Seedling Shoot and Root Growth Responses Among Soybean (Glycine Max) Genotypes to Drought Stress

Seedling Shoot and Root Growth Responses Among Soybean (Glycine Max) Genotypes to Drought Stress PDF Author: Obed Mwenye
Publisher:
ISBN:
Category : Electronic books
Languages : en
Pages : 0

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Book Description
Drought stress is a major limiting factor in soybean production in South Africa. The development of soybean varieties with enhanced tolerance to soil waterlimited induced stress (WLIS) is one sustainable way to deal with drought. Root traits have shown strong potential for improvement of drought tolerance through breeding. The objectives of this study were to evaluate seedling shoot- and root growth responses under WLIS in order to study root morphology as a mechanism to cope with drought stress and to determine if there were genotypic differences in shoot- and root morphology between drought tolerant and -sensitive soybean genotypes. Seedlings of three drought tolerant and one sensitive genotype were subjected to soil WLIS in deep-root-pots for 21 days. Results suggested significant genotypic differences for shoot length, number of leaves, tap root length and root-to-shoot length ratio. Soybean tolerant genotypes were associated with moderate shoot biomass, deep rooting abilities and maintained a large root-to-shoot ratio under WLIS conditions. In contrast, the sensitive genotype was associated with a reduced root-to-shoot ratio and shallower root system. Soybean genotypes showed varying seedling root growth responses to soil WLIS, while shoot biomass characteristics were similar.

Seedling Shoot and Root Growth Responses Among Soybean (Glycine Max) Genotypes to Drought Stress

Seedling Shoot and Root Growth Responses Among Soybean (Glycine Max) Genotypes to Drought Stress PDF Author: Obed Mwenye
Publisher:
ISBN:
Category : Electronic books
Languages : en
Pages : 0

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Book Description
Drought stress is a major limiting factor in soybean production in South Africa. The development of soybean varieties with enhanced tolerance to soil waterlimited induced stress (WLIS) is one sustainable way to deal with drought. Root traits have shown strong potential for improvement of drought tolerance through breeding. The objectives of this study were to evaluate seedling shoot- and root growth responses under WLIS in order to study root morphology as a mechanism to cope with drought stress and to determine if there were genotypic differences in shoot- and root morphology between drought tolerant and -sensitive soybean genotypes. Seedlings of three drought tolerant and one sensitive genotype were subjected to soil WLIS in deep-root-pots for 21 days. Results suggested significant genotypic differences for shoot length, number of leaves, tap root length and root-to-shoot length ratio. Soybean tolerant genotypes were associated with moderate shoot biomass, deep rooting abilities and maintained a large root-to-shoot ratio under WLIS conditions. In contrast, the sensitive genotype was associated with a reduced root-to-shoot ratio and shallower root system. Soybean genotypes showed varying seedling root growth responses to soil WLIS, while shoot biomass characteristics were similar.

Soybean

Soybean PDF Author: Minobu Kasai
Publisher: BoD – Books on Demand
ISBN: 1789853737
Category : Technology & Engineering
Languages : en
Pages : 192

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Book Description
Plants are important for a permanent ecosystem, because in the ecological pyramid plants support all the other living organisms at the base. Very important organization is thought to be the integral process of resource, transport, partitioning, metabolism, and production, which involves yield, biomass, and productivity in plants. Accordingly, it is important to obtain more information about the knowledge concerning yield, biomass, and productivity in plants. Soybean is one of the main crops largely contributing to our life, which is thought to be connected to our ecosystem through the above-mentioned integral process. This book focuses on the soybean, and reviews and research concerning the yield, biomass, and productivity of soybean are presented herein. This text updates the book published in 2017. Although there are many difficulties, the main aim of this book is to present a basis for the above-mentioned integral processes of resource, transport, partitioning, metabolism, and production, which involves yield, biomass, and productivity in plants (soybean), and to understand what supports this basis and the integral process. It is hoped that this and the preceding book will be essential reads.

Evaluation of Soybean (Glycine Max L. Merr.) Root Development in Greenhouse Solution Culture and the Relationship to Drought Tolerance in the Field

Evaluation of Soybean (Glycine Max L. Merr.) Root Development in Greenhouse Solution Culture and the Relationship to Drought Tolerance in the Field PDF Author: Lynn Liane Scherbert
Publisher:
ISBN:
Category :
Languages : en
Pages : 218

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Plasticity of Soybean (Glycine Max (l.) Merrill) Root Development Under Mild Water Deficits

Plasticity of Soybean (Glycine Max (l.) Merrill) Root Development Under Mild Water Deficits PDF Author: Yong He
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages :

