Drought Stress in Maize (Zea mays L.)

Effects, Resistance Mechanisms, Global Achievements and Biological Strategies for Improvement

Author: Muhammad Aslam

Publisher: Springer

ISBN:

Category: Science

Page: 74

View: 852

This book focuses on early germination, one of maize germplasm most important strategies for adapting to drought-induced stress. Some genotypes have the ability to adapt by either reducing water losses or by increasing water uptake. Drought tolerance is also an adaptive strategy that enables crop plants to maintain their normal physiological processes and deliver higher economical yield despite drought stress. Several processes are involved in conferring drought tolerance in maize: the accumulation of osmolytes or antioxidants, plant growth regulators, stress proteins and water channel proteins, transcription factors and signal transduction pathways. Drought is one of the most detrimental forms of abiotic stress around the world and seriously limits the productivity of agricultural crops. Maize, one of the leading cereal crops in the world, is sensitive to drought stress. Maize harvests are affected by drought stress at different growth stages in different regions. Numerous events in the life of maize crops can be affected by drought stress: germination potential, seedling growth, seedling stand establishment, overall growth and development, pollen and silk development, anthesis silking interval, pollination, and embryo, endosperm and kernel development. Though every maize genotype has the ability to avoid or withstand drought stress, there is a concrete need to improve the level of adaptability to drought stress to address the global issue of food security. The most common biological strategies for improving drought stress resistance include screening available maize germplasm for drought tolerance, conventional breeding strategies, and marker-assisted and genomic-assisted breeding and development of transgenic maize. As a comprehensive understanding of the effects of drought stress, adaptive strategies and potential breeding tools is the prerequisite for any sound breeding plan, this brief addresses these aspects.

Maize (Zea Mays L.) Under Drought Stress

Effects of Drought Stress on Maize from Germination to Physiological Maturity. Selection Criteria for Drought Tolerance

Author: Muhammad Aslam

Publisher: LAP Lambert Academic Publishing

ISBN:

Category:

Page: 84

View: 542

Stresses create barriers in normal growth and developmental processes of plants. Plant life cycle is distorted variably depending upon severity of stress, type of stress and growth stage of plant. Among stresses drought is most severe regarding adverse effects to the agricultural crop productivity at Global level. Among cereals, maize is very important cereal due to multiple utilization for versatile purposes. Drought also affects the maize as it does with other crops so, there is dire need to recognize the effects of drought on maize in detail. This book is typically focusing on interference by drought in maize life cycle. Determination of possible effects on a plant enables the researcher to explore the resources to ameliorate the adverse effects of stress. Furthermore, recognition of plant traits to exploit in breeding, selection and screening of germplasm is also very critical stage in-order to identify suitable traits. This book also include the traits to be used as selection criteria for improvement against drought stress in maize.

Drought Stress in Maize (Zea Mays L.)

Effects, Resistance Mechanisms, Global Achievements and Biological Strategies for Improvement

Author: Muhammad Aslam

Publisher:

ISBN:

Category:

Page:

View: 576

This book focuses on early germination, one of maize germplasm most important strategies for adapting to drought-induced stress. Some genotypes have the ability to adapt by either reducing water losses or by increasing water uptake. Drought tolerance is also an adaptive strategy that enables crop plants to maintain their normal physiological processes and deliver higher economical yield despite drought stress. Several processes are involved in conferring drought tolerance in maize: the accumulation of osmolytes or antioxidants, plant growth regulators, stress proteins and water channel proteins, transcription factors and signal transduction pathways. Drought is one of the most detrimental forms of abiotic stress around the world and seriously limits the productivity of agricultural crops. Maize, one of the leading cereal crops in the world, is sensitive to drought stress. Maize harvests are affected by drought stress at different growth stages in different regions. Numerous events in the life of maize crops can be affected by drought stress: germination potential, seedling growth, seedling stand establishment, overall growth and development, pollen and silk development, anthesis silking interval, pollination, and embryo, endosperm and kernel development. Though every maize genotype has the ability to avoid or withstand drought stress, there is a concrete need to improve the level of adaptability to drought stress to address the global issue of food security. The most common biological strategies for improving drought stress resistance include screening available maize germplasm for drought tolerance, conventional breeding strategies, and marker-assisted and genomic-assisted breeding and development of transgenic maize. As a comprehensive understanding of the effects of drought stress, adaptive strategies and potential breeding tools is the prerequisite for any sound breeding plan, this brief addresses these aspects.

Use of Soil Apparent Electroconductivity (ECa) to Determinate Potential Stress Management Zones for Drought Tolerance Selection in Maize (Zea Mays L.)

