NADEEM AHMAD PLANT BREEDING AND GENETICS

205 Pages·2017·3.45 MB·English

GENETICS OF DROUGHT TOLERANCE IN
WHEAT (Triticum aestivum L.)

By

NADEEM AHMAD
M. Sc. (Hons) Agri
93-ag-1304

A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE

REQUIREMENT OF THE DEGREE OF

DOCTOR OF PHILOSOPHY
IN

PLANT BREEDING AND GENETICS

DEPARTMENT OF PLANT BREEDING AND GENETICS
FACULTY OF AGRICULTURE
UNIVERSITY OF AGRICULTURE, FAISALABAD
(PAKISTAN)
2016
Declaration

I hereby declare that contents of the thesis “Genetics of drought
tolerance in wheat (Triticum aestivum L.)” are product of my own research
and no part has been copied from any published source (except the references,
standard mathematical or genetic models/equations /formulae/ protocols etc.).
I further declare that this work has not been submitted for award of any other
diploma/degree. The university may take action if the information provided is
found inaccurate at any stage. (In case of any default, the scholar will be
proceeded against as per HEC plagiarism policy).

NADEEM AHMAD
93-ag-1304

DEDICATED
To
Those who struggled their best
for hunger elimination through
the attainment of food security
in the world
ACKNOWLEDGEMENTS

Foremost, innumerable thanks to ALMIGHTY ALLAH, Whose unlimited and
unpredictable source of help made me able to win honors of life. It is one of the infinite
blessings of ALLAH that he bestowed me with potential and ability to complete the present
research. Countless salutations be upon the holy Prophet MUHAMMAD (peace be upon
him) who demonstrated and taught the highest values of humanity to mankind and guided his
“UMMAH” to seek knowledge from cradle to grave.
I owe a great depth of gratitude and appreciation to my supervisor Professor Dr.
Abdus Salam Khan, Chairman, Department of Plant Breeding and Genetics, University of
Agriculture, Faisalabad for his guidance and affectionate attitude during the whole course of
my study. I’m also very gratified to my committee members; Dr. Ihsan Khaliq, Professor,
Department of Plant Breeding and Genetics & Dr. Muhammad Ayub, Professor,
Department of Agronomy, University of Agriculture, Faisalabad for their polite and kind
hearted behavior and valuable instructions throughout the period of my research.
Words alone cannot express the gratitude and appreciation I have for Dr. Zulfiqar
Ali, Associate Professor, Department of Plant Breeding and Genetics, University of
Agriculture, Faisalabad for his guidance and affection. I also wish to acknowledge Dr.
Muhammad Ahsan, Associate Professor and Dr. Amir Shakeel, Assistant Professor,
Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad for their
valuable suggestions and co-operation.
I extend my sincere thanks to Dr. Aziz-ur-Rehman Lentil Botanist, Pulses
Research Institute and Dr. Jehanzeb Farooq, Assistant Research Officer, Cotton Research
Institute, Ayub Agriculture Research Institute, Faisalabad who helped me during the
conduct of my research work. Without their help, I would have never accomplished what I
have today.
My deepest love and affection for my little angels; Faheem , Khalil and Aaleya, as
their innocence was a source of power for me. I also have no words to thank my Brothers
and Sisters for their prayers.
I pay my cordial thanks to those whose love will never mitigate, whose prayers will
never die, who are nearest, deepest and dearest to me, my Parents.
May ALLAH bless them all in all the worlds (Aameen).

(NADEEM AHMAD)
CONTENTS

Chapter No. Description Page No.
List of Tables i
List of Figures Vi
List of Appendices Viii
Abstract Xi
1 INTRODUCTION 1
2 REVIEW OF LITERATURE 6
2.1 Drought and food security 6
2.2 Morpho-physiological responses of drought 6
2.2.1 Crop growth and establishment 7
2.2.2 Fertilization and seed setting 8
2.2.3 Grain filling and development 9
2.2.4 Yield and yield components 10
2.3 Seed quality 12
2.4 Selection criterion 12
2.4.1 Morphological criterion 13
2.4.2 Physiological criterion 13
2.5 Gene action 15
2.6 Heritability 17
2.7 Correlation 19
3 MATERIALS AND METHODS 22
3.1 Growing conditions 22
3.2 Plant material 22
3.3 Assessment of genetic variability for drought tolerance 22
3.4 Development of genetic material 23
3.5 Evaluation of genetic material 24
3.5.1 Evaluation in the green-house 25
3.5.2 Evaluation in the field 25
3.6 Biometrical analysis 28
3.6.1 Statistical analysis of variance 28
3.6.2 Diallel analysis 28
3.6.3 Means comparison and estimation of components of variation 33
3.6.4 Correlation analysis 34
4 RESULTS AND DISCUSSION 35
4.1 Screening and selection of parents 35
4.2 Mean performance of parents and crosses for seedling traits 37
4.3 Mean performance of parents and crosses for whole plant traits 40
4.4 Assessment of variability 47
4.4.1 Analysis of variance 47
4.4.2 Adequacy of additive-dominance model 47
4.5 Genetic analysis 52
CONTENTS

