusarium than cinnamic acid.While cinnamic acid had greater effects on bacterial DGGE bands and yield of cucumber than salt stress.