pH胁迫下尖孢镰刀菌生长动力学模型  

Growth kinetic model of Fusarium oxysporum under different pH

作　　者：蓝江林[1] 肖荣凤[1] 刘波[1] 朱育菁[1] 车建美[1] 林抗美[1] 

机构地区：[1]福建省农业科学院农业生物资源研究所,福州350003

出　　处：《中国生态农业学报》2012年第11期1532-1538,共7页Chinese Journal of Eco-Agriculture

基　　金：公益性行业科研专项经费项目(200903049)资助

摘　　要：尖孢镰刀菌（Fusarium oxysporum）是兼性寄生真菌,引起农作物枯萎病,防治困难。研究来自不同寄主的尖孢镰刀菌在不同pH马铃薯蔗糖（PS）琼脂培养基上的生长情况,构建动力学模型,以了解培养基的初始pH差异对尖孢镰刀菌生长特性的影响。测定了尖孢镰刀菌菌株在不同pH培养基、25℃培养条件下的生长速度,构建生长动力学模型。供试6个尖孢镰刀菌菌株在pH为3~10的液体培养基中均有不同程度生长,不同菌株对培养基pH的影响规律相似,在不同pH的PS液体培养基中培养14 d后,液体培养基的pH均有靠近6~7的趋势。在pH为3~9的培养条件下,尖孢镰刀菌菌落可以分成4类：菌丝型、粘滑层型、菌丝粘滑层型和菌丝带粉状物,各菌株的菌丝和培养基色泽也有所差异。同一菌株在培养基不同pH下生长速度不同,其生长的最适pH为6~8,菌落平均直径最大（45~49 mm）,亚适pH为4、5和9;而在pH为3、10和11时菌落直径明显变小（17~21 mm）。培养14 d后培养基pH对菌落形态、色泽有一定的影响,不同菌株在不同pH培养基培养下产孢量也存在差异。pH在4~8时其平均产孢量最大,达（223.8~273.3）×104cfu.mL 1,其中pH为6.38（自然pH）时产孢量最高,pH为11时产孢量最低。供试菌株在不同pH条件下的菌落生长速度和产孢量变化动力学模型均符合二次曲线方程。Fusarium wilt disease in agricultural crops caused by Fusarium oxysporum facultative fungi has always been difficult to control.In this paper,the effects of different pH on the growth characteristics of six F.oxysporum strains isolated from different host plants were studied by constructing a kinetic model with growth characteristics of F.oxysporum inoculated on potato sucrose（PS） agar mediums with different pH levels.The tested six F.oxysporum strains could grow in PS liquid medium with pH 3~9.pH changes of PS liquid medium with different stains was similar,closing to 6~7 after 14 days cultivation.This colony was divided into 4 categories（hyhae,stick-slip,hyhae and stick-slip,and hyhae with powdery types） in the range of pH 3~9.The hyhae and culture medium colors of the strains were different.F.oxysporum growth rate in different pH media was determined at 25 ℃,which was later used to build the kinetic growth model.Growth rate was affected by medium pH.The optimal growth（with maximum average colony diameter of 45~49 mm） was attained in the range of pH 6~8,followed by pH 4,5 and 9,with colony diameter significantly smaller（17~21 mm） at pH 3,10 and 11.Colony morphology and color were affected by media pH after 14 days cultivation.Differences existed among stain sporification at different pH,with the highest average sporification（223.8~273.3）×104cfu.mL 1 in the range of pH 4~8.Sporification was highest at pH 6.38（natural pH） and was lowest at pH 11.Strain colony growth and sporification at different pH were best depicted by quadratic equation.

关 键 词：PH胁迫 尖孢镰刀菌 生长动力学 菌落直径 产孢量 二次曲线方程 

分 类 号：Q945.1[生物学—植物学]