Isolating and identification of endophytic bacteria and evaluation of its effectiveness in control of Smut and Damping-off diseases on wheat

Abstract

The study was conducted to assess the effectiveness of Endophytic bacteria in controlling of Pythium aphanidermatum and Tilletia caries/Tilletia laevis. 50 isolates of bacteria were isolated from wheat plant tissues from different regions of Salahaddin province. The results of the direct antagonist test of the isolated bacteria with the pathogen P. aphanidermatum indicated that the extent of inhibition ranged from (0.3-9.3 mm) with the highest inhibition rate in SHSt2 isolate with a inhibition zone of 9.3 mm, this isolate diagnosed to the species level of Pseudomonas flvescens (SHSt2. In the field experiment, the treatment of P. flvescens (SHSt2. (seeds + spraying 10¹² bacterial cells/ml) showed a significant superiority in the vegetative markers such as chlorophyll content and height of the plant. Treatment of P. flvescens (SHSt2) has affected the infection rate of pathogens P. aphanidermatum and T. laevis/T. caries with the lowest infection rate in the treatment (seeds + spraying 10¹² bacterial cells/ml) resulting in 19.94 and 11.13% respectively, compared to the highest infection rate in the of the presence of pathogens, resulting in 81.57 and 58.47% respectively. In the productivity markers, the same treatment of P. flvescens (SHSt2) increased the total weight of the plant by reaching the highest weight in the presence of pathogens P. aphanidermatum and T. laevis/T. caries resulting in 60.4 and 58.71 g respectively, compared to the lowest weight in the control of pathogens at 26.47 and 20.56 g, respectively. In addition, the effect of P. flvescens (SHSt2) (seeds + spraying 10¹² bacterial cells/ml) was reflected on the index of harvest, in presence of pathogens P. aphanidermatum and T. laevis / T. caries which reached to 36.5 and 28.75%, respectively, compared to the lowest harvest index 22.42 and 18.42% in present of both pathogens, respectively.