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Guo F, Sun H, Yang J, Zhang L, Mu Y, Wang Y, Wu F. Improving food security and farmland carbon sequestration in China through enhanced rock weathering: Field evidence and potential assessment in different humid regions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166118. [PMID: 37574053 DOI: 10.1016/j.scitotenv.2023.166118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/02/2023] [Accepted: 08/05/2023] [Indexed: 08/15/2023]
Abstract
Enhanced rock weathering (ERW) in farmland is an emerging carbon dioxide removal technology with crushed silicate rocks for soil improvement. However, due to climatic variability and field data limitations, uncertainties remain regarding the influence of ERW on food security and soil carbon pools in temperate regions. This study focused to evaluate the crop productivity and carbon sequestration potential of farmland ERW in China by conducting field monitoring in different humid regions and ERW performance model. Additionally, the contribution of climate, soil, and management factors to ERW-mediated yield and carbon sequestration changes was explored using random forest and correlation networks. Field monitoring indicated that farmland ERW significantly improved crop yield in humid region (13.5 ± 5.2 %), along with notable improvements in soil pH and available nutrients. Precipitation (10.4-16.7 %) and soil pH (9.7-16.8 %) had the highest contribution on ERW mediated yield and carbon sequestration changes, but the contribution of management factors (24-26.2 %), especially N input (2.7-7.0 %), should not be disregarded. The model evaluation demonstrated that the carbon sequestration rate of farmland ERW in China can reach 0.28-0.40 Gt yr-1, thereby presenting an opportunity to expand and accelerate the nationally determined contributions of China. The mean sequestration cost of farmland ERW was 633 ± 161 CNY ¥ t-CO2-1, which was an attractive sequestration price considering the positive benefits of rock powder on soil pH and nutrients. Deploying ERW in acidified and mineral nutrient deficient regions was able to serve as an alternative to lime and part chemical fertilizers to improve yield and maximize agricultural sustainability and resource co-benefits. Farmland ERW also has the potential to resource silicate waste to assist traditional, difficult-to-decarbonize industries to reduce carbon emissions. As a result, a comprehensive assessment of existing artificial silicate waste materials could further expand the application of farmland ERW.
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Affiliation(s)
- Fuxing Guo
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling 712100, Shaanxi, PR China
| | - Haowei Sun
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, Shaanxi, PR China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling 712100, China
| | - Jing Yang
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, Shaanxi, PR China
| | - Linsen Zhang
- College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yan Mu
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Yanping Wang
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling 712100, Shaanxi, PR China; Fuping Modern Agricultural Comprehensive Experimental Demonstration Station, Northwest A&F University, Fuping 711700, Shaanxi, China
| | - Fuyong Wu
- College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, Yangling 712100, Shaanxi, PR China.
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Kiboi M, Musafiri C, Fliessbach A, Ng'etich O, Wakindiki I, Ngetich F. Selected conservation management strategies enhance maize yield stability in the sub-humid tropical agro-ecozone of Upper Eastern Kenya. Sci Rep 2023; 13:21728. [PMID: 38066076 PMCID: PMC10709456 DOI: 10.1038/s41598-023-49198-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 12/05/2023] [Indexed: 12/18/2023] Open
Abstract
Conservation management strategies have been recommended to enhance soil fertility, moisture retention, crop yield, and yield stability in rainfed agriculture. However, there is limited research on yield stability. We evaluated the effect of integrating soil inputs in conservation tillage on yield and yield stability in Meru South, Upper Eastern Kenya, for eleven consecutive cropping seasons. The trial treatments included conservation tillage without soil inputs (Mt), conservation tillage with soil inputs: sole inorganic fertilizer (F), residue + inorganic fertilizer (RF), residue + inorganic fertilizer + manure (RFM), residue + manure + legume Dolichos Lablab L. (RML), residue + Tithonia + manure (RTM), residue + Tithonia + phosphate rock (RTP) and conventional tillage (Control). Conservation tillage with RFM was the best-fit strategy for enhancing yields. There was heterogeneity in yield residual variance. A larger residual variance implied lesser yield stability. Mt treatment had the least yield residual variance of 0.12 Mg ha-2, followed by Ct and RML, 0.15 Mg ha-2, while RTM had the highest yield residual variance of 0.62 Mg ha-2. Contrarily, the most stable treatments had the least average yields. The study indicated a positive influence of incorporating soil inputs in conservation tillage on yield and suggests longer-term research for yield stability.
