ﺑﺮرﺳﯽ ﺗﻮان ﺑﺮﺧﯽ ﺟﺪاﯾﻪ ﻫﺎي ﺑﺎﮐﺘﺮﯾﺎﯾﯽ ﺑﻪ ﻣﻨﻈﻮر ﻣﻬﺎر زﯾﺴﺘﯽ ﺑﯿﻤﺎري ﻟﮑﻪ زاوﯾﻪ اي ﺑﺎﮐﺘﺮﯾﺎﯾﯽ ﺧﯿﺎر

Introducing of Bacillus subtilis UTBMS7 as a probiotic bacteria against on wheat Evaluation of the potential of some bacterial isolates for biological control of angular leaf spot disease of cucumber

ﺑﺎﮐﺘﺮي ﻫﺎي ﻣﺤﺮك رﺷﺪ ﮔﯿﺎﻫﺎن ﺑﺎ داﺷﺘﻦ ﺗﻮان ﺑﺎﻻ در ﺟﻬﺖ اﻓﺰاﯾﺶ زﯾﺴﺖ ﺗﻮده و ﮐﻨﺘﺮل ﺑﯿﻤﺎري ﻫﺎي ﮔﯿﺎﻫﯽ، ﻣﯽ ﺗﻮاﻧﻨﺪ ﺟﺎﻧﺸﯿﻦ ﻣﻨﺎﺳﺒﯽ ﺑﺮاي ﺳﻤﻮم و ﮐﻮدﻫﺎي ﺷﯿﻤﯿﺎﯾﯽ در ﮐﺸﺎورزي ﺑﺎﺷﻨﺪ. ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﻣﻬﺎر زﯾﺴﺘﯽ Pseudomonas syringae pv. lachrymans ﻋﺎﻣﻞ ﺑﯿﻤﺎري ﻟﮑﻪ زاوﯾﻪ اي ﺧﯿﺎر در ﺷﺮاﯾﻂ آزﻣﺎﯾﺸﮕﺎه و ﮔﻠﺨﺎﻧﻪ ، از ﺑﺎﮐﺘﺮي ﻫﺎي ﺟﺪاﺳﺎزي ﺷﺪه از ﺧﺎك رﯾﺰوﺳﻔﺮ ﺧﯿﺎر ﺑﻪ ﻫﻤﺮاه ﺗﻌﺪادي از ﻧﻤﻮﻧﻪ ﻫﺎي ﻣﺠﻤﻮﻋﻪ ﺑﺎﮐﺘﺮي ﻫﺎي ﮔﺮوه ﮔﯿﺎه ﭘﺰﺷﮑﯽ داﻧﺸﮕﺎه وﻟﯽ ﻋﺼﺮ رﻓﺴﻨﺠﺎن اﺳﺘﻔﺎده ﺷﺪ. ﺑﻌﺪ از ﻏﺮﺑﺎﻟﮕﺮي آزﻣﺎﯾﺸﮕﺎﻫﯽ، ﭼﻬﺎر ﺟﺪاﯾﻪ ﮐﻪ داراي ﺗﻮان اﯾﺠﺎد ﻫﺎﻟﻪ ﺑﺎزدارﻧﺪه ﺑﻮدﻧﺪ ﺑﺮاي ﺑﺮرﺳﯽ ﻫﺎي ﺑﻌﺪي در ﺷﺮاﯾﻂ آزﻣﺎﯾﺸﮕﺎه و ﮔﻠﺨﺎﻧﻪ اﻧﺘﺨﺎب ﺷﺪﻧﺪ. ﺧﺼﻮﺻﯿﺎت ﻣﻬﺎر زﯾﺴﺘﯽ ﺟﺪاﯾﻪ ﻫﺎ ﻣﺎﻧﻨﺪ ﺗﻮﻟﯿﺪ ﻣﺘﺎﺑﻮﻟﯿﺖ ﻫﺎي ﺛﺎﻧﻮﯾﻪ و ﺑﻌﻀﯽ از وﯾﮋﮔﯽ ﻫﺎي ﺗﺤﺮﯾﮏ ﮐﻨﻨﺪﮔﯽ رﺷﺪ در ﺷﺮاﯾﻂ آزﻣﺎﯾﺸﮕﺎﻫﯽ ﻣﻮرد ارزﯾﺎﺑﯽ ﻗﺮار ﮔﺮﻓﺖ. در ارزﯾﺎﺑﯽ ﻫﺎي ﮔﻠﺨﺎﻧﻪ اي، ﺗﻮان ﺟﺪاﯾﻪ ﻫﺎي ﺑﺎﮐﺘﺮﯾﺎﯾﯽ در ﮐﻨﺘﺮل ﺑﯿﻤﺎري از ﻃﺮﯾﻖ ﻣﻤﺎﻧﻌﺖ در اﯾﺠﺎد ﻋﻼﺋﻢ ﺑﺎ ﺗﻌﯿﯿﻦ ﺳﻄﺢ زﯾﺮ ﻣﻨﺤﻨﯽ ﭘﯿﺸﺮﻓﺖ ﺑﯿﻤﺎري و اﻓﺰاﯾﺶ زﯾﺴﺖ ﺗﻮده ﮔﯿﺎه ﺧﯿﺎر ﺑﺎ ﺑﺮرﺳﯽ ﺷﺎﺧﺺ ﻫﺎي رﺷﺪي ﻣﻄﺎﻟﻌﻪ ﺷﺪ. ﻧﺘﺎﯾﺞ ﺑﺮرﺳﯽ ﮔﻠﺨﺎﻧﻪ اي ﻧﺸﺎن داد ﮐﻪ ﺟﺪاﯾﻪ 54 Pseudomonas fluorescens VRPF ﮐﺎرآﯾﯽ ﻣﻨﺎﺳﺒﯽ در ﻣﻬﺎر زﯾﺴﺘﯽ ﺑﯿﻤﺎري داﺷﺖ. در ﺷﺮاﯾﻂ ﮔﻠﺨﺎﻧﻪ، اﯾﻦ ﺟﺪاﯾﻪ ﺑﻪ ﺗﻨﻬﺎﯾﯽ و ﺗﻮأم ﺑﺎ ﺑﯿﻤﺎرﮔﺮ ﺑﻪ ﻃﻮر ﻣﻌﻨﯽ داري ﺑﺎﻋﺚ اﻓﺰاﯾﺶ زﯾﺴﺖ ﺗﻮده و ﮐﻨﺘﺮل ﺑﯿﻤﺎري ﻟﮑﻪ زاوﯾﻪ اي ﺧﯿﺎر ﮔﺮدﯾﺪ. ﭘﺲ از اﻧﺘﺨﺎب اﯾﻦ ﺟﺪاﯾﻪ، ﺑﺮﺧﯽ از وﯾﮋﮔﯽ ﻫﺎي آﻧﺘﺎﮔﻮﻧﯿﺴﺘﯽ، ﺧﺼﻮﺻﯿﺎت ﺑﯿﻮﺷﯿﻤﯿﺎﯾﯽ و ﺷﻨﺎﺳﺎﯾﯽ ﻣﻮﻟﮑﻮﻟﯽ آن در آزﻣﺎﯾﺸﮕﺎه ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. ﻫﻤﭽﻨﯿﻦ ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از اﻧﺪازه ﮔﯿﺮي آﻧﺰﯾﻢ ﻫﺎي ﭘﺮاﮐﺴﯿﺪاز، ﮔﺎﯾﺎﮐﻮل ﭘﺮاﮐﺴﯿﺪاز، ﻓﻨﯿﻞ آﻻﻧﯿﻦ آﻣﻮﻧﯿﺎﻟﯿﺎز، ﭘﻠﯽ ﻓﻨﻞ اﮐﺴﯿﺪاز و ﻣﺤﺘﻮي ﻓﻨﻞ ﮐﻞ روﻧﺪ اﻓﺰاﯾﺸﯽ را ﻧﺸﺎن داد.

