绛红褐链霉菌的根际定殖能力动态监测

Dynamic detection for colonization of Streptomyces purpeofuscus in Juglans sigllata rhizosphere

腐皮镰刀菌(Fusarium solani)是铁核桃(Juglans sigllata Dode)根腐病的重要致病菌,绛红褐链霉菌YSSPG3(Streptomyces purpeofuscus)对其具有较强的拮抗作用。为了监测该生防菌在根际土壤中的定殖动态及在其作用下病原菌(F.solani)的动态变化,以盆栽铁核桃为研究对象,研究了S.purpeofuscus对接种F.solani植株的生防效果,并用实时荧光定量PCR技术分别对生防菌S.purpeofuscus和病原菌F.solani在铁核桃根际土壤中动态变化进行研究。结果表明,S.purpeofuscus对病原菌F.solani有较为明显的生防效果。监测结果表明:接种短期内S.purpeofuscus迅速生长繁殖,20 d其相对表达量达到最高值,随后呈下降趋势,40 d后趋于稳定;接种S.purpeofuscus后,F.solani的相对生长量显著下降,60 d时降低了11 500%,进一步表明S.purpeofuscus对F.solani生防效果显著,可以作为铁核桃根腐病的前景生防菌。

Fusarium solani is an important pathogen on Juglans sigllata causing root rot,which can be strongly antagonistic by the strain Streptomyces purpeofuscus YSSPG3. In order to monitor the colonization dynamics of S. purpeofuscus on rhizosphere soil and the dynamic variation of F. solani,the same infectious indices of J. sigllata were studied as the research objects. Based on inoculating S. purpeofuscus to the pathogenetic plants,the dynamic changes of S. purpeofuscus and F. solaniin rhizosphere soil was investigated by real-time fluorescence quantitative PCR,and the dynamic colonization detection system of S. purpeofuscus and the dynamic change system of fungus were established respectively. The results showed that the strain S. purpeofuscus YSSPG3 could multiplied rapidly in a short time after inoculation,the strain peaked on the 20 th day and then declined until the 40 th day,finally,it kept stable. On the 60 th day,the relatively expression quantity of F. solani roped nearly 11 500%,which showed significantly biocontrol effects on F. solani. The study provided a reliable technical support on the real-time monitoring of plant diseases caused by F. solani,it also layed an important theoretical foundation on the colonization detection of S. purpeofuscus in rhizosphere.