Pathogen Isolation And Biological Control Of Wheat Root Rot In Hebei Province

Hebei is one of the major wheat producing provinces in China.Wheat root rot is the most serious disease of three major diseases that harm wheat production.In order to clarify the extent of wheat root rot in Hebei Province,the wheat of 19 regions were investigated and analyzed in Hebei province,and the pathogen were isolated and identified.The wheat root rot strain isolated from the samples were identified whether possess the pathologies differentiation by stabbed inoculation method,and is there a correlation between the differentiation phenomenon and the growth period,geographical origin,and colony color.In addition,the resistance to wheat root rot of wheat cultivar in Hebei province were identified using the soil-infected method and the biological control strains were screened for effective controlling the wheat root rot through the field efficacy trails.This research aims to provide the theoretical support and science methods for the integrated controlling the wheat root rot,and to improve the program for resistance breeding.The main results are as follows:1.By investigating the disease index of wheat root rot around the country,it was found that the occurrence of wheat root rot occurred in Hebei Province,the degree of disease was different.The disease index at seedling stage was 7.20 to 43.76,and the disease index at adult stage was 9.54 to 62.27.2.A total of 1951 tissue blocks were isolated from wheat root rot samples collected from 19 cities in Hebei Province,and the isolation rate was 77%.Among them,Bipolaris sorokiniana are dominant strains and accounted for 30.92% of the total isolates.The Alternaria tenuissima,Rhizoctonia solani,Rhizoctonia,Fusarium graminearum,Fusarium oxysporum,Fusarium proliferatum,Fusarium acuminate,Fusarium oleracea accounted for 6.88%,11.66%,3.08%,8.75%,18.28%,12.70%,3.36%,3.04% of the total isolates,respectively.3.The 40 representative isolates were pathogenic,and the pathologies was different.The DB-5 strain had the longest average lesion length of 2.56 cm,while the HZ-16 strain had the smallest lesion,only 0.73 cm.The analysis of significance level showed that the pathologies of 40 strains are different and there is a virulence differentiation phenomenon.The virulence is no obvious correlation with the growth period and geographical origin,but correlated with the colors of the colonies according the clustering results.4.Through the identification of resistance,wheat varieties resistance to wheat root rot is poor in Hebei Province,There are no immune variety and there are significant differences to wheat root rot between varieties.Kenong2009 is a resistant variety,accounting for 1.80% of the tested varieties;Jimai 22,Shannong 20,Guan 35,Shijiazhuang 8 and Zhoumai 22 is moderately resistant varieties,accounting for 8.90%,susceptible and high susceptible varieties accounted for 89.30%.5.The three biological control bacteria strains S-1,S-19 and S-4,were screened with better antibacterial and control effect on wheat root rot,in the plot and fields.It is found that the control effect of S-1 at the seedling stage was 65.76%,and the control effect was 42.33% in small field trial.The S-1 control effect was 59.99% at seedling stage in Xianxian County,and the control effect at adult stage was 47.90%.