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RESEARCH ARTICLE

Seed-applied zinc-solubilising Bacillus biofertilisers improve antioxidant enzyme activities, crop productivity, and biofortification of maize

Muhammad Zahid Mumtaz https://orcid.org/0000-0001-8014-7720 A B * , Maqshoof Ahmad https://orcid.org/0000-0001-5438-5696 B * , Muhammad Zafar-ul-Hye https://orcid.org/0000-0001-6482-4656 C , Muhammad Saqib D , Muhammad Fakhar U Zaman Akhtar B and Muhammad Saqlain Zaheer E
+ Author Affiliations
- Author Affiliations

A Institute of Molecular Biology and Biotechnology, The University of Lahore, Main Campus, Lahore 54000, Pakistan.

B Department of Soil Science, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan.

C Department of Soil Science, Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan 60800, Pakistan.

D Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad 38040, Pakistan.

E Department of Agricultural Engineering, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan 64200, Pakistan.


Handling Editor: Youhong Song

Crop & Pasture Science 73(5) 503-514 https://doi.org/10.1071/CP21415
Submitted: 7 April 2021  Accepted: 21 August 2021   Published: 5 January 2022

© 2022 The Author(s) (or their employer(s)). Published by CSIRO Publishing

Abstract

Biofertiliser is considered a promising biofortification intervention that can integrate with plant breeding as well as agronomic measures to overcome malnutrition in regions where the staple diet is cereal. This study was conducted to improve maize (Zea mays L.) productivity and biofortification with zinc (Zn) through the application of Zn-solubilising biofertilisers. Four pre-isolated, promising Zn-solubilising Bacillus strains, Bacillus sp. ZM20, B. aryabhattai ZM31, B. aryabhattai S10 and B. subtilis ZM63, were coated on maize seeds by forming slurry-based sole- and co-inoculated biofertilisers. The treated maize seeds were grown in a spring season (Trial I) and the experiment was repeated the following year on the same field (Trial II). The seed-applied co-inoculated Bacillus biofertiliser formulations significantly promoted antioxidant enzyme activities (ascorbate peroxidase, peroxidase and superoxide dismutase), growth and yield attributes, and nutrient accumulation in maize grains during both field trials compared with sole-inoculated biofertiliser formulations. Application of ZM31–ZM63 biofertiliser formulation showed a greater increase in these attributes than other biofertiliser formulations, as well as an increase in grain iron (Fe) concentration (up to 1.69-fold in Trial I and 1.77-fold in Trial II) and Zn concentration (up to 1.50-fold in Trial I and 1.41-fold in Trial II) relative to the uninoculated control. Fe and Zn concentrations in maize grains resulting from the application of seed-based Bacillus biofertiliser formulations could fulfill the minimum required level of these nutrients for daily intake. From the study, recommendation can be made to apply Zn-solubilising bioinoculants for the biofortification of maize grains to overcome malnutrition issues in regions with cereal-based staple diets.

Keywords: antioxidant enzymes, Bacillus spp., biofertilisers, biofortification, crop productivity, seed priming, Zea mays, zinc.


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