Author: Andres Francisco Reyes

Publisher:

ISBN:

Category:

Page:

View: 622

Drought is one of the most important drivers of yield loss in maize (Zea Mays L.). Maize breeders have worked to improve yield potential under limited irrigation conditions over the past 60 years. A better understanding of the factors underlying yield loss under drought and of the methods to improve stress imposition are required to improve the efficiency of selection. Management of controlled stress requires a detailed understanding of the site's characteristics in order to reduce the deleterious effect of environmental variation due to field variability. In this research, relations between apparent electroconductivity and plant traits frequently used for maize drought screening were established using data collected during three years in one field in the central valley of California. Spatial and temporal variability in grain yield were described using clustering of standardized data and generating a series of field maps for three years of field testing. Soil physical properties were used to estimate hydraulic characteristics of the soil such as saturation, saturated soil hydraulic conductivity, field capacity, and wilting point, and these estimates were correlated to apparent soil electroconductivity for this specific field. In addition, models were developed to explore the potential of using soil electroconductivity as predictor variable for soil texture characteristics. Finally, management zones were created using integrated clusters calculated from grain yield across the three years as the response varaible and site specific electroconductivity data as predictor variables. The results indicate that soil apparent electroconductivity can be a useful and relatively inexpensive tool to assess field variability and define management zones describing site specific potential for drought stress studies.

Ectopic Expression of an Arabidopsis Glutaredoxin Increases Thermotolerance in Maize During Reproductive Developmental Stages

Author: Stuart A. Sprague

Publisher:

ISBN:

Category:

Page:

View: 790

Drought and heat stress are two of the biggest constraints to global food production. Abiotic stress response pathways are complex and consist of osmotic adjustors, macromolecule stabilizers, and antioxidants to counteract the damaging nature of abiotic stress induced reactive oxygen species (ROS) accumulation. In this work, we studied the effect of overexpression of an Arabidopsis glutaredoxin, AtGRXS17, on heat tolerance in maize (Zea mays L.) and drought tolerance in rice (Orzya sativa L.). Glutaredoxins (GRXs) are proteins cable of reducing disulfide bonds, therefore regulating the cellular redox status, and require glutathione for regeneration. Ectopic expression of AtGRXS17 in maize resulted in increased heat stress tolerance during flowering. AtGRXS17 enhanced heat tolerance by increasing kernel set and total grain yield during heat treatments, compared to wild type controls. Our results indicated that AtGRXS17-expressing maize plants produce heat tolerant pollen with higher germination rates than wild type when challenged during heat treatments. Furthermore, AtGRXS17-expressing plants were less susceptible to post pollination heat induced kernel abortion. Rice plants expressing AtGRXS17 were also tolerant to abiotic stress. AtGRXS17-expressing rice was more tolerant to drought stress challenges and consistently survived drought treatments. A nontargeted metabolomics study revealed distinct changes in profiles of key metabolite groups in response to drought stress. Soluble sugars and amino acids accumulate as osmotic adjustors while antioxidants, such as glutathione, accumulate to mediate ROS accumulation and regulate redox activity. All genotypes accumulated amino acids, soluble sugars, and raffinose family oligosaccharides in response to drought stress. Our results indicated AtGRXS17-expression affected several pathways known to increase drought tolerance. Altered sugar metabolites suggested a redox modulation of sucrose synthase activity and significant increases in the secondary sulfur assimilation pathway metabolites suggested altered sulfur metabolism. This research provides new insights into ability of GRXs to improve heat tolerance and crop yield in maize and functions of GRXs in affecting metabolite profiles contributing to increased drought tolerance in rice.

Effect of Water Stress on Zea Mays Plant Grown Under the Greenhouse

Author: Mohamad Huzaifi Bin Ahmad Asri

Publisher:

ISBN:

Category: Bioprosess engineering

Page: 65

View: 831

Water stress is one of the major abiotic stress factors thatcan effect on maize(Zea mays L.)plant growth. This study was focused on the effect of water stress on maize growth under greenhouse condition in Perlis, Malaysia. The experiment was conducted in the greenhouse at campus Jejawi Universiti Malaysia Perlis over the duration of 10 weeks from 7 January 2016 to 11 March 2017. The maize was grown under four different level of water stress which is Control (no stress), Treatment 1 (low), Treatment 2 (medium), and Treatment 3(severe). The maize plant was irrigated daily according to their different percentage of total available water (TAW). Control is 100% of TAW, Treatment 1 is 75% of TAW, Treatment 2 is 50% of TAW and Treatment 3 is25% of TAW. The main objective in this study is to determine the effect of water stress on maize growth. In control and different water stress condition, the morphological of maize growth also was measured such as height of maize plant, diameter of stem, number of leaves and area of leaves. At the end of this experiment, the responses of growth parameters to the different condition water stress wereanalyze using ANOVA.The results obtained indicated that for treatment in no stress condition is better compared to others treatment. The result shows the mean height of plant for no stress, mild, medium and severe stress is 141.33 cm, 120.00 cm, 89.33cm and 56.67 cm respectively. Besides, diameter of stem for each treatment also shows the no stress condition is better. It is proved by the mean diameter of stem for no stress, mild, medium and sever stress is 2.17 cm, 2.13 cm, 2.00 cm, and 1.67 cm respectively. Overall, the growth of maize shows more effective for maize grown under no stress and mild stress condition.