Harvey, Lorin Michael (2016-04). QTL Analysis of Yield Components in Cotton. Master's Thesis.
Cotton is the world's leading natural textile fiber and oilseed crop, with a global economic impact of over $600 billion. However, few QTLs have been identified and linked with yield traits. In this study, a large number of SNP markers were mapped across all 26 cotton chromosomes using an inter-specific RIL population. It is also one of the first genetic maps created using markers obtained by ddRADseq. A total of 18 QTLs controlling lint percent and seed index were identified. The phenotypic effect of each of the QTLs ranges from 6.15 to 37.48%. However, only one of the QTLs was discovered in multiple environments. This suggests that the QTLs, and subsequently the genes controlling yield traits are highly affected by GxE interactions and gene-gene interactions. The goal of being able to apply MAS to wide spread geographical areas in an attempt to improve the efficiency of cotton breeding might not be practical. MAS may be better suited for small targeted areas, where environments are more similar.