Biocontrol of Wheat Leaf Rust Caused by Puccinia Triticina and Induction of Systemic Acquired Resistance by Salicylic Acid
|School||Agricultural University of Hebei|
|Keywords||Wheat leaf rust Biological Control Endophytic bacteria Streptomyces Salicylic acid|
By wheat leaf rust caused by wheat leaf rust (Puccinia triticina Eriks.) Is the most widely distributed in the world, is one of the main diseases in wheat production. In order to effectively control the disease, the test screening biocontrol strains of wheat leaf rust, effective method of control of wheat leaf rust. In this paper, spore germination inhibition assay and indoor control experiment of wheat leaf rust prevention effect. 1 wheat leaf rust screening of biocontrol strains isolated from plants five endophytic bacteria (CN015r, CN017r, CN078, CN180, SH), JM218 and WCS417r 2 rhizobacteria, the WCS358 2 transgenic strains (WCS358 :: phl WCS358 :: phz) and Streptomyces rimosus (CN124) and Streptomyces (CN182) 11 strains as the test fungus Puccinia triticina urediniospores germination inhibition test, seven pairs of spores germination preferably inhibition strains were screened for effective strain to mark its rifampicin-resistant mutant strains, formulated as a certain concentration of bacterial suspensions, using two methods of soaking and spray on wheat leaf rust indoor prevention and treatment trials. The results showed that, after soaking treatment, CN180r strains of wheat leaf rust has significant control effect, the severity of the disease decreased by 50.2% compared with the control. Spray treatment, CN124 wheat leaf rust prevention effect significant 71.1% decline in the incidence of the disease. CN180 sequencing molecular identification in NCBI BLAST alignment number EU761590.1 strains up to 97% similarity, orange Pseudomonas (Pseudomonas aurantiaca) bacteria colonization in wheat vivo can also reach the surface of the wheat. 2 wheat endogenous bacteria to control wheat leaf rust susceptible varieties 5389 MS Miao isolated from wheat six endophytic bacteria, endogenous bacterial spore germination test, then the endogenous bacterial preparation of a certain concentration of bacterial suspension, soaking and spray two methods, indoor wheat leaf rust prevention test. The results showed that, after soaking treatment, CN181 has better control effect of wheat leaf rust prevention, its incidence and severity are and control the formation of significant differences in the level. Tested CN181 strains of Gram-positive bacteria, molecular identification results CN181 strains of No. similar DQ520955.1 strains up to 99%, Bacillus subtilis (Bacillus subtilis). The first time the wheat leaf rust preventive effect of endogenous bacterial strains. SA-induced wheat resistance to wheat leaf rust wheat leaf rust urediniospores germination inhibition test using different concentrations of salicylic acid, the summer spore germination was not obvious, the inhibitory effect of 5.0 mM. Different concentrations of salicylic acid on wheat leaf rust the indoor control experiment, the SA concentration of 2.0 mM when the induced effect of the wheat leaf rust best, can reach more than 40% in the spray treatment. SA concentration of 5.0 mM when the induction effect in the leaching root processing Preferably, more than 30%. 2.0 mM SA and 5.0 mM, respectively spray test and drench the root process to determine the most appropriate role of time in SA, salicylic acid spray treatment and drench the root process, were inoculated wheat leaf rust 5 d The incidence and severity of leaf rust minimum. Provide a basis for the use of salicylic acid to control wheat leaf rust.