In the Name of Allah the Most Beneficent the Most Merciful
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IN THE NAME OF ALLAH THE MOST BENEFICENT THE MOST MERCIFUL DEMOGRAPHY AND SEASONAL ECOPHYSIOLOGY OF A LEAF SUCCULENT HALOPHYTE SALSOLA DRUMMONDII ULBRICH. AYSHA RASHEED Institute of Sustainable Halophyte Utilization (ISHU) University of Karachi Karachi-75270, Pakistan 2014 DEMOGRAPHY AND SEASONAL ECOPHYSIOLOGY OF A LEAF SUCCULENT HALOPHYTE SALSOLA DRUMMONDII ULBRICH. THESIS SUBMITTED TO THE FACULTY OF SCIENCE UNIVERSITY OF KARACHI, IN THE FULFILLMENT OF THE REQUIREMENT FOR THE DEGREE OF DOCTOR OF PHILOSOPHY AYSHA RASHEED Institute of Sustainable Halophyte Utilization (ISHU) University of Karachi Karachi-75270, Pakistan 2014 Acknowledgements I am deeply indebted to my adviser, Prof. Dr. Bilquees Gul for her unwavering support, encouragement, stimulating insights, patience and guidance during the research work and thesis writing. I feel honored to be her first Ph.D. student. I am also thankful for the excellent example she has provided as a successful woman botanist and professor. I feel great pleasure to express my deep sense of gratitude to Prof. Dr. M. Ajmal Khan, for his guidance and continuous support from the very beginning of this research. I am also grateful to him for patiently reviewing and editing the dissertation. His dynamic personality, immense knowledge and devotion to pursue high quality research make him a great mentor. Special thank is due to Dr. Salman Gulzar for his generous help during the field work and valuable comments on my dissertation. He has been supportive since the days I began my research work. I am extremely grateful to Prof. Dr. Hans-Werner Koyro (Institute of Plant Ecology, Justus Liebig University, Giessen, Germany) for his sincere guidance, thought-provoking discussions and suggestions during this study. I am also thankful to Dr. Irfan Aziz, Dr. Raziuddin Ansari and Dr. M. Zaheer Ahmed for their encouragement throughout this work. I would like to acknowledge the “Higher Education Commission of Pakistan” for providing the Ph.D. merit scholarship (Indigenous Scholarship Program, Batch IV). I am thankful to all my colleagues and friends for their moral support and help especially Mr. Zainul Abideen, Mr. Tabassum Hussain, Mr. Haibat Ali, Mr. M. Qasim, Ms. Sarwat Ghulam Rasool, Ms. Sadaf Asif and of course Ms. Mishal Birgees Khan for her sweet company and friendship. Thanks are also due to Mr. Irfanuddin and Mrs. Saira Salman for their assistance in office related issues and Mr. Sawa Khan (Lab attendant) for his help during field work. Words are lacking to express my profound gratitude to my beloved brother Dr. Abdul Hameed for his help, support, encouragement, and love. I would also like to thank my younger brother Abdul Haseeb, for his love and support. With a deep emotion of gratitude, I dedicate this thesis to the memories of my grandfather Abdul Rauf, who is not amongst us now but his love and prayers made me what I am today. Last but not the least I would extend my deepest gratitude to my father Abdul Rasheed and mother Kishwar Rasheed for their love, continuous prayers, untiring support and encouragement during this research and throughout my life. I always feel the strength of their love and prayers in all the achievements I have made and it will remain with me during my whole life. Thank You Table of Contents Page Table of Contents I List of Tables III List of Figures V List of Abbreviations X Summary in English XIII Summary in Urdu XV Chapter 1 General introduction 1 References 15 Chapter 2 Effects of salinity, temperature, light and dormancy 27 regulating chemicals on seed germination of Salsola drummondii Abstract 28 Introduction 29 Materials and methods 31 Results 34 Discussion 42 References 47 Chapter 3 Variation in temperature and light but not salinity 54 invoke antioxidant enzyme activities in germinating seeds of Salsola drummondii Abstract 55 Introduction 56 I Materials and methods 57 Results 60 Discussion 71 References 75 Chapter 4 Growth, oxidative damage and antioxidant enzyme 84 activities in NaCl-treated seedlings of Salsola drummondii Abstract 85 Introduction 86 Materials and methods 87 Results 90 Discussion 98 References 102 Chapter 5 Physiological responses of Salsola drummondii population 109 to seasonal variations Abstract 110 Introduction 111 Materials and methods 113 Results 117 Discussion 133 References 137 Chapter 6 General Conclusion 145 II List of Table Page Table 2.1: Two-way analysis of variance (ANOVA) indicating significance of the 34 individual and collective effects of various experimental factors on the percentage of germinated (G), recovered (R), viable (V) and dead (D) seeds when recovered from salt. Where, numbers represent F-values. * = P < 0.05 and *** = P < 0.001. Table 2.2: Two-way analysis of variance (ANOVA) indicating significance of the 35 individual and collective effects of various experimental factors on the percentage of germinated (G), recovered (R), viable (V) and dead (D) seeds when recovered from temperature. Where, numbers represent F- values. * = P < 0.05, ** = P < 0.01, *** = P < 0.001 and ns = non- significant. Table 2.3: Two-way analysis of variance (ANOVA) indicating significance of the 35 individual and collective effects of various experimental factors on the percentage of germinated (G), recovered (R), viable (V) and dead (D) seeds when recovered from dark. Where, numbers represent F-values. * = P < 0.05, ** = P < 0.01, *** = P < 0.001 and ns = non-significant. Table 3.1: Seed characteristics of Salsola drummondii. 