植物提取物、碳酸钠和碳酸氢钠室内对杨树溃疡病菌生长的抑制作用

 采用菌丝生长速率法用金银花的花、黄花蒿的地上部分、蓝桉果实和黄柏果实的乙醇提取物及其不同极性的组分对杨树溃疡病菌菌丝生长的抑制作用进行了测定。以黄柏果实的抗菌活性最强,其次是金银花的花。抗菌活性成分主要存在于金银花的正丁醇组分、黄花蒿的石油醚组分和乙酸乙酯组分、蓝桉的水部分、黄柏的正丁醇组分。当培养基中碳酸钠和碳酸氢钠的浓度分别为8g/L时(对应的pH值分别为10.24和7.71),菌丝生长抑制率分别为100.00%和79.68%。如果用1mol/L氢氧化钠溶液调节培养基的pH值至10.00,菌丝生长抑制率为40.58%。说明碳酸钠或碳酸氢钠对菌丝生长的抑制作用,一方面是由于改变了培养基的pH值,另一方面可能是由于碳酸根和碳酸氢根离子抑制了菌丝的生长。

Inhibition of plant extracts, sodium carbonate and sodium bicarbonate on the pathogen of poplar canker Botryosphaeria dothidea

Four medicinal plants Lonicera japonica,Artemisia annua,Eucalyptus globulus and Phellodendron chinense were screened in vitro for their antifungal activities on poplar canker pathogen Botryosphaeria dothidea(anamorph: Dothiorella gregaria) by using mycelial growth method.Ethanol extracts as well as fractions with different polar components were prepared from L.japonica flower,the aerial part of A.annua,E.globulus fruit,and P.chinense fruit separately.Among them,P.chinense was found to have the strongest inhibitory activity,then was L.japonica.Antifungal components were existed mainly in n-butanol fraction of L.japonica,petroleum ether fraction and ethyl acetate fraction of A.annua,water fraction of E.globulus,and n-butanol fraction of P.chinense.Inhibiting effect of sodium carbonate and sodium bicarbonate against the mycelial growth were 100.00% and 79.68% separately at the concentration of 8 g/L in medium with pH 10.24 and 7.71 respectively.When pH was adjusted to 10.00 using 1.00 mol/L of sodium hydroxide,the inhibition rate of mycelial growth was only 40.58% which was much smaller than that of sodium carbonate adjustment.It indicated that mycelial growth inhibition was resulted from both pH in medium and carbonic acid ions.