Wheat Germplasm Growth Dynamics Influenced by Zinc Solubilizing Bacteria

Abstract

Zinc deficiency is a major constraint limiting wheat productivity, particularly in arid and semi-arid regions where soil micronutrient availability is inherently low. Microbial inoculants such as zinc solubilizing bacteria (ZSB) have emerged as promising biofertilizers to improve nutrient use efficiency and crop growth. This study evaluated the effects of three ZSB strains—Pseudomonas putida (M6), P. aeruginosa (M9), and P. fluorescens (M27)—on growth dynamics and zinc uptake in three wheat varieties (AZRC Dera, AZRC Daman, and PS 13) under greenhouse conditions at the Arid Zone Research Center, Dera Ismail Khan. Treatments were arranged in a completely randomized design, and growth parameters including germination percentage, plant height, tiller number, root and shoot length, fresh and dry biomass, plant zinc uptake, and post-harvest soil zinc content were recorded. Results indicated that inoculated treatments significantly outperformed controls across most parameters. P. fluorescens (M27) showed the strongest effects, improving germination by 18–22%, plant height by 20–28%, tiller number by 25–30%, and zinc uptake by up to 35% compared with non-inoculated plants. Reductions in post-harvest soil zinc availability further confirmed enhanced plant absorption. These findings highlight the potential of ZSB to mobilize soil zinc reserves, promote root and shoot development, and enhance overall wheat productivity. The study concludes that P. fluorescens (M27) and P. aeruginosa (M9) are particularly effective biofertilizer candidates for wheat under zinc-limited soils. Adoption of these microbial inoculants could reduce dependency on chemical fertilizers and support sustainable crop production in arid agroecosystems.