– Genetic Analysis of Progenies from Diallel Crosses Among Eight Varieties of Different Maturity Groups of Maize –
Download Genetic Analysis of Progenies from Diallel Crosses Among Eight Varieties of Different Maturity Groups of Maize project materials: This project material is ready for students who are in need of it to aid their research.
ABSTRACT
A full-diallel cross comprising eight varieties belonging to four different maturity groups was developed and studied for fifteen characters to determine general and specific combining ability (GCA, SCA), nature of gene action of parents and hybrids, and heterosis.
Eighty-one genotypes comprising the crosses, reciprocals, selves, parents and nine checks were evaluated at Kadawa under irrigation in two different environments (sowing dates).
Analysis of variance revealed significant differences for GCA and SCA, indicating the presence of additive as well as non-additive gene action. In both environments, the GCA mean squares were highly significant and higher than the SCA mean squares for all traits except cob diameter at environment one and four traits at environment two.
The study revealed significant GCA x environment interaction indicating different parental varieties behaved differently under different environments, hence there is a need to select different parental varieties for hybrid production for a specific environment.
TABLE OF CONTENTS
Title page …………………………………………………………………………… ii
Declaration …………………………………………………………………………. iii
Certification ………………………………………………………………………… iv
Dedication ………………………………………………………………………….. v
Acknowledgements ………………………………………………………………… vi
Abstract …………………………………………………………………………….. viii
Table of Contents …………………………………………………………………… ix
List of Tables ……………………………………………………………………….. xii
Abbreviations ………………………………………………………………………. xiv
CHAPTER ONE: INTRODUCTION
1.1 Introduction …………………………………………………………………… 1
1.2 Justification………………………………………………………………………………………….. 3
1.3 Objectives……………………………………………………………………………………………. 4
CHAPTER TWO: LITERATURE REVIEW
2.1 Diallel Mating Design ……………………………………………………….. 5
2.2 Combining Ability …………………………………………………………… 7
2.3 Heterosis and Inbreeding Depression ….…………………………………….. 8
2.4 Genotype by Environment Interaction (GE) ………………………………… 9
2.4.1 Types of Environments ………………………………………………………. 10
CHAPTER THREE: MATERIALS AND METHODS
3.1 Origin and Description of the Varieties …………………………………….. 13
3.2 Crossing Nursery …………………………………………………………….. 14
3.3 Field Evaluation …………………………………………………………….. 15
3.3.1 Description of Experimental Site …………………………………………… 20
3.3.2 Experimental Design ………………………………………………………………. 20
3.3.3 Data Collection and Observations ………………………………………….. 21
3.4 Data Analysis ……………………………………………………………….. 23
3.5.0 Genetic Analysis ……………………………………………………………. 26
3.5.1 Combining Ability Estimation ……………….……………………………… 26
3.6 Heterosis Estimation …………………………………………………………32
3.7 Inbreeding depression………………………………………………………………………… 33
CHAPTER FOUR: RESULTS
4.1 Analysis of Variance ……………………………………………………………………… 34
4.2 Mean Performance …………………………………………………………… 38
4.3.0 Genetic Analysis ……………………………………………………………… 64
4.3.1 ANOVA for Combining Ability ……………………………………………… 64
4.3.2 Estimates of General and Specific Combining Ability Variances…………… 70
4.3.3 Estimates of Combining Ability Effects …………………………………….. 75
4.3.4 Estimates of Heterosis and Inbreeding Depression………………………….. 86
CHAPTER FIVE: DISCUSSION 93
CHAPTER SIX: SUMMARY, CONCLUSION AND RECOMMENDATIONS
6.1 Summary………………………………………………………………………. 105
6.2 Conclusion ……………………………………………………………………. 108
6.3 Recommendations ……………………………………………………………. 108
REFERENCES ……………………………………………………………………. 110
INTRODUCTION
Zea is a genus belonging to the grass family, Poaceae in the Andropogoneae tribe but is commonly cited in the literature to belong to the tribe Maydeae (Mangelsdorf, 1974). Zea was derived from an old Greek name for a food grass.
The genus Zea consists of four species of which only Zea mays spp. is economically important (Mangelsdorf, 1974). The number of chromosomes in Zea mays is 2n = 20, 21, 22, 24 (FAO, 2000a).
The centre of origin for Zea mays spp. mays have been established as the Mesoamerican region, now Mexico and Central America (Mangelsdorf, 1974). Archaeological records suggest that domestication of maize began at least 6,000 years ago occurring independently in regions of the South-western United States, Mexico, and Central America (Mangelsdorf, 1974).
Under natural conditions, maize reproduces only by seed production. Pollination occurs with the transfer of pollen from the tassel to the silks of the ear. About 95% of the ovules are cross-pollinated and the rest are self-pollinated (Poehlman, 1959).
REFERENCES
Acquaah, G. (2007). Principles of plant genetics and breeding. Blackwell publishing city. pp. 339.
Ado, S.G., Valencia, J.A., Falaki, A.M. and Miko, S. (1999). Sustainable Maize Production in Nigeria: The challenges in the coming Millennium. Proc. Of National Maize Workshop. pp.124-128.
Ado, S.G., Usman, I.S. and Abdullahi, U.S. (2007). Recent development in maize research at Institute for Agricultural Research Samaru, Nigeria. African Crop Science Conference Proceedings, 8: 1871-1874.
Allard, R.W. and Bradshaw, A.D. (1964). Implications of genotype-environment interactions in applied plant breeding. Crop Sci., 4: 503-508.
Anonymous. (1987). Maize Production Guide. Extension Bull. No. 11. National Agricultural Extension and Research Liaison Services (NAERLS), A.B.U. Zaria pp .10.
Badu-Apraku, B. and Fakorede, M. A. B. (1999). Impact, challenges and prospect of maize research and development in West and Central Africa. Progress in breeding for Striga hermonthica resistant early and extra-early maize varieties. Proceedings of a Regional Maize Workshop, 4-7 May, 1999, IITA–Cotonou, Benin Republic WECAMAN/IITA Pp. 147-162.
StudentsandScholarship Team.
Be the first to comment