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Affiliation(s)
- Milka Kiboi
- Department of International Cooperation, Research Institute of Organic Agriculture (FiBL), Ackerstrasse 113, 5070, Frick, Switzerland.
| | - Collins Musafiri
- Cortile Scientific Limited, PO Box 34991-00100, Nairobi, Kenya
- Research Centre for Smallholder Farmers, PO Box 10451, 30100, Eldoret, Kenya
| | - Andreas Fliessbach
- Department of Soil Science, Research Institute of Organic Agriculture, (FiBL), Ackerstrasse 113, 5070, Frick, Switzerland
| | - Onesmus Ng'etich
- Department of Water and Agricultural Resource Management, University of Embu, PO Box 6, 60100, Embu, Kenya
| | | | - Felix Ngetich
- Cortile Scientific Limited, PO Box 34991-00100, Nairobi, Kenya
- Research Centre for Smallholder Farmers, PO Box 10451, 30100, Eldoret, Kenya
- School of Agricultural and Food Sciences, Jaramogi Oginga Odinga University of Science and Technology (JOOUST), PO Box 210-40601, Bondo, Kenya
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Xue YF, Li XJ, Yan W, Miao Q, Zhang CY, Huang M, Sun JB, Qi SJ, Ding ZH, Cui ZL. Biofortification of different maize cultivars with zinc, iron and selenium by foliar fertilizer applications. FRONTIERS IN PLANT SCIENCE 2023; 14:1144514. [PMID: 37746013 PMCID: PMC10513412 DOI: 10.3389/fpls.2023.1144514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 08/22/2023] [Indexed: 09/26/2023]
Abstract
Fertilizer-based biofortification is a strategy for combating worldwide malnutrition of zinc (Zn), iron (Fe) and selenium (Se). Field experiments were conducted to investigate the effects of foliar treatments on concentrations of Zn, Fe, Se, N and bioavailability of Zn and Fe in grains of three maize cultivars grown at three locations. We compared the efficacy of ZnO nanoparticles (ZnO-NPs), Zn complexed chitosan nanoparticles (Zn-CNPs), conventional ZnSO4 and a cocktail solution (containing Zn, Fe and Se). All treatments were foliar-applied at rate of 452 mg Zn L-1, plus urea. Applying ten-fold less Zn (at rate of 45.2 mg Zn L-1) plus urea in the form of ZnO-NPs, Zn-CNPs, or ZnSO4 resulted in no increase, or a negligible increase, in grain Zn concentration compared with deionized water. By contrast, among the different Zn sources plus urea applied by foliar sprays, conventional ZnSO4 was the most efficient in improving grain Zn concentration. Furthermore, foliar application of a cocktail solution effectively improved grain concentrations of Zn, Fe, Se and N simultaneously, without a grain yield trade-off. For example, the average grain concentrations were simultaneously increased from 13.8 to 22.1 mg kg-1 for Zn, from 17.2 to 22.1 mg kg-1for Fe, from 21.4 to 413.5 ug kg-1 for Se and from 13.8 to 14.7 g kg-1 for N by foliar application of a cocktail solution. Because grain yield was significantly negatively correlated with grain nutrient concentrations, the magnitude of increase in grain concentrations of Zn and Fe was most pronounced in the maize cultivar with the lowest grain yield (Zhengdan958 grown in Linyi). Foliar application of a cocktail solution also significantly decreased the phytic acid (PA) concentration, ratios of PA/Fe and PA/Zn in grains, indicating an increased bioavailability of Fe and Zn for human health. In conclusion, we found that a foliar application of a cocktail solution including Zn, Fe, Se and N was most effective for biofortification, but that the grains with the lowest yield contained the greatest concentration of these elements. This finding highlights the need to breed maize varieties that are capable of achieving both high grain yield and high grain nutritional quality to address food security and human health challenges.
