ABSTRACT

This study investigated the mutagenic effect of x-ray on growth of pepper (Capsicum annum) of three different varieties of pepper- Langa langa, (World bitter and California wonder). The experiment was carried out in the screen house of Michael Okpara University of Agriculture, Umudike, Umuahia, Abia State, Nigeria, and in the research field of National Plant, Soil and Water Laboratory, Umudike. The experiment was carried out using seeds collected from National Agricultural Seed Council (NASC), Umudike. The experiment was laid out as Randomised Complete Block Design (RCBD) replicated three times. Parameters evaluated include root length, shoot height, number of leaves, germination percentage, leaf area and plant girth. The x-ray irradiation doses used were 1 Mgy, 2 Mgy, 4 Mgy, 6 Mgy and 8 Mgy. From the result, it was observed that World bitter produced its highest germination percentage (59%), highest number of leaves (3.4 mean value), highest plant girth (1.9 mm) and highest root length (2.4 mm) all at 6 Mgy x-ray radiation dose while Langa langa produced the highest number of leaves at 1 Mgy (3.4 mean value) and 4 Mgy x-ray radiation dose (at 2.7 mean value). Valencia sweet pepper produced the least percentage germination, least number of leaves and least root length. This evaluation suggests that the breeders could use these observations in their breeding selection.

TABLE OF CONTENTS

Title page                                                                                                        i

Declaration ii

Certification iii

Dedication iv

Acknowledgements v

Table of Contents vi

List of Tables viii 

List of Figures ix

List of Plates x

Abstract xi

CHAPTER ONE: INTRODUCTION

1.1 Background of the Study 1

1.2 Justification of the Study 4

1.3 Aim of the Study 4

1.4      Objectives of the Study 4

CHAPTER TWO: LITERATURE REVIEW

2.1 Mutation 5

2.1.1 Types of Mutation 5

2.1.2 Induced Mutation 6

2.1.3 Physical Mutagens 6

2.2 X-rays 7

2.3 Radiation Units 8

2.4 Chemical Mutagens 8

2.4.1 Spontaneous Mutation 9

2.4.2 Mutation Rate 9

2.4.3 Effect of Mutation on the Phenotype 10

2.4.4 How Does a Mutation Act? 11

2.4.5 Significance of Mutation 11

2.4.5.1 Application in Plant Breeding 11

2.4.5.2 Mutation Breeding of Pepper 12

2.4.5.3 Uses of Pepper 13

2.4.5.4 Medicinal Uses of Pepper 13

2.4.5.5 Role in Evolution 14

CHAPTER THREE: MATERIALS AND METHODS

3.1 Study Area 15

3.2 Design of the Experiment 15

3.3 Collection of Samples 15

3.4 Seed Treatment 16

3.5 Dosimetry 16

3.6 Treatment 16

3.7 Measurement Parameters                                              16

3.7.1 Germination Percentage                                            17

3.7.2 Plant Height                                                                      17

3.7.3 Root Length                                                              17                              

3.8 Statistical Analysis 17

CHAPTER FOUR: RESULTS             18

CHAPTER FIVE

5.1 Discussion 29

5.2 Discussion 30

References 31