Chapter No. Description Page No.
4.5.1 Root length under normal and drought 52
4.5.2 Shoot length under normal and drought 55
4.5.3 Root weight under normal and drought 59
4.5.4 Shoot weight under normal and drought 64
4.5.5 Days to heading under normal and drought 67
4.5.6 Days to maturity under normal and drought 73
4.5.7 Plant height under normal and drought 77
4.5.8 Flag leaf area under normal and drought 81
4.5.9 Tillers per plant under normal and drought 85
4.5.10 Spike length under normal and drought 89
4.5.11 Spikelets per spike under normal and drought 93
4.5.12 Spike weight under normal and drought 97
4.5.13 Grains per spike under normal and drought 99
4.5.14 Spike grain weight/spike straw weight ratio under normal 103
and drought
4.5.15 Thousand-kernel weight under normal and drought 107
4.5.16 Biomass per plant under normal and drought 113
4.5.17 Harvest index under normal and drought 117
4.5.18 Rate of photosynthesis under normal and drought 121
4.5.19 Rate of transpiration under normal and drought 125
4.5.20 Grain yield per plant under normal and drought 127
4.6 Correlation analysis 133
4.6.1 Correlation coefficients among seedling traits 133
4.6.2 Correlation coefficients among whole plant traits 133
5 SUMMARY 146
6 LITERATURE CITED 149
7 APPENDICES 174-188
LIST OF TABLES

Table No. Description Page No.
2.1 Yield losses at various growth stages under drought in wheat 11
2.2 Various traits used as selection criteria under drought stress in wheat 12
3.1 Parents selected for crossing 23
3.2 Crossing plan of the selected parents 24
3.3 Morpho – physiological traits studied under normal and drought conditions 25
4.1 Mean squares and genetic components for seedling traits under normal and 36
drought conditions.
4.2 Best and worst performing accessions on the basis of relative values 37
4.3 Parentage and relative values of selected parents 37
4.4 Mean squares of various seedling traits in 7×7 diallel cross under normal and 48
drought conditions of Triticum aestivum L.
4.5 Mean squares of various plant traits in 7×7 diallel cross under normal condition 49
of Triticum aestivum L.
4.6 Mean squares of various plant traits in 7×7 diallel cross under drought condition 50
of Triticum aestivum L.
4.7 Scaling tests for adequacy of additive-dominance model for various plant traits 51
under normal condition of Triticum aestivum L.
4.8 Scaling tests for adequacy of additive-dominance model for various plant traits 52
under drought condition of Triticum aestivum L.
4.9 Analysis of variance of root length under normal and drought conditions in 7×7 53
diallel cross of Triticum aestivum L.
4.10 Mean squares of components of variation of root length under normal condition in 54
7×7 diallel cross of Triticum aestivum L.
4.11 Mean squares of components of variation of root length under drought condition 54
in 7×7 diallel cross of Triticum aestivum L.
4.12 Estimates of components of variation of root length under normal and drought 55
conditions in 7×7 diallel cross of Triticum aestivum L.
4.13 Analysis of variance of shoot length under normal and drought conditions in 7×7 57
diallel cross of Triticum aestivum L.
4.14 Mean squares of components of variation of shoot length under normal condition 58
in 7×7 diallel cross of Triticum aestivum L.
4.15 Mean squares of components of variation of shoot length under drought condition 58
in 7×7 diallel cross of Triticum aestivum L.
4.16 Estimates of components of variation of shoot length under normal and drought 59
conditions in 7×7 diallel cross of Triticum aestivum L.
4.17 Analysis of variance of root weight under normal and drought conditions in 7×7 61
diallel cross of Triticum aestivum L.
i
LIST OF TABLES

