| dc.contributor.author | Adewale, S.A. |
| dc.date.accessioned | 2022-11-30T12:42:27Z |
| dc.date.available | 2022-11-30T12:42:27Z |
| dc.date.issued | 2021 |
| dc.identifier.citation | Adewale, S.A. (2021). Inheritance patterns and genome-wide association study of tropical early-maturing maize inbred lines under Striga infestation and drought stress environments. Ile-Ife, Nigeria: Obafemi Awolowo University (218 p.). |
| dc.identifier.uri | https://hdl.handle.net/20.500.12478/7943 |
| dc.description.abstract | This study determined the gene action controlling grain yield and other agronomic traits among newly-developed early-maturing maize inbred lines under drought stress, Striga infestation, optimal conditions and across research environments; examined the combining ability of the early maize inbred lines under each and across research environments; classified the inbred lines into heterotic groups using DArTseq (Diversity Arrays Technology sequencing) markers and combining ability effects methods and determined genome-wide marker-trait association of key Striga resistance agronomic traits using representative DArTseq markers. These were with a view to facilitating efficient maize hybrid development programme for stress and non-stress environments in sub-Saharan Africa. The research was carried out in two phases which included: (1) generation and evaluation of testcrosses, and (2) genome-wide association study. In the first phase, five inbred testers were crossed to thirty-eight inbreds using line x tester mating design. A total of 190 testcross hybrids plus ten hybrid checks (the hybrid trial) were evaluated under artificial Striga infestation, drought stress and optimal environments from 2017 to 2019. In the second phase, 132 inbred lines including one check (the inbred trial) were evaluated under artificial Striga infestation and optimal conditions from 2017 to 2019. The 132 inbred lines were genotyped using DArTseq markers for the molecular analysis. Data collected on grain yield and other measured traits were subjected to Analysis of Variance (ANOVA). The testcrosses were further subjected to line x tester analysis. Results revealed preponderance of GCA over SCA sum of squares for grain yield and most other assayed traits under Striga-infested, optimal and across research conditions whereas under drought stress conditions, there was predominance of SCA effects over GCA effects for grain yield and most other traits. Inbred lines TZEI 1203 and TZEI 1348 were identified as having highest GCA effects across all research conditions. The inbreds were classified into two, three and four heterotic groups each by the DArTseq-SNP molecular marker-based GD, HGCAMT and HSGCA methods, respectively. The DArTseq grouping method was the most efficient in classifying the inbreds into heterotic groups, followed by the HGCAMT method and then HSGCA method. The 132 inbred lines were classified into two major clusters by both the population structure and neighbour joining phylogenetic analyses. Twenty-four markers located on several maize chromosomes were found to be significantly associated with Striga adaptive traits under Striga infestation. Three putative genes GRMZM2G060216, GRMZM2G057243 and GRMZM2G164743 associated with plant defense mechanism under Striga infestation were detected on chromosomes 3, 9 and 10, respectively. The study concluded that additive gene effects were predominant in controlling the inheritance of grain yield and other traits under Striga-infestation while under drought stress, non-additive gene effects were more important. |
| dc.format.extent | 218 p. |
| dc.language.iso | en |
| dc.publisher | Obafemi Awolowo University |
| dc.subject | Maize |
| dc.subject | Striga Hermonthica |
| dc.subject | Early Maturity |
| dc.subject | Varieties |
| dc.subject | Genomes |
| dc.title | Inheritance patterns and genome-wide association study of tropical early-maturing maize inbred lines under striga infestation and drought stress environments |
| dc.type | Thesis |
| cg.contributor.crp | Maize |
| cg.contributor.affiliation | Obafemi Awolowo University |
| cg.coverage.region | Africa |
| cg.coverage.region | West Africa |
| cg.coverage.country | Nigeria |
| cg.coverage.hub | Headquarters and Western Africa Hub |
| cg.researchtheme | Biotech and Plant Breeding |
| cg.identifier.bibtexciteid | ADEWALE:2021 |
| cg.authorship.types | CGIAR and developing country institute |
| cg.iitasubject | Agronomy |
| cg.iitasubject | Food Security |
| cg.iitasubject | Maize |
| cg.iitasubject | Plant Breeding |
| cg.iitasubject | Plant Diseases |
| cg.iitasubject | Plant Health |
| cg.iitasubject | Plant Production |
| cg.notes | IITA supervisor: Dr. Badu-Apraku, B. |
| cg.publicationplace | Ile-Ife, Nigeria |
| cg.accessibilitystatus | Limited Access |
| cg.reviewstatus | Internal Review |
| cg.usagerightslicense | Copyrighted; all rights reserved |
| cg.targetaudience | Scientists |
| cg.futureupdate.required | No |
| cg.contributor.acknowledgements | My utmost gratitude goes to the Almighty God for sustaining me through the period of the PhD program. Also, my sincere appreciation goes to my supervisors, Dr. R. O. Akinwale and Dr. B. Badu-Apraku for their invaluable contributions, support and guidance in the course of this work. In addition, I am grateful to the International Institute of Tropical Agriculture (IITA) for granting me the Graduate Research Fellowship under the Stress Tolerant Maize for Africa (STMA) Project to enable me conduct research activities for my PhD thesis.
I also express my appreciation to Drs. A. Oluwaranti, A. S. Oladejo, Q. O. Oloyede-Kamiyo, B. O. Odu, Prof. A. A. Amusan, Prof. M. A. B. Fakorede and the Crop Production and Protection Head of Department, Prof. M. B. Sosan for their impact during the course of this research. I will not forget to express my sincere thanks and appreciation to the staff of the IITA Maize Improvement Program especially Dr. A. O. Talabi for their support and contributions to the success of my research. My sincere thanks to the Integrated Genotyping Service and Support (IGSS) platform of BecA-ILRI, Kenya for providing the genotyping grant for the molecular aspect of the research and Dr. A. A. Paterne and Dr. A. L. Garcia-Oliveira of IITA-Ibadan for assisting with genotypic data curation and analysis. Also, my colleagues Drs. S. A. Oyekale, E. Obeng-Bio, N. Tchala, A. Oyetunde, C. Nelimor and Mr. O. Obisesan, interacting with you guys was worthwhile.
My indebtedness goes to my wonderful parents, Mr. M. A. and Mrs. E. O. Adewale for their financial support, guidance, encouragement and prayers. I express my heartfelt gratitude to my siblings for their prayers and love. Finally, I so much appreciate my dear wife, Mrs. Blessing Adewale for the immense support during the course of this work. |