Plant growth-promoting rhizobacteria have great potential for increasing plant biomass and controlling plant diseases. Therefore PGPRs can be a good substitute for the use of pesticides and chemical fertilizers in agriculture. For evaluation of the effects of antagonistic activities of several PGPRs against Pseudomonas syringae pv. lachrymans the causal agent of cucumber angular leaf spot disease in laboratory and greenhouse conditions. Several bacteria isolated from different cucumber rhizosphere soil in Kerman province and a number of bacterial strains in the collection of Vali-e-Asr University of Rafsanjan were used. After in vitro screening, four isolates with the ability of growth inhibitory effect were selected for further studies in vitro and in planta. Antibacterial activity characteristics of biocontrol agents such as the production of secondary metabolites and some of their plant growth promoting traits were evaluated in vitro. During in planta study, the ability of bacterial strains to prevent the development of symptoms using the area under disease progress curve (AUDPC) and increasing the biomass of cucumber plants were evaluated. Greenhouse study showed that Pseudomonas fluorescens VRPF 54 strain has high biocontrol efficacy. During in planta study, this strain, both alone and in the interaction plant-pathogen in comparison with the control plant, significantly increased biomass and controlled cucumber leaf spot disease. After the selection of this strain, some of its antagonistic activities, biochemical properties and molecular identification were screened in vitro. Also, the assay of antioxidant enzyme activity such as peroxidase, guaiacol peroxidase, phenylalanine ammonia lyase, polyphenol oxidase and total phenol content were considerably increased.