This study consisted of four experiments conducted in the greenhouse of Biology Department in the College of Science- University of Salahaddin- Erbil, during 18/4/ 2012 to 28/7/2012. The first experiment consisted of foliar spray of different concentrations of Salicylic acid (0, 50, 100, 200 and 400ppm), the second experiment included the application of different methods of Salicylic acid (250ppm) (presoaking seeds, foliar spray, injection, and soil application). The third experiment consisted of different concentrations of Lead (0, 5, 10, 15 and 20ppm) as soil irrigation, and the fourth experiment consisted of interaction application of Salicylic acid and Lead on vegetative growth, yield and chemical components of common bean. The results obtained were analyzed statistically using Complete Randomized Design (C.R.D) for the first three experiments and Factorial Complete Randomized Design (Factorial C.R.D) for the fourth experiment, with four replications for each treatment. Comparison of means were carried out by using Duncan’s Multiple Range Test at the probability of (0.05) for vegetative and yield parameters and (0.01) for the chemical constituents.
Table of Contents
1 Introduction
2 Review of Literature
2.1 Effects of SA
2.1.1 Historical discovery of SA
2.1.2 Effect of SA on vegetative growth
2.1.3 Effect of SA on yield characteristics
2.1.4 Effect of SA on chemical characteristics
2.2 Effects of Pb
2.2.1 Effect of Pb on vegetative growth
2.2.2 Effect of Pb on yield characteristics
2.2.3 Effect of Pb on chemical characteristics
2.3 Interaction effects of SA and Pb
3 Materials and methods
3.1 Location
3.2 Preparation of the soil and pots
3.3 Preparation of SA solutions
3.4 Preparation of Pb solutions
3.5 Description of glass house experiments
3.5.1 Experiment (1): Effect of different concentrations of SA on growth and development of bean plant
3.5.2 Experiment (2): Effect of SA applied by different methods on growth and development of bean plant
3.5.3 Experiment (3): Effect of different concentrations of Pb on growth and development of bean plant
3.5.4 Experiment(4):Interaction effect of different concentrations of SA and Pb on growth and development of bean plant
3.6 Statistical analysis
3.7 Experimental parameters
3.7.1 Vegetative growth parameters
3.7.1.1 Plant height (cm)
3.7.1.2 Number of branches.plant-1
3.7.1.3 Number of leaves.plant-1
3.7.1.4 Leaf area (cm2).plant-1
3.7.1.5 Dry weight of shoot system (g.plant-1)
3.7.2 Yield components
3.7.2.1 Number of pods.plant-1
3.7.2.2 Number of seeds.pod-1
3.7.2.3 Dry weight of 100 seeds (g)
3.7.3 Chemical analysis of leaves and seeds
3.7.3.1 Chlorophyll content (mg.g-1 fresh weight)
3.7.3.2 Water content (g.plant-1)
3.7.3.3 Total protein (%)
3.7.3.4 Proline determination ( μg.g-1 fresh weight)
3.7.3.5 Total phenol determination (μg.g-1 fresh weight)
3.7.3.6 Total carbohydrates (%)
3.7.4 Mineral nutrient contents in dry weight
3.7.4.1 Total nitrogen ( mg.g-1 )
3.7.4.2 Total phosphorus (mg.g-1)
3.7.4.3 Total potassium (K+) and sodium (Na+) (mg.g-1)
3.7.4.4 Total calcium, magnesium (mg.g-1), zinc ,manganese and iron contents (μg.g-1)
