EVALUATION OF GRASS ECOTYPES FOR POTENTIAL USE IN RESEEDING OF PASTORAL FIELDS IN THE ARID AND SEMI-ARID LANDS OF KENYA By Everlyne CheptArus KirwA, B.SC., M.Sc. (UoN) A80/83321/2012 A THESIS SUBMITTED IN FULFILMENT OF REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN GENETICS AND PLANT BREEDING DEPARTMENT OF PLANT SCIENCE AND CROP PROTECTION FACULTY OF AGRICULTURE UNIVERSITY OF NAIROBI ©2019 DEDICATION This thesis is dedicated to my lovely husband Dr. Muge and children Peter, Chantal and Leon for their relentless support and encouragement during the preparation. ii ACKNOWLEDGEMENT I acknowledge the funding support from the East African Agricultural productivity programme (EAAPP) for the scholarship and, Arid and Semi-Arid Lands Agricultural productivity research programme (ASAL-APRP) and National Council for Science and Technology for partially supporting my research work. I sincerely appreciate the input of my supervisors Prof. Eliud Kahiu Ngugi, Prof. George N. Chemining’wa and Dr. William Ngoyawu Mnene who greatly supported me in the development of this thesis. I would also like to sincerely appreciate posthumously the input of the late Prof. Kiarie Njoroge who guided me through proposal development, research implementation and partly writing of my thesis. Thanks are also due to the Director General, Kenya Agricultural and Livestock Research Organization and the staff of KALRO Headquarters, Kiboko, Buchuma, Mtwapa and Biotechnology Centre Kabete for logistical support. Finally to my family, relatives and friends, thanks all for the patience and your prayers. May God almighty bless you all. iii ACRONYMS AEZ Agro-ecological Zone AMMI Additive Main and Multiplicative Interaction ANOVA Analysis of variance ASALs Arid and Semi-Arid Lands CBFSB Community Based Range Forage Seed Bulking FAO Food and Agriculture Organization ICPALD IGAD Centre for Pastoral Areas and Livestock Development ILRI International Livestock Research Institute KALRO Kenya Agricultural and Livestock Research Organization KBK Kiboko KLF Kilifi MGD Magadi PVS Participatory Variety Selection SRAP Sequence Related Amplified Polymorphism TVT Taita Taveta USDA United States Department of Agriculture iv TABLE OF CONTENTS DECLARATION ......................................................................................................................... i DEDICATION............................................................................................................................ii ACKNOWLEDGEMENT ........................................................................................................ iii ACRONYMS ............................................................................................................................ iv LIST OF TABLES ..................................................................................................................... ix LIST OF FIGURES .................................................................................................................xiii LIST OF PLATES .................................................................................................................... xv ABSTRACT ............................................................................................................................ xvi CHAPTER ONE ......................................................................................................................... 1 GENERAL INTRODUCTION ................................................................................................... 1 1.1 Importance of ASALs in livestock production ................................................................. 1 1.2 Problem Statement .......................................................................................................... 2 1.3 Justification of the study .................................................................................................. 4 1.4 Main Objective ................................................................................................................ 8 1.4.1. Specific Objectives .................................................................................................. 8 1.4.2. Hypotheses............................................................................................................... 8 CHAPTER TWO ........................................................................................................................ 9 LITERATURE REVIEW ............................................................................................................ 9 2.1. Importance of grass forage in livestock production .......................................................... 9 2.2. Description of Eragrostis superba Peyr ........................................................................... 9 2.3. Description of Cenchrus ciliaris L. ................................................................................ 12 2.4. Morphological characterization of forage grass.............................................................. 15 2.4.1 Principal component analysis ................................................................................. 16 2.4.2 Cluster analysis ...................................................................................................... 17 2.5. Nutritional value of grasses ........................................................................................... 18 2.6. Seasonal variation in grass forage availability................................................................ 19 2.7. Participatory selection of varieties ................................................................................. 20 2.8. Molecular characterization of grasses ............................................................................ 21 2.9. Agro-ecological zones ................................................................................................... 26 v CHAPTER THREE .................................................................................................................. 29 CHARACTERIZATION OF ECOTYPES OF CENCHRUS CILIARIS L. AND ERAGROSTIS SUPERBA PEYR USING MORPHOLOGICAL AND NUTRITIVE VALUE TRAITS ............ 29 3.1. Abstract ......................................................................................................................... 29 3.2. Introduction ................................................................................................................... 30 3.3. Materials and Methods .................................................................................................. 33 3.3.1. Collection sites ....................................................................................................... 33 3.3.2. Study sites .............................................................................................................. 36 3.3.3. Field conditions and layout .................................................................................... 37 3.3.4. Data collection ....................................................................................................... 38 3.3.4. Data analysis .......................................................................................................... 42 3.4. Results .......................................................................................................................... 43 3.4.1. Germination capacity of Cenchrus ciliaris.............................................................. 43 3.4.2. Phenotypic characterization of Cenchrus ciliaris ecotypes ..................................... 45 3.4.3. Variation in flowering phenology of Cenchrus ciliaris between cuts ...................... 51 3.4.4. Variation in flowering phenology between sites of collections of Cenchrus ciliaris 52 3.4.5. Variation in flowering phenology between ecotypes of Cenchrus ciliaris ............... 53 3.4.6. Correlation analysis between traits for Cenchrus ciliaris ........................................ 55 3.4.7. Analysis of nutritive value components among sites of origin for Cenchrus ciliaris ecotypes ................................................................................................................. 57 3.4.8. Comparison of nutritive value components among ecotypes of Cenchrus ciliaris ... 57 3.4.9. Phenotypic characterization of Eragrostis superba ecotypes................................... 59 3.4.10. Correlation analysis between traits for Eragrostis superba ..................................... 63 3.4.11. Analysis of nutritive value components between sites of origin for Eragrostis superba ecotypes ................................................................................................................. 65 3.4.12. Comparison of nutritive value components among Eragrostis superba ecotypes .... 65 3.5. Discussion ..................................................................................................................... 67 3.6. Conclusion .................................................................................................................... 79 CHAPTER FOUR .................................................................................................................... 80 vi CHARACTERIZATION OF ECOTYPES OF CENCHRUS CILIARIS L. AND ERAGROSTIS SUPERBA PEYR. USING SEQUENCE RELATED AMPLIFIED POLYMORPHISM (SRAP) ................................................................................................................................................. 80 4.1 Abstract ........................................................................................................................