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Book Description
Drought is the major abiotic factor limiting soybean yield in the US. Under water deficit conditions, root systems may exhibit developmental plasticity resulting in morphological changes that extend the water-absorbing surface area of the roots. The objective of this study was to identify soybean genotypes which exhibit genetic diversity in root system developmental plasticity in response to water deficits, in order to enable physiological and genetic analyses of the regulatory mechanisms involved. Studies were conducted both at the seedling stage under precisely-controlled water deficits, and during three-week soil drying treatments of plants growing in 1.5 m-deep soil cylinders in controlled-environment chambers. Using the seedling system, 11 soybean genotypes selected from both domestic and Plant Introduction lines were studied. The results showed substantial genetic diversity in the capacity for increased lateral root development (number and total length of roots produced) and in the responses of overall root and shoot growth under water deficit conditions. Studies of the spatial and temporal patterns of lateral root development showed that the promotion of lateral root length under water deficit conditions was due to an increased root production rate rather than earlier initiation or promotion of root elongation. Genotypes with either superior or inferior root plasticity responses at the seedling stage were selected for more detailed studies using the deeper soil cylinder system with more mature plants. The results showed consistent genetic differences in lateral root developmental plasticity under water deficit conditions between the seedling and more mature plant systems.

A Genotypic Comparison of Plasticity of Root System Development During Soil Drying in Soybean (Glycine Max (L.) Merrill)

A Genotypic Comparison of Plasticity of Root System Development During Soil Drying in Soybean (Glycine Max (L.) Merrill) PDF Author: Tracy Cottle Scanlan
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages :

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Book Description
Water deficit is responsible for significant losses in soybean (Glycine max (L.) Merrill) yield under dryland conditions. Under drought, increases in root depth and density, i.e., developmental plasticity, enable plants to sustain high rates of water extraction and help to maintain yield (O'Toole and Bland, 1987; Sponchiado et al., 1989; White and Castillo, 1989). The objective of this project was to screen and identify soybean lines exhibiting diversity in root system characteristics that are associated with drought tolerance, in order to enable physiological and genetic analyses of the regulatory mechanisms involved. A genetically diverse collection of soybean genotypes was selected for screening. To evaluate root plasticity in response to soil drying, an experimental system that allowed spatial and temporal monitoring of root proliferation was developed. Plants were grown in soil columns 1.5 meters in depth, and subjected to soil drying for three weeks. The vertical distribution of root development was monitored photographically at weekly intervals, and plants were harvested at the end of the experiments for taproot length and shoot biomass. In nine genotypes tested under greenhouse conditions, final taproot length ranged from 98% to 150% of well-watered controls. Genetic variation in the response of rooting density to drought was also demonstrated. However, comparison between genotypes was complicated by variation in leaf area development and, as a result, in rates of soil drying and plant stress development, as well as by seasonal variation in the greenhouse environmental conditions. Therefore, growth chamber studies which allowed equivalent rates of soil drying between two selected genotypes were conducted. These studies demonstrated that under equivalent rates of soil drying, insignificant differences in the response of rooting density to drought between the two genotypes were observed.

A Comprehensive Survey of International Soybean Research - Genetics, Physiology, Agronomy and Nitrogen Relationships

A Comprehensive Survey of International Soybean Research - Genetics, Physiology, Agronomy and Nitrogen Relationships PDF Author: James E. Board
Publisher:
ISBN: 9789535142591
Category : Chemistry, Technical
Languages : en
Pages : 626

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Book Description
Soybean is the most important oilseed and livestock feed crop in the world. These dual uses are attributed to the crop's high protein content (nearly 40% of seed weight) and oil content (approximately 20%); characteristics that are not rivaled by any other agronomic crop. Across the 10-year period from 2001 to 2010, world soybean production increased from 168 to 258 million metric tons (54% increase). Against the backdrop of soybean's striking ascendancy is increased research interest in the crop throughout the world. Information in this book presents a comprehensive view of research efforts in genetics, plant physiology, agronomy, agricultural economics, and nitrogen relationships that will benefit soybean stakeholders and scientists throughout the world. We hope you enjoy the book.

