环境温度和湿度对尖孢镰刀菌侵染丹参幼苗的影响

Effects of temperature and humidity on infection of Fusarium oxysporum in seedlings of Salvia miltiorrhiza

枯萎病是栽培丹参的主要病害,其病原菌为尖孢镰刀菌,尖孢镰刀菌对栽培植物的侵染受到环境因素的影响。基于此,该文采用盆栽实验的方式研究尖孢镰刀菌对丹参幼苗侵染过程,揭示病害发生程度与植物体内病原菌浓度的关系,在此基础上研究环境温度和湿度对尖孢镰刀菌侵染丹参幼苗的影响。研究结果表明,丹参幼苗接种尖孢镰刀菌后,最先在栽种基质中检出,随着病原菌的不断繁殖,逐渐侵染至幼苗根和茎中(4~5 d),此时植株出现叶片黄化、萎蔫症状。7~8 d后在各部位中数量达到最大值,发病后期其在体内数量逐渐减少。随着丹参发病程度的加重,栽培基质、幼苗根和茎中病原菌的浓度呈现增加后下降的趋势,在中度发病的样本中尖孢镰刀菌浓度达到最大值,重度发病的样本中降低。另外,环境温度和湿度影响尖孢镰刀菌对丹参幼苗的侵染。尖孢镰刀菌对丹参幼苗侵染最适宜的环境温度为25~30℃,适宜的环境湿度为80%~90%。该研究对于今后开展丹参枯萎病病原菌的致病性实验、生防菌的筛选以及栽培丹参枯萎病的防治具有一定的指导意义。

Wilt disease is a major disease of cultivated Salvia miltiorrhiza,which is caused by Fusarium oxysporum.Since the infection process of F.oxysporum in plants is affected by environment factors,this study was conducted to reveal the relationship between disease severity and concentration of the pathogen in plants in the infection process of F.oxysporum in seedlings of S.miltiorrhiza by pot experiments and to reveal the effects of temperature and humidity on the infection process.The results showed that,after inoculation of S.miltiorrhiza seedlings with F.oxysporum,the pathogen in different parts was detected at different time,and it was first detected in substrates.With the continuous propagation of the pathogen(4-5 d),it gradually infected the roots and stems of the seedlings,and the plants had yellowing leaves and withering.The number of the pathogen reached the maximum in each part after 7-8 d,and then gradually decreased in the later stage of the disease.The concentration of the pathogen in substrates,roots and stems of S.miltiorrhiza showed a trend of decreasing after increasing with the aggravation of the disease and reached the maximum in the samples of moderate morbidity,while the concentration in the samples of severe morbidity decreased.In addition,the infection of F.oxysporum in seedlings of S.miltiorrhiza was affected by temperature and humidity.The suitable temperature was 25-30℃and the suitable humidity was 80%-90%.This study could provide guidance for the experiments on pathogenicity of F.oxysporum,screening of biocontrol bacteria and controlling of wilt.