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Affiliation(s)
- Yan-Fang Xue
- National Engineering Research Center of Wheat and Maize, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Northern Yellow-Huai Rivers Plain, Ministry of Agriculture, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- College of Agronomy, Liaocheng University, Liaocheng, China
| | - Xiao-Jing Li
- National Engineering Research Center of Wheat and Maize, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Northern Yellow-Huai Rivers Plain, Ministry of Agriculture, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- College of Life Sciences, Shandong Normal University, Jinan, China
| | - Wei Yan
- National Engineering Research Center of Wheat and Maize, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Northern Yellow-Huai Rivers Plain, Ministry of Agriculture, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Qi Miao
- College of Resources and Environment, China Agricultural University, Beijing, China
| | - Chun-Yan Zhang
- Food Crop Cultivation Institute, Linyi Academy of Agricultural Sciences, Linyi, China
| | - Meng Huang
- National Engineering Research Center of Wheat and Maize, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Northern Yellow-Huai Rivers Plain, Ministry of Agriculture, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Jin-Bian Sun
- National Engineering Research Center of Wheat and Maize, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Northern Yellow-Huai Rivers Plain, Ministry of Agriculture, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- College of Agronomy, Liaocheng University, Liaocheng, China
| | - Shi-Jun Qi
- National Engineering Research Center of Wheat and Maize, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Northern Yellow-Huai Rivers Plain, Ministry of Agriculture, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Zhao-Hua Ding
- National Engineering Research Center of Wheat and Maize, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Northern Yellow-Huai Rivers Plain, Ministry of Agriculture, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Zhen-Ling Cui
- National Engineering Research Center of Wheat and Maize, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Biology and Genetic Improvement of Maize in Northern Yellow-Huai Rivers Plain, Ministry of Agriculture, Maize Research Institute, Shandong Academy of Agricultural Sciences, Jinan, China
- College of Resources and Environment, China Agricultural University, Beijing, China
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Xu J, Zhu X, Yan F, Zhu H, Zhou X, Yu F. Identification of Quantitative Trait Loci Associated With Iron Deficiency Tolerance in Maize. FRONTIERS IN PLANT SCIENCE 2022; 13:805247. [PMID: 35498718 PMCID: PMC9048261 DOI: 10.3389/fpls.2022.805247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 03/07/2022] [Indexed: 05/10/2023]
Abstract
Iron (Fe) is a limiting factor in crop growth and nutritional quality because of its low solubility. However, the current understanding of how major crops respond to Fe deficiency and the genetic basis remains limited. In the present study, Fe-efficient inbred line Ye478 and Fe-inefficient inbred line Wu312 and their recombinant inbred line (RIL) population were utilized to reveal the physiological and genetic responses of maize to low Fe stress. Compared with the Fe-sufficient conditions (+Fe: 200 μM), Fe-deficient supply (-Fe: 30 μM) significantly reduced shoot and root dry weights, leaf SPAD of Fe-efficient inbred line Ye478 by 31.4, 31.8, and 46.0%, respectively; decreased Fe-inefficient inbred line Wu312 by 72.0, 45.1, and 84.1%, respectively. Under Fe deficiency, compared with the supply of calcium nitrate (N1), supplying ammonium nitrate (N2) significantly increased the shoot and root dry weights of Wu312 by 37.5 and 51.6%, respectively; and enhanced Ye478 by 23.9 and 45.1%, respectively. Compared with N1, N2 resulted in a 70.0% decrease of the root Fe concentration for Wu312 in the -Fe treatment, N2 treatment reduced the root Fe concentration of Ye478 by 55.8% in the -Fe treatment. These findings indicated that, compared with only supplying nitrate nitrogen, combined supply of ammonium nitrogen and nitrate nitrogen not only contributed to better growth in maize but also significantly reduced Fe concentration in roots. In linkage analysis, ten quantitative trait loci (QTLs) associated with Fe deficiency tolerance were detected, explaining 6.2-12.0% of phenotypic variation. Candidate genes considered to be associated with the mechanisms underlying Fe deficiency tolerance were identified within a single locus or QTL co-localization, including ZmYS3, ZmPYE, ZmEIL3, ZmMYB153, ZmILR3 and ZmNAS4, which may form a sophisticated network to regulate the uptake, transport and redistribution of Fe. Furthermore, ZmYS3 was highly induced by Fe deficiency in the roots; ZmPYE and ZmEIL3, which may be involved in Fe homeostasis in strategy I plants, were significantly upregulated in the shoots and roots under low Fe stress; ZmMYB153 was Fe-deficiency inducible in the shoots. Our findings will provide a comprehensive insight into the physiological and genetic basis of Fe deficiency tolerance.