3.7.4.5 Total Pb contents in plant and soil (μg.g-1)
3.7.5 Preparation of stomatal slide
4 Results
4.1 Experiment (1): Effect of different concentrations of SA on growth and development of bean plant
4.1.1 Vegetative growth characteristics
4.1.1.1 Plant height (cm)
4.1.1.2 Number of leaves .plant-1
4.1.1.3 Number of branches .plant-1
4.1.1.4 Dry weight of shoot system (g.plant-1)
4.1.1.5 Leaf area (cm2).plant-1
4.1.2 Yield characteristics
4.1.2.1 Number of pods .plant-1
4.1.2.2 Number of seeds .pod -1
4.1.2.3 Dry weight of 100 seeds (g)
4.1.3 Chemical characteristics of seeds and leaves
4.1.3.1 Biochemical contents
4.1.3.1.1 Chlorophyll contents of leaves (mg.g-1fresh weight )
4.1.3.1.2 Total protein contents of leaves (%)
4.1.3.1.3 Total carbohydrate content of seeds (%)
4.1.3.2 Mineral nutrient contents of leaves
4.1.3.2.1 Total nitrogen (mg.g-1)
4.1.3.2.2 Total phosphorus (mg.g-1)
4.1.3.2.3 Total potassium (mg.g-1)
4.1.3.2.4 Total calcium (mg.g-1)
4.1.3.2.5 Total sodium (mg.g-1)
4.1.3.2.6 Total magnesium (mg.g-1)
4.1.3.2.7 Total manganese (μg.g-1)
4.2 Experiment(2): Effect of different methods of SA application on growth and development of bean plant
4.2.1 Vegetative growth characteristics
4.2.1.1 Plant height (cm)
4.2.1.2 Number of leaves .plant-1
4.2.1.3 Number of branches .plant-1
4.2.1.4 Dry weight of shoot system (g.plant-1)
4.2.2 Yield characteristics
4.2.2.1 Number of pods. plant -1
4.2.2.2 Number of seeds .plant-1
4.2.2.3 Dry weight of 100 seeds (g)
4.2.3 Chemical characteristics of seeds and leaves
4.2.3.1 Biochemical contents
4.2.3.1.1 Chlorophyll contents of leaves (mg.g-1fresh weight)
4.2.3.1.2 Total protein contents of leaves (%)
4.2.3.1.3 Total carbohydrate of seeds (%)
4.2.3.2 Mineral nutrient contents of leaves
4.2.3.2.1 Total nitrogen(mg.g-1)
4.2.3.2.2 Total phosphorus(mg.g-1)
4.2.3.2.3 Total potassium (mg.g-1)
4.2.3.2.4 Total calcium(mg.g-1)
4.2.3.2.5 Total sodium (mg.g-1)
4.2.3.2.6 Total magnesium(mg.g-1)
4.2.3.2.7 Total manganese (μg.g-1)
4.3 Experiment (3): Effect of different concentrations of Pb on growth and development of bean plant
4.3.1 Vegetative growth characteristics
4.3.1.1 Plant height (cm)
4.3.1.2 Number of leaves .plant -1
4.3.1.3 Number of branches .plant-1
4.3.1.4 Dry weight of shoot system (g.plant1)
4.3.2 Yield characteristics
4.3.2.1 Number of pods.plant-1
4.3.2.2 Number of seeds.pod-1
4.3.2.3 Dry weight of 100 seeds(g)
4.3.3 Chemical characteristics of leaves and seeds
4.3.3.1 Biochemical contents
4.3.3.1.1 Chlorophyll contents of leaves (mg.g-1 fresh weight)
4.3.3.1.2 Water contents of shoot system (g.plant-1)
4.3.3.1.3 Total protein contents of leaves (%)
4.3.3.1.4 Total carbohydrate contents of seeds (%)
4.3.3.1.5 Proline contents of leaves (μg.g-1 fresh weight)
4.3.3.1.6 Total phenol content of leaves ( μg.g-1 fresh weight)
4.3.3.2 Mineral nutrient contents of leaves
4.3.3.2.1 Total nitrogen (mg.g-1)
4.3.3.2.2 Total phosphorus (mg.g-1)
4.3.3.2.3 Total potassium and sodium (mg.g-1)
4.3.3.2.4 Total calcium (mg.g-1)
4.3.3.2.5 Total magnesium (mg.g-1) and manganese (μg.g-1)