Table No. Description Page No.
4.18 Mean squares of components of variation of root weight under normal condition 62
in 7×7 diallel cross of Triticum aestivum L.
4.19 Mean squares of components of variation of root weight under drought condition 62
in 7×7 diallel cross of Triticum aestivum L.
4.20 Estimates of components of variation of root weight under normal and drought 63
conditions in 7×7 diallel cross of Triticum aestivum L.
4.21 Analysis of variance of shoot weight under normal and drought conditions in 7×7 65
diallel cross of Triticum aestivum L.
4.22 Mean squares of components of variation of shoot weight under normal condition 66
in 7×7 diallel cross of Triticum aestivum L.
4.23 Mean squares of components of variation of shoot weight under drought condition 66
in 7×7 diallel cross of Triticum aestivum L.
4.24 Estimates of components of variation of shoot weight under normal and drought 67
conditions in 7×7 diallel cross of Triticum aestivum L.
4.25 Analysis of variance of days to heading under normal and drought conditions in 69
7×7 diallel cross of Triticum aestivum L.
4.26 Mean squares of components of variation of days to heading under normal 70
condition in 7×7 diallel cross of Triticum aestivum L.
4.27 Mean squares of components of variation of days to heading under drought 70
condition in 7×7 diallel cross of Triticum aestivum L.
4.28 Estimates of components of variation for days to heading under normal and 71
drought conditions in 7×7 diallel cross of Triticum aestivum L.
4.29 Analysis of variance of days to maturity under normal and drought conditions in 73
7×7 diallel cross of Triticum aestivum L.
4.30 Mean squares of components of variation of days to maturity under normal 74
condition in 7×7 diallel cross of Triticum aestivum L.
4.31 Mean squares of components of variation of days to maturity under drought 74
condition in 7×7 diallel cross of Triticum aestivum L.
4.32 Estimates of components of variation for days to maturity under normal and drought 75
conditions in 7×7 diallel cross of Triticum aestivum L.
4.33 Analysis of variance of plant height under normal and drought conditions in 77
7×7 diallel cross of Triticum aestivum L.
4.34 Mean squares of components of variation of plant height under normal 78
condition in 7×7 diallel cross of Triticum aestivum L.
4.35 Mean squares of components of variation of plant height under drought 78
condition in 7×7 diallel cross of Triticum aestivum L.
4.36 Estimates of components of variation for plant height under drought and drought 79
conditions of in 7×7 diallel cross of Triticum aestivum L.
ii
LIST OF TABLES

Table No. Description Page No.
4.37 Analysis of variance of flag leaf area under normal and drought conditions in 81
7×7 diallel cross of Triticum aestivum L.
4.38 Mean squares of components of variation of flag leaf area under normal 82
condition in 7×7 diallel cross of Triticum aestivum L.
4.39 Mean squares of components of variation of flag leaf area under drought 82
condition in 7×7 diallel crosses of Triticum aestivum L.
4.40 Estimates of components of variation for flag leaf area under normal and drought 83
conditions in 7×7 diallel cross of Triticum aestivum L.
4.41 Analysis of variance of tillers per plant under normal and drought conditions in 85
7×7 diallel cross of Triticum aestivum L.
4.42 Mean squares of components of variation of tillers per plant under normal 86
condition in 7×7 diallel cross of Triticum aestivum L.
4.43 Mean squares of components of variation of tillers per plant under drought 86
condition in a 7×7 diallel cross of Triticum aestivum L.
4.44 Estimates of components of variation for tillers per plant under normal and drought 87
conditions in a 7×7 diallel cross of Triticum aestivum L.
4.45 Analysis of variance of spike length under normal and drought conditions in 89
7×7 diallel cross of Triticum aestivum L.
4.46 Mean squares of components of variation of spike length under normal condition 90
in 7×7 diallel cross of Triticum aestivum L.
4.47 Mean squares of components of variation of spike length under drought 90
condition in 7×7 diallel cross of Triticum aestivum L.
4.48 Estimates of components of variation for spike length under normal and drought 91
conditions in 7×7 diallel cross of Triticum aestivum L.
4.49 Analysis of variance of spikelets per spike under normal and drought conditions 93
in 7×7 diallel cross of Triticum aestivum L
4.50 Mean squares of components of variation of spikelets per spike under normal 94
condition in 7×7 diallel cross of Triticum aestivum L.
4.51 Mean squares of components of variation of spikelets per spike under drought 94
condition in 7×7 diallel cross of Triticum aestivum L.
4.52 Estimates of components of variation for spikelets per spike under normal and 95
drought conditions in 7×7 diallel cross of Triticum aestivum L.
4.53 Analysis of variance of spike weight under normal conditions in 7×7 diallel 97
cross of Triticum aestivum L.
4.54 Mean squares of components of variation of spike weight under normal 98
condition in 7×7 diallel cross of Triticum aestivum L.
iii