فهرست مطالب mohsen sasani

Modern agriculture in the 21st century must provide food security for this growing population, which means producing more food and fiber with less labor. Therefore, agriculture in this century requires smart investment based on more efficient and environmentally friendly production methods. Common wheat root rot caused by B. sorokiniana is one of the most important pathogens of wheat, which causes economic losses every year. In this research, from 180 Bacillus isolates from the samples collected from the wheat fields of Hamadan province, wastes of edible mushrooms, palm wastes and wood wastes, 9 isolates were able to produce γ-PGA with different production rates. 2 isolates were able to produce γ-PGA independently of glutamic acid. Bacillus velezensis UTB97 with a production rate of 40 g/L γ-PGA was selected as the superior producer isolate. UTB97 could prevent 65% growth of pathogenic fungi in laboratory conditions by dual culture method. Greenhouse result showed that the treatment of UTB97 and UTB97 + γ-PGA was able to control Common wheat root rot disease by 59 and 73%, respectively, compared to the control treatment, and also the treatment of UTB97 + γ-PGA was able to increase the growth index of wheat. (stem length and root dry weight), in the presence and absence of the pathogenic fungus.

Root and crown rot of wheat is one of the most important diseases that caused by Fusarium species. The present study was conducted with the aim of seed Bioprime with bacteria to control fungal pathogens of root and crown rot and improving some growth indicators of wheat in laboratory and greenhouse conditions in 2019. The Effect of bacterial inhibition on fungal pathogen growth in vitro and in cross-culture test, metabolites and bacterial extracts were 60, 50 and 30 percent respectively. Bacterial isolates were able to produce biocontrol enzymes, metabolites and hormones of growth promoting such as auxin, siderophore, and ACC deaminase. In vitro, infection of wheat seeds before priming had a beneficial effect on increasing the efficiency of bioprime technique with bacteria, because in uninfected wheat seeds, bacteria did not play a role in reducing pathogenic fungi. Bioesmoprim, osmoprime and halloprime had the most impact in controlling the pathogenic fungus and improving the growth indices of wheat (germination percent, length and weight of root and stem) in greenhouse conditions, respectively. Although Talc powder and gum in germinated seeds reduced the fungal disease of root and crown rot, but seed germination percentage of wheat seeds were reduced, too. The combination of talc powder + xanthan gum with bacteria improved the mentioned traits.

Wheat is one of the most important agricultural products in Iran, that plays an important role in ensuring food security. Crown and root rot disease by F. pseudograminearum is one of the most important pathogens that cause economic damages every year. In this study, 80 isolates of Bacillus were isolated from wheat rhizosphere. In dual-culture test, UTB 3, UTB 11, UTB 22, UTB 4 and UTB 7 isolates with 60, 55, 37.5, 22.5 and 20% maximum ability, respectively. In effect test of volatile metabolites on inhibination the growth of F. pseudograminearum, UTB 3, UTB 7 and UTB 11 with 54, 52 and 49% showed the highest percentage of inhibition of fungal growth. These isolates were also capable of nitrogen fixation, production of siderophore and extracellular enzymes involved in biological control (protease, lipase and chitinase), but none of the isolates were able to produce phosphatase enzyme. Greenhouse studies by treating wheat seeds with selected isolates showed that UTB 3 was able to control crown and root rot of wheat by 80.33% compared to the control treatment. Also, this isolate could increase the growth indices of wheat (stem length and root dry weight) in the presence and absence of pathogenic fungi. Therefore, this isolate is introduced as the selected isolate to control crown and root rot disease and increase wheat growth indices.