4.3.3.2.6 Total iron and zinc (μg.g-1)
4.3.3.2.7 Total lead content (μg.g-1)
4.3.4 Stomatal characteristics
4.3.4.1 Number of closed stomata .unit of area -1
4.3.4.2 Total number of stomata .unit of area -1
4.4 Experiment (4): Interaction effects of SA and Pb on growth and development of bean plant
4.4.1 Vegetative growth characteristics
4.4.1.1 Plant height (cm)
4.4.1.2 Number of leaves .plant-1
4.4.1.3 Number of branches .plant-1
4.4.1.4 Dry weight of shoot system (g.plant-1)
4.4.2 Yield characteristics
4.4.2.1 Number of pods.plant-1
4.4.2.2 Number of seeds .pod-1
4.4.2.3 Dry weight of 100 seeds (g)
4.4.3 Chemical characteristics of seeds and leaves
4.4.3.1 Biochemical contents
4.4.3.1.1 Chlorophyll contents of leaves (mg.g-1fresh weight)
4.4.3.1.2 Water content of shoot system (g.plant-1)
4.4.3.1.3 Total protein content of leaves (%)
4.4.3.1.4 Total carbohydrate content of seeds (%)
4.4.3.1.5 Proline content of leaves (μg.g-1 fresh weight)
4.4.3.1.6 Total phenol contents of leaves (μg.g-1 fresh weight)
4.4.3.2 Mineral nutrient contents of leaves
4.4.3.2.1 Total nitrogen (mg.g-1)
4.4.3.2.2 Total phosphorus (mg.g-1)
4.4.3.2.3 Total potassium (mg.g-1)
4.4.3.2.4 Total calcium (mg.g-1)
4.4.3.2.4 Total sodium (mg.g-1)
4.4.3.2.5 Total magnesium (mg.g-1)
4.4.3.2.6 Total manganese (μg.g-1)
4.4.3.2.7 Total zinc (μg.g-1)
4.4.3.2.8 Total iron (μg.g-1)
4.4.3.2.9 Total lead content (μg.g-1)
5 Discussion
6 Conclusions and recommendations
7 References
8 Appendices
Research Objectives and Key Themes
The primary research objective of this thesis is to investigate the independent and combined effects of Salicylic acid (SA) and Lead (Pb) on the vegetative growth, yield components, and chemical composition of the common bean plant (Phaseolus vulgaris L.). Furthermore, the study aims to evaluate the potential of SA to alleviate the negative physiological and biochemical stress induced by lead toxicity.
- The role of Salicylic acid as an endogenous growth regulator in plant development.
- The inhibitory impact of heavy metal (Lead) stress on plant physiology and mineral nutrition.
- The regulatory mechanisms of SA-Pb interaction under greenhouse conditions.
- Statistical analysis of growth parameters, yield components, and biochemical constituents (e.g., chlorophyll, protein, proline, total phenol).
- The efficacy of different SA application methods (presoaking, foliar, soil, injection).
Excerpt from the Thesis
1. Introduction
The Common Bean (Phaseolus vulgaris L.) is a herbaceous annual plant species, belongs to fabaceae family domesticated independently in ancient Mesoamerica and now grown worldwide both for dry beans and as green bean. Among major food legumes the Common Bean is the third most important worldwide, superseded only by Soybean [Glycine max (L.) Merr.], and Peanut (Arachis hypogaea L.) (Zeka, 2007). The common bean grown for their tender and green pods, or seeds as an important source of protein (20–25%) and complex carbohydrates (50–60%) (Martiniz et al., 2011), dietary fiber, minerals such as iron, zinc, calcium, and phosphorus and vitamins (Carvalho et al., 2012).
