Shagal, ManvikaPandey, Shubham2024-10-292024-10-292023-08-01Theses of M.Sc.https://krishikosh.egranth.ac.in/handle/1/5810215963Iron deficiency is a widespread concern in both animals and plants, leading to detrimental effects on health and productivity. Iron-deficient crops pose significant challenges to global food security and human nutrition. To increase iron bioavailability in tomato plants, this study focuses on utilizing the iron-chelating capabilities of siderophore-producing bacteria. In this study, four siderophore-positive bacterial strains namely Pseudomonas cedrina B2, Pseudomonas constantinni R3, Pseudomonas paralactis R4 and Streptomyces lavendulae R5 taken from departmental culture collection were characterized for biochemical and plant growth promoting characteristics such as the ability to solubilize phosphorus, potassium and produce ammonia. In addition the siderophore production of the strains was evaluated at different pH, temperature, and bacteriological media where R4 was found out to be the best siderophore producer amongst the others followed by R3. On the basis of their biochemical and plant growth promoting characteristics two consortia were prepared i.e. Consortium I(R4 +R5) and Consortium II(R3 +R4). The two consortia T8(R4 + R5) and T9(R3 + R4) along with two positive controls T2(organic) and T3(inorganic), and the bacterial isolates were assessed for their impacts on tomato growth, yield, and the enhancement of fruit nutritional and textural quality in a pot trial. The findings of the current study showed that, in contrast to control the pots treated with siderophore-producing bacteria had increased plant height, shoot and root weight, chlorophyll content and fruit yield. The tomatoes from treated plants had significantly higher contents of lycopene, Fe, phenol and ascorbic acid. Amongst the bacterial treatments, T9 i.e. consortium of R4 and R3 was best as it resulted in higher plant growth parameters, fruit nutritional metrics and skin strength. Besides this the bacterial treatment T9, also significantly enhanced soil enzymatic properties such as Fluorescein diacetate and Dehydrogenase. These results show that siderophore-producing bacteria may increase iron absorption and bioavailability in tomatoes, thus opening up the possibilities for development of these strains as bioformulation for increased crop yields and enhanced soil health.EnglishThesis