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Thesis Details
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TITLE
DEDICATION
DECLARATION
CERTIFICATE
ACKNOWLEDGEMENT
CONTENTS
ABBREVIATIONS
List of tables
LIST OF FIGURES
1. Introduction
1.1 Rubber tree -- An eco-friendly source of timber
1.2 Availability of rubber wood
1.3 Commercial utilization of rubber wood
1.3.1 The Indian scenario
1.4 Demerits of rubber wood
1.5 Relevance of the study
2. Review of literature
2.1 Structural features of rubber wood
2.1.1 Gross structure
2.1.2 Anatomy of rubber wood
2.2 Major demerits of rubber wood
2.2.1 Susceptibility to biological deterioration
2.2.2 Tension wood -- a natural defect
2.3 Structure of tension wood fibres
2.4 Mechanism of tension wood formation
2.5 Tension wood formation in Hevea brasiliensis
2.6 Tension wood - wood working problems
3. Materials and methods
3.1 Distribution pattern, proportion and structure of tension wood in mature trees
3.1.1 Materials
3.1.2 Methodology
3.1.2.1 Collection of wood discs
3.1.2.2 Preparation of samples
3.1.2.3 Quantification of tension wood
3.2 Effect of leaning angle on tension wood formation in mature trees
3.3 Distribution pattern and proportion of tension wood in immature plants
3.4 Tension wood formation in bud grafted and non -bud -grafted (tissue culture) plants
3.5 Tension wood formation in tapped and untapped zones of the trunk
3.6 Tension wood formation and wind damage
3.7 Structural studies on tension wood
3.7.1 Dimension of fibres and vessel elements
3.7.2 Fibre wall thickness
3.7.3 Analysis of pores
3.7.4 Analysis of rays
3.8 Histochemical studies
3.9 Visual identification of tension wood in rubber wood logs
3.10 Factors affecting tension wood formation
3.10.1 Angle of leaning
3.10.2 Angle of leaning with defoliation
3.10.3 Effect of gravity on tension wood formation
3.10.4 Effect of growth regulators
3.10.4.1 Apical application of IAA, TIBA and GA3 on artificially bent plants
3.10.4.2 Lateral application of IAA, TIBA and GA3 on plants grown vertical
3.10.4.3 Lateral application of IAA on plants grown vertical through incision of bark
3.10.4.4 Lateral application of IAA and TIBA on plants under artificial bending
3.11 Statistical Analysis
3.12 Photography
1 Diagrammatic representation of collection wood discs from tree and preparation of samples
2 Tissue culture plant and budgrafted plant at the age of 8 months (clone R.RII 105)
3 Angle of leaning seedlings bent at 45° and 90°
4 Angle of leaning: seedling.bent at 135°
5 Angle of leaning with defoliation: seedlings bent at 45° and 90°
6 Angle of leaning with defoliation: seedling bent at 135° 7 Loop Experiment
7. Loop Experiment
8 Method of application of growth regulators on bent and vertically growing plants
9 Method of application of growth regulators on bent and vertically growing plants
4. Results
4.1 Distribution pattern and proportion of tension wood in mature trees
4.2 Distribution pattern and proportion of tension wood in immature plants
4.3 Tension wood formation in bud-grafted and non-budgrafted (tissue culture) plants
4.4 Effect of leaning angle on tension wood formation in mature trees
4.5 Tension wood formation in tapped and untapped zones of the trunk
4.6 Tension wood formation and wind damage
4.7 Visual identification of tension wood in rubber wood logs
4.8 Structural studies on tension wood
4.8.1 Fibres
4.8.1.1 Length of fibres
4.8.1.2 Width of fibres
4.8.1.3 Fibre wall thickness
4.8.2 Vessel elements
4.8.2.1 Length of vessel elements
4.8.2.2 Width of vessel elements
4.8.3 Analysis of pores
4.8.3.1 Number of pores
4.8.3.2 Total area occupied by pores
4.8.3.3 Average area of pores
4.8.4 Analysis of rays
4.8.4.1 Frequency of rays
4.8.4.2 Height of rays
4.8.4.3 Width of rays
4.8.4.4 Height / width ratio of rays
4.9 Histochemical studies
4.9.1 Starch
4.9.2 Cellulose
4.9.3 Lignin
4.9.4 Lipid
4.9.5 Total proteins
4.10 Factors affecting tension wood formation in Hevea
4.10. I Angle of leaning
4.10.1.1 Plants with foliage
4.10.1.2 Plants without foliage
4.10..2 Effect of gravity on tension wood formation
4.10.3 Effect of growth regulators on tension wood formation
4.10.3.1 Apical application of IAA, GA; and TIBA on artificially bent plants