Genetic Variation for Physiological Traits Affecting Drought Tolerance Among Ontario-adapted Commercial Soybean [Glycine Max (L.) Merr.] Varieties Grown in 1-m Rooting Columns

Genetic Variation for Physiological Traits Affecting Drought Tolerance Among Ontario-adapted Commercial Soybean [Glycine Max (L.) Merr.] Varieties Grown in 1-m Rooting Columns PDF Author: Michael Gebretsadik Gebre
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Drought stress significantly limits soybean production in Ontario. Identification of physiological traits to improve drought tolerance in soybean would benefit from controlled-environment phenotyping methods. It was hypothesized that elite Ontario-adapted soybean varieties would differ for drought tolerance. A greenhouse culture system was developed employing 1-m rooting columns filled with amended field soil, that presents field-like volumetric soil water content and rooting profiles by depth. Different levels of drought stress were simulated in this system by restoring soil water to 100% (control), 75% (mild stress) or 50% (drought stress) of the maximum soil water holding capacity by daily weighing and watering from first flower (R1) until maturity. The effect of applying fertilizer throughout the 1-m soil profile instead of confining it to the upper 30 cm was tested. Distributing fertilizer over the entire 1-m rooting depth resulted in deeper rooting and more soil water extraction at depth at the R1 stage; however, these effects did not persist until maturity and so did not affect drought tolerance. Fifteen Ontario-adapted commercial soybean varieties were compared for their drought tolerance, defined as the ratio of their seed yield under drought conditions compared to control conditions (seed yield ratio; SYR). Similar to the effects of drought in the field, pod number was by far the yield component most affected, with effects on seeds per pod and single-seed weight being relatively minor. Based on their SYR, two drought-sensitive varieties (Saska and OAC Drayton) and three drought-tolerant varieties (OAC Lakeview, OAC Champion, and PRO 2715R) were identified. Principal components analysis showed that drought-tolerant varieties were those that maintained relatively high water use, shoot dry matter, and pod number under stress. Varieties differed for root biomass distribution by depth, but not for soil water extraction profiles, and there was no evidence that differences in drought tolerance were associated with rooting traits among these fifteen varieties. This study helps define the physiological basis of soybean variety differences in drought tolerance, and provides novel phenotyping tools for soybean breeders to select for root function and yield formation traits that could improve soybean yield under drought stress.

High Throughput Profiling of Transcription Factors Involved in Soybean Root Growth Under Water Deficit

High Throughput Profiling of Transcription Factors Involved in Soybean Root Growth Under Water Deficit PDF Author: Huong Nguyen Thanh Tran
Publisher:
ISBN:
Category : Deficit irrigation
Languages : en
Pages : 100

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Book Description
Drought is the major abiotic stress factor limiting crop productivity worldwide. Plant root and shoot systems respond to environmental changes by altering the expression of complex gene networks through sensing environmental stresses and modifying signaling and metabolic pathways. Previous work (Yamaguchi et al., 2009) showed that the soybean primary root adapts to low water potential ( -1.6 MPa) by maintaining longitudinal expansion in the apical 4 mm (region 1), whereas in the adjacent 4 mm (region 2), longitudinal expansion reaches a maximum in well-watered roots but is progressively inhibited at low water potential. To identify the key transcription factors (TFs) that determine these responses to low water potential, we have conducted high-throughput profiling of root-related TF expression in regions 1 and 2 of water-stressed and well-watered roots using quantitative real-time PCR. 186 root- and stress-related TFs were selected to identify their specific expression patterns in root regions 1 and 2 of well-watered and water-stressed soybean seedlings at four time points (5h, 12h, 24h, and 48h) after transplanting. Several stress-specific and root-region-specific transcripts were identified which may contribute to root responses to water deficits. Among these were zinc-finger protein, MYB-related protein, GmNAC3, GmNAC4, and bZIP transcription factors. These TFs were differentially expressed in distinct root regions, and therefore they can be targeted for functional characterization and further genetic engineering for enhanced drought resistance in soybean.

Plant, Abiotic Stress and Responses to Climate Change

Plant, Abiotic Stress and Responses to Climate Change PDF Author: Violeta Andjelkovic
Publisher: BoD – Books on Demand
ISBN: 1789231221
Category : Medical
Languages : en
Pages : 188

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Book Description
Climate change is a serious problem influencing agricultural production worldwide and challenging researchers to investigate plant responses and to breed crops for the changed growing conditions. Abiotic stresses are the most important for crop production, affecting about 96.5% of arable land worldwide. These stress factors include high and low temperature, water deficit (drought) and flooding, salinity, heavy metals, UV radiation, light, chemical pollutants, and so on. Since some of the stresses occurred simultaneously, such as heat and water deficit, causing the interactions of physiological processes, novel multidisciplinary solutions are needed. This book provides an overview of the present state in the research of abiotic stresses and molecular, biochemical, and whole plant responses, helping to prevent the negative impact of global climate change.

Emergence, Seedling Growth, and Area of Influence of Weeds Common in Soybeans (Glycine Max)

Emergence, Seedling Growth, and Area of Influence of Weeds Common in Soybeans (Glycine Max) PDF Author: David W. Monks
Publisher:
ISBN:
Category : Soybean
Languages : en
Pages : 272

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Book Description