Physiology and Genetics of Drought Tolerance in Cowpea and Winter Wheat
Physiology and Genetics of Drought Tolerance in Cowpea and Winter Wheat

Author: David Adrian Verbree

Publisher:

Published: 2015

Total Pages:

ISBN-13:

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In the wake of rising temperatures, erratic rainfall, and declining ground water table, breeding for drought tolerance in food crops has become a top priority throughout the world. Phenotyping a large population of breeding lines for drought tolerance is time-consuming and often unreliable due to multiple possible mechanisms involved. In cowpea (Vigna unguiculata L. Walp), a box-screening method has been used to partition the confounding effects that shoot and root traits have on drought tolerance by restricting root growth and providing a homogeneous soil moisture environment across genotypes. Nonetheless, multiple mechanisms of shoot drought tolerance have been reported which further complicate phenotyping. In winter wheat (Triticum aestivum L.), canopy temperature depression (CTD) has been proposed as a good indicator of drought tolerance. The recent development of low-cost thermal imaging devices could enable high-throughput phenotyping of canopy temperature. While CTD can be an indicator of overall plant water status, it can be confounded by high stomatal resistance, which is another seemingly contradictory mechanism of drought tolerance. The objectives of this study were to explore the physiological basis and genetics of the two mechanisms of shoot drought tolerance previously reported in cowpea and to develop and evaluate a method of high-throughput phenotyping of drought tolerance in winter wheat using thermal imaging. In cowpea, a legume well known for its tight stomatal control, no differences in gas exchange between drought tolerant and susceptible genotypes were observed. A unifoliate stay-green trait was discovered that segregates as a single recessive gene. However, it did not correlate with trifoliate necrosis or overall drought tolerance. In winter wheat, CTD did not always correlate with yield under rainfed conditions. One drought-tolerant cultivar, in particular, had the hottest canopy temperature, possibly because it was able to conserve moisture by closing its stomata whereas another closely related drought-tolerant cultivar had the coolest canopy temperature. Therefore, it appears that no single method of phenotyping for drought tolerance can be broadly applied across all genotypes of a given species due to possible contrasting mechanisms of drought-tolerance and environmental differences. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/152439

Climate Change and Crop Stress
Climate Change and Crop Stress

Author: Arun K.Shanker

Publisher: Academic Press

Published: 2021-11-19

Total Pages: 601

ISBN-13: 0128165359

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Climate Change and Crop Stress: Molecules to Ecosystems expounds on the transitional period where science has progressed to ‘post-genomics’ and the gene editing era, putting field performance of crops to the forefront and challenging the production of practical applicability vs. theoretical possibility. Researchers have concentrated efforts on the effects of environmental stress conditions such as drought, heat, salinity, cold, or pathogen infection which can have a devastating impact on plant growth and yield. Designed to deliver information to combat stress both in isolation and through simultaneous crop stresses, this edited compilation provides a comprehensive view on the challenges and impacts of simultaneous stresses. Presents a multidisciplinary view of crop stresses, empowering readers to quickly align their individual experience and perspective with the broader context Combines the mechanistic aspects of stresses with the strategic aspects Presents both abiotic and biotic stresses in a single volume

Plant Amino Acids
Plant Amino Acids

Author: Bijay K. Singh

Publisher: CRC Press

Published: 1998-10-27

Total Pages: 636

ISBN-13: 1482270064

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Covers the basic knowledge of the regulation of biosynthesis of various amino acids in plants and the application of this knowledge to the discovery of novel inhibitors of amino acid biosynthesis and for enhancing the nutritional value of plant products. Provides an exhaustive list of pathway inhibitors.

Salinity and Water Stress
Salinity and Water Stress

Author: M. Ashraf

Publisher: Springer Science & Business Media

Published: 2008-12-26

Total Pages: 241

ISBN-13: 140209065X

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Salinity and water stress limit crop productivity worldwide and generate substantial economic losses each year, yet innovative research on crop and natural resource management can reveal cost-effective ways in which farmers can increase both their productivity and their income. Presenting recent research findings on salt stress, water stress and stress-adapted plants, this book offers insights into new strategies for increasing the efficiency of crops under stressful environments. The strategies are based on conventional breeding and advanced molecular techniques used by plant physiologists, and are discussed using specific case studies to illustrate their potential. The book emphasizes the effects of environmental factors on specific stages of plant development, and discusses the role of plant growth regulators, nutrients, osmoprotectants and antioxidants in counteracting their adverse affects. Synthesising updated information on mechansisms of stress tolerance at cell, tissue and whole-plant level, this book provides a useful reference text for post graduate students and researchers involved in the fields of stress physiology and plant physiology in general, with additional readership amongst researchers in horticulture, agronomy, crop science, conservation, environmental management and ecological restoration.

Drought Stress in Maize (Zea mays L.)
Drought Stress in Maize (Zea mays L.)

Author: Muhammad Aslam

Publisher: Springer

Published: 2015-11-20

Total Pages: 79

ISBN-13: 3319254421

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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.