4.10.3.1.1 Application of IAA
4.10.3.1.2 Application of GA;
4.10.3.1.3 Application of TIBA
4.10.3.1.4 Lanolin / Lanolin
4.10.3.2 Lateral application of IAA, GA3 and TIBA on vertically grown plants
4.10.3.2.1 IAA
4.10.3.2.2 GA3
4.10.3.2.3 TIBA
4.10.3.2.4 Lanolin (control)
4.10.3.3 Lateral application of IAA on plants grown vertical through incision of bark
4.10.3.4 Lateral application of IAA and TIBA on artificially bent step- axis at 45
4.10.3.4.1 IAA
4.10.3.4.2 TIBA
10 Cross-sawn discs of rubber wood showing white wooly arcs of compact tension wood (clones-: Tjir 1 & GT 1)
11 Cross-sawn disc of rubber wood showing white wooly arcs of compact tension wood (clones: RRIM 600 & RRII 105)
12 Distribution pattern and structure of tension wood and normal wood (clone Tjir I)
13 Distribution pattern and structure of tension wood and normal wood (clone GT 1)
14 Distribution pattern and structure of tension wood and normal wood (clone RRIM 600)
15 Distribution pattern and structure of tension wood and normal wood (clone RRII 105)
16 Proportion of tension wood in mature trees
17 Cross section of wood showing distribution of tension wood in ten month old budgrafted plants (clones: Tjir I, RRIM 703, PB 5 151 & RRIM 623)
18 Cross section of wood showing distribution of tension wood in ten month old budgrafted plants (clones: GT 1, RRIM 600, PB 217 & PB 235)
19 Cross section of wood showing distribution of tension wood in ten month old budgrafted plants (clones: RRII 105 & GI 1)
20 C.S. of wood showing distribution of tension wood in tissue culture plant and bud grafted plant
21 Tension wood formation and wind damage
22 Macroscopic stainingg of tension wood
23 Morphology of normal and tension wood fibres
24 Length of normal and tension wood fibres from pith to periphery
25 Width of normal wood and tension wood fibers from pith to periphery
26 Length of vessel elements from pith to periphery
27 Width vessel elements from pith to periphery
28 T.L.S. & T.S. of wood showing histochemical localization of starch and cellulose
29 Histochemical localization of lignin in tension wood and normal wood fibres
30 T.L.S. of wood showing localization of lipids T.L.S. of wood showing localization of total proteins
31 C.S of wood showing distribution of tension wood in four month old inclined and vertical seedlings
32 C.S. of wood showing distribution of tension wood in four month old defoliated, inclined and vertical seedlings
33 C.S. of wood showing distribution of tension wood in different segments of the loop
34 C. S. of wood from upper and lower halves of the bent axis treated with IAA and GA3
35 C.S. of wood from upper and lower halves of the bent axis treated with TIBA and lanolin (control)
36 C.S. of wood showing distribution of tension wood in vertical plants treated with lateral application of IAA, GA, and TIBA
37.C.S. of wood showing distribution of tension wood (arrows) in vertical and inclined slants treated with lateral application of IAA and TIBA
5. Discussion
5.1 Distribution pattern of tension wood in Hevea brasiliensis
5.2 Proportion of tension wood in mature trees
5.3 Proportion of tension wood in immature phase
5.4 Proportion of tension wood in bud-grafted and tissue culture plants
5.5 Directional effect of tree leaning on tension wood formation
5.6 Proportion of tension wood in tapped and untapped regions within trees
5.7 Tension wood formation and wind damage
5.8 Visual identification of tension wood
5.9 Structural studies on tension wood
5.9.1 Fibre length
5.9.2 Fibre width
5.9.3 Fibre wall thickness
5.9.4 Length and width of vessel elements
5.9.5 Number of pores
5.9.6 Total area occupied by pores
5.9.7 Average area of pores
5.9.8 Frequency of rays
5.9.9 height. width and height / width ratio of rays
5.10 Histochemical studies
5. 10. l Starch
5.10.2 Lipids
5.10.3 Total Proteins
5.10.4 Cellulose
5.10.5 Lignin
5.11 Factors affecting tension wood formation
5.11.1 Angle of leaning on tension wood formation
5.11.2 Defoliation on tension wood formation
5.11.3 Gravitational response on tension wood formation
5.11.4 Effect of growth regulators on tension wood formation
5.11.4.1 Indole accetic acid (IAA)
5.11.4.2 Gibberellic acid (GA3)
5.11.4.3 Tri-iodo benzoic acid (TIBA)
6. Summary
References