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Affiliation(s)
- Jianqin Xu
- Key Laboratory of Plant-Soil Interaction (MOE), Centre for Resources, Environment and Food Security, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
| | - Xiaoyang Zhu
- Key Lab of Crop Heterosis and Utilization of Ministry of Education, Beijing Key Lab of Crop Genetic Improvement, China Agricultural University, Beijing, China
| | - Fang Yan
- Key Laboratory of Plant-Soil Interaction (MOE), Centre for Resources, Environment and Food Security, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
| | - Huaqing Zhu
- Key Laboratory of Plant-Soil Interaction (MOE), Centre for Resources, Environment and Food Security, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
| | - Xiuyu Zhou
- Key Laboratory of Plant-Soil Interaction (MOE), Centre for Resources, Environment and Food Security, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
| | - Futong Yu
- Key Laboratory of Plant-Soil Interaction (MOE), Centre for Resources, Environment and Food Security, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China
- *Correspondence: Futong Yu,
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Jiang L, Wang Y, Xia A, Wang Q, Zhang X, Jez JM, Li Z, Tan W, He Y. A natural single-nucleotide polymorphism variant in sulfite reductase influences sulfur assimilation in maize. THE NEW PHYTOLOGIST 2021; 232:692-704. [PMID: 34254312 DOI: 10.1111/nph.17616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Plants absorb sulfur from the environment and assimilate it into suitable forms for the biosynthesis of a broad range of molecules. Although the biochemical pathway of sulfur assimilation is known, how genetic differences contribute to natural variation in sulfur assimilation remains poorly understood. Here, using a genome-wide association study, we uncovered a single-nucleotide polymorphism (SNP) variant in the sulfite reductase (SiR) gene that was significantly associated with SiR protein abundance in a maize natural association population. We also demonstrated that the synonymous C to G base change at SNP69 may repress translational activity by altering messenger RNA secondary structure, which leads to reduction in ZmSiR protein abundance and sulfur assimilation activity. Population genetic analyses showed that the SNP69C allele was likely a variant occurring after the initial maize domestication and accumulated with the spread of maize cultivation from tropical to temperate regions. This study provides the first evidence that genetic polymorphisms in the exon of ZmSiR could influence the protein abundance through a posttranscriptional mechanism and in part contribute to natural variation in sulfur assimilation. These findings provide a prospective target to improve maize varieties with proper sulfur nutrient levels assisted by molecular breeding and engineering.