Phenolics are compounds possessing one or more aromatic rings with one or more hydroxyl groups (Michalak, 2006). Salicylic acid (SA) is an endogenous growth regulator of phenolic nature, which participates in the regulation of physiological processes in plants. SA has been found to play a key role in the regulation of plant growth, development, and interaction with other factors and in the responses to environmental stresses. Furthermore, it’s role is evident in seed germination, plant growth, fruit yield, glycolysis, flowering, ion uptake and transport, photosynthetic rate, stomatal conductance and transpiration …etc (Sadeghipour and Aghaei, 2012 A, B). It is implicated in hardening response to a biotic stressors and mediates some positive acclimination response to a biotic stress, such as heavy metals, herbicides, low temperature, salinity (Mohsenzadeh et al., 2011), and osmotic stress. Along these stresses, toxic heavy metal stress is an emerging and more effective stress for major crops (Bhardwaj et al., 2009).
Summary of Chapters
1 Introduction: Provides an overview of the significance of the common bean, the role of SA as a plant growth regulator, and the toxic effects of heavy metals like lead on plant development.
2 Review of Literature: Details previous scientific studies regarding the physiological and chemical effects of salicylic acid and lead on plant growth and yield, as well as existing knowledge on their interactions.
3 Materials and methods: Outlines the four specific experiments conducted, including the preparation of soil, chemical solutions, greenhouse procedures, and the analytical methods used to measure growth and chemical parameters.
4 Results: Presents the statistical data gathered from the four experiments regarding the impact of SA application and lead stress, both individually and in combination, on various plant traits.
5 Discussion: Analyzes the observed results by comparing them with findings from existing literature, interpreting how SA modulates lead stress through physiological and biochemical pathways.
6 Conclusions and recommendations: Summarizes the key findings, confirming the positive role of SA in alleviating heavy metal toxicity, and suggests further field-based research.
Keywords
Common Bean, Phaseolus vulgaris L., Salicylic acid, Lead toxicity, Vegetative growth, Yield components, Chlorophyll, Protein content, Proline, Heavy metal stress, Mineral nutrition, Phytotoxicity, Greenhouse experiments, Plant physiology, Stomatal characteristics.
Frequently Asked Questions
What is the core subject of this research thesis?
The research explores the impact of salicylic acid and lead on the growth, development, and physiological performance of the common bean (Phaseolus vulgaris L.).
What are the primary themes addressed in the work?
The primary themes include plant growth regulation, heavy metal toxicity, alleviation strategies for abiotic stress, and biochemical changes in plant leaves and seeds.
What is the overarching research goal?
The study aims to determine if exogenous salicylic acid can mitigate the growth-inhibiting effects of lead toxicity in common bean plants grown in controlled greenhouse environments.
What scientific methods were employed to gather the results?
The research involved four distinct greenhouse experiments analyzed via Complete Randomized Design (C.R.D) and Factorial C.R.D, with mean comparisons using Duncan’s Multiple Range Test and data processing via SPSS software.
What information is covered in the main body of the work?
The main body focuses on the vegetative growth characteristics, yield components, chemical composition of leaves and seeds, and the statistical interactions between various lead concentrations and salicylic acid treatments.
Which keywords are essential for understanding this work?
Keywords include Common Bean, Salicylic acid, Lead toxicity, plant growth, mineral nutrition, and chlorophyll content.
How does lead affect the stomatal characteristics of the common bean?
The study found that lead application led to an increase in the number of closed stomata while simultaneously decreasing the total number of stomata in the upper epidermis.
What specific interaction effects were discovered regarding protein content in leaves?
Interaction analysis revealed that salicylic acid treatments helped to decrease the negative effects of lead, with specific concentrations such as Pb10SA100 and Pb10SA400 significantly increasing total protein content in leaves.
- Citar trabajo
- Halala Qader (Autor), 2013, Effect of Salicylic acid, Lead and their interaction on growth and development of (Phaseolus vulgaris L.) plants, Múnich, GRIN Verlag, https://www.grin.com/document/282593
