نوع مقاله : علمی پژوهشی
نویسندگان
1 گروه زیستشناسی، دانشکده علوم پایه، دانشگاه پیام نور، تهران، ایران.
2 گروه گیاهپزشکی، پژوهشکده کشاورزی هستهای، پژوهشگاه علوم و فنون هستهای، تهران، ایران.
3 گروه بیوتکنولوژی، دانشگاه پیام نور، تهران، ایران. و بخش زیستشناسی سامانهها، پژوهشگاه بیوتکنولوژی کشاورزی ایران، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران/
4 گروه زیست شناسی، دانشکده علوم پایه، دانشگاه پیام نور، تهران، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Growth-promoting bacteria or plant probiotics are an effective part of biocompatible and sustainable agriculture. In this study, changes in some vegetatative i and plant physiological indicators and the biocontrol of P. ultimum (damping-off disease agent) in Lettuce plants treated with two types of growth stimulating bacteria (A lipoferum and A. brasilense) and a biocontrol species (B. subtilis and two gamma irradiated mutant isolates 419 and 600) were investigated in greenhouse conditions in the form of a completely randomized design (CRD) with four replications. The results showed bacterial treatments inthe all growth and physiological indicators, were significantly different from the control at the 5% level. In the P. ultimum inoculated treatments, the damping-off and diseases severity(DI) were significantly reduced as a result of the treatment with B. subtilis mutants obtained from gamma ray irradiation, but Azospirillium strains were not effective in biocontrol. The comparison of physiological inddexs in infected plants showed that peroxidase, polyphenol oxidase enzymes and proline increased and malonaldehyde decreased as a result of treatment with B. subtilis mutants. From the total results of this research, it can be concluded that the induction of mutation with gamma ray due to the improvement of antagonistic potential of B. subtilis ,leaded to increase the biological control activities of B. subtilis mutants without adverse effects on the growth and physiology of lettuce, so that the efficiency of these mutants in the biocontrol of pseudo-fungus P. ultimum and induction of physiological indicators of resistance in the lettuce plant is higher than that of Azosprilium efficiency.
کلیدواژهها [English]