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Affiliation(s)
- Luguang Jiang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100094, China
| | - Yan Wang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100094, China
| | - Aiai Xia
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100094, China
| | - Qi Wang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100094, China
| | - Xiaolei Zhang
- Safety and Quality Institute of Agricultural Products, Heilongjiang Academy of Agricultural Sciences, Harbin, 150086, China
| | - Joseph M Jez
- Department of Biology, Washington University in St Louis, St Louis, MO, 63130, USA
| | - Zhen Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, 100094, China
| | - Weiming Tan
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100094, China
| | - Yan He
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100094, China
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Ramireddy E, Nelissen H, Leuendorf JE, Van Lijsebettens M, Inzé D, Schmülling T. Root engineering in maize by increasing cytokinin degradation causes enhanced root growth and leaf mineral enrichment. PLANT MOLECULAR BIOLOGY 2021; 106:555-567. [PMID: 34275101 PMCID: PMC8338857 DOI: 10.1007/s11103-021-01173-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/01/2021] [Indexed: 05/12/2023]
Abstract
Root-specific expression of a cytokinin-degrading CKX gene in maize roots causes formation of a larger root system leading to higher element content in shoot organs. The size and architecture of the root system is functionally relevant for the access to water and soil nutrients. A great number of mostly unknown genes are involved in regulating root architecture complicating targeted breeding of plants with a larger root system. Here, we have explored whether root-specific degradation of the hormone cytokinin, which is a negative regulator of root growth, can be used to genetically engineer maize (Zea mays L.) plants with a larger root system. Root-specific expression of a CYTOKININ OXIDASE/DEHYDROGENASE (CKX) gene of Arabidopsis caused the formation of up to 46% more root dry weight while shoot growth of these transgenic lines was similar as in non-transgenic control plants. The concentration of several elements, in particular of those with low soil mobility (K, P, Mo, Zn), was increased in leaves of transgenic lines. In kernels, the changes in concentration of most elements were less pronounced, but the concentrations of Cu, Mn and Zn were significantly increased in at least one of the three independent lines. Our data illustrate the potential of an increased root system as part of efforts towards achieving biofortification. Taken together, this work has shown that root-specific expression of a CKX gene can be used to engineer the root system of maize and alter shoot element composition.
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Affiliation(s)
- Eswarayya Ramireddy
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, Albrecht-Thaer-Weg 6, 14195, Berlin, Germany.
- Biology Division, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, 517507, Andhra Pradesh, India.
| | - Hilde Nelissen
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Jan Erik Leuendorf
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, Albrecht-Thaer-Weg 6, 14195, Berlin, Germany
| | - Mieke Van Lijsebettens
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Dirk Inzé
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9052, Ghent, Belgium
- VIB Center for Plant Systems Biology, 9052, Ghent, Belgium
| | - Thomas Schmülling
- Institute of Biology/Applied Genetics, Dahlem Centre of Plant Sciences (DCPS), Freie Universität Berlin, Albrecht-Thaer-Weg 6, 14195, Berlin, Germany.
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Siderophore production by Bacillus subtilis MF497446 and Pseudomonas koreensis MG209738 and their efficacy in controlling Cephalosporium maydis in maize plant. Arch Microbiol 2020; 203:1195-1209. [PMID: 33231747 PMCID: PMC7683328 DOI: 10.1007/s00203-020-02113-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/07/2020] [Accepted: 11/01/2020] [Indexed: 12/12/2022]
Abstract
Late wilt disease, caused by Cephalosporium maydis in maize plant, is one of the main economical diseases in Egypt. Therefore, to cope with this problem, we investigated the potentiality of plant growth promoting rhizobacteria in controlling this disease. Six strains (Bacillus subtilis, B. circulance, B. coagulanse, B. licheniformis, Pseudomonas fluroscence and P. koreensis) were screened for siderophore production, and using dual plate culture method and greenhouse experiment, antagonistic activity against C. maydis was studied. Using two superior strains, single and dual inoculation treatments in maize were applied in field experiment during the 2018 and 2019 seasons. Results indicated that B. subtilis and P. koreensis strains had shown the most qualitative and quantitative assays for siderophore production and antagonistic activities. In greenhouse, the most effective treatments on the pre- and post-emergence damping off as well as growth promotion of maize were T3 treatment (inoculated with B. subtilis), and T8 treatment (inoculated with P. koreensis). In field experiment, T5 treatment (inoculated with a mixture of B. subtilis and P. koreensis) showed significant increases in catalase (CAT), peroxidase (POX) and polyphenol oxidase (PPO) activities, as well as total chlorophyll and carotenoids than control treatments during the two growing seasons. In the same way, the highest effect in reducing infection and increasing the thickness of the sclerenchymatous sheath layer surrounding the vascular bundles in maize stem was observed and these results were a reflection of the increase in yield and yield parameters.
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