L-Tryptophan-Dependent Auxin-Producing Plant-Growth-Promoting Bacteria Improve Seed Yield and Quality of Carrot by Altering the Umbel Order

Carrot (Daucus carota L.) seed quality is affected by umbel position due to uneven maturation of carrot seeds produced in different orders. However, keeping this view, we tested whether could be improved with the suppression tertiary umbels under exogenous auxin application. Using auxin-producing bacterial isolates, i.e., Bacillus sp. MN54, Enterobacter MN17, Pantoea MN34, and Burkholderia phytofirmans PsJN, arrangements order were evaluated terms production. The results revealed that production plant-growth-promoting rhizobacteria showed significant differences among measured growth indices, yield, attributes. selected endophytic strains co-applied via foliar application all growth- yield-related traits, as well enzymatic activities carrots. Noticeably, MN17+L-tryptophan MN34+L-tryptophan effectively minimized number increasing secondary umbels. Furthermore, treating PsJN+L-tryptophan resulted reduced conductivity leachates malondialdehyde levels primary, secondary, seeds. These findings collectively indicate potential alter arrangement, leading yield quality. This study implies producers can consider employing specific PGPB strains, particularly MN34+L-tryptophan, suppress achieve higher yields high-quality