60 Table 3.2: Analysis of variance showing the effect of different abiotic factors on 61 percent germination (G), relative water uptake (RWU), MDA content and antioxidant enzyme activities of Salsola drummondii seeds. Values represent F- values. Where, * = P < 0.05; ** = P < 0.01; *** = P < 0.001 and ns = non-significant. Table 4.1: Analysis of variance showing the effect of different NaCl treatments at 91 20/30 oC in 12-H light on various growth parameters and antioxidant enzyme activities in seedlings of Salsola drummondii. Values represent F- values. Where, * = P < 0.05; ** = P < 0.01; *** = P < 0.001 and ns = non-significant. III Table 5.1: Description of sampling time. 114 Table 5.2: Two-way analysis of variance (ANOVA) of soil cation content due to seasons 119 (S), soil depth (D) and S x D interactions on the soil mineral content of the Salsola drummondii community. Numbers indicate F-values at * = P < 0.05, ** = P < 0.01, *** = P < 0.001 and ns = non-significant. Table 5.3: Seasonal variations in the soil cations (Na+, K+, Ca++ and Mg++; mg Kg-1 DW) 120 contents drawn from different depths of the Salsola drummondii community. Table 5.4: Summary of F-values from one way analysis of variance (ANOVA) in growth 124 and physiological parameters of Salsola drummondii during the study year. Table 5.5: Seasonal variations in the photosynthetic pigments and gas exchange 131 parameters of Salsola drummondii. IV List of Figures Page Figure 1.1: Salsola drummondii in its habitat. 9 Figure 1.2: Google Earth image of the study site. 9 Figure 1.3: Economic importance of Salsola drummondii. 10 Figure 1.4: Phenology diagram of Salsola drummondii in salt desert of Balochistan, 11 Pakistan. Figure 1.5: Conceptual flow diagram of seed bank dynamics for Salsola drummondii 12 growing in the salt deserts of Balochistan, Pakistan. Figure 1.6: Parts of this PhD thesis in which the role of Salsola drummondii under 14 natural habitat conditions and its ecological requirements and ecophysiological responses were studied in the context of 1). Germination ecology, biochemistry and seedling growth and 2). Seasonal eco- physiology. Figure 2.1: Effect of salt, light/dark and temperature treatments on the seed 36 germination of Salsola drummondii. A. 10/20 ◦C, B. 15/25 ◦C, C. 20/30 ◦C and D. 25/35 ◦C. Circles represent mean ± standard errors. F- Values were obtained from analysis of variance (ANOVA) by using L (light/dark treatments) and S (NaCl treatments). Where, * = P < 0.05; ** = P < 0.01 *** = P < 0.001 and ns = non-significant. Figure 2.2: Effect of salt, light/dark and temperature treatments on the rate of seed 37 germination of Salsola drummondii. A. 10/20 ◦C, B. 15/25 ◦C, C. 20/30 ◦C and D. 25/35 ◦C. Each circle represents mean ± standard errors. Symbols having same letter within each salt treatment are not significantly different (P < 0.05) among means (Bonferroni test). F- values were obtained from Analysis of variance (ANOVA) by using S (NaCl treatments). Where, *** V = P < 0.001. Figure 2.3: Percentage of germinated ( ), recovered ( ), viable 39 ( ) and dead ( ) seeds of Salsola drummondii treated with various concentrations of NaCl under 12-H photoperiod. Figure 2.4: Percentage of germinated ( ), recovered ( ), viable 40 ( ) and dead ( ) seeds of Salsola drummondii treated with different temperatures under 24-H dark. Figure 2.5: Effects of GA3 (10 µM), GA4, (10 µM), GA4+7 (10 µM), thiourea(100 µM), 41 kinetin (3 mM) and fussicoccin (5 µM) on mean final germination of S. drummondii seeds in 12-H photoperiod (A), 24-H dark (C) and rate of germination (E) under control (0 mM NaCl) and saline condition (800 mM NaCl). Relative changes (folds) due to DRCs in mean final germination of S. drummondii seeds in 12-H photoperiod (B), 24-H dark (D) and rate of germination (F) are also given in comparison to respective non-saline and saline controls. Bars represent mean ± standard errors. Bars having same letter within each salt treatment are not significantly different (P < 0.05) among means (Bonferroni test). Asterisk (*) indicates significant (P < 0.05) difference between a DRC treatment and saline control (t-test). Figure 3.1: Effect of A) salinity, B) temperature and C) light on the percent 62 germination in seeds of Salsola drummondii. Bars represent mean ± standard error.