Wednesday, 16 April 2014

Trait analysis and association mapping to identify QTLs associated with agronomic and yield component traits in elite irrigated rice breeding lines

 A PBGB Division Seminar

By Hasina Begum
PhD Research Scholar

2:00 p.m., Wednesday, 23 April 2014
Umali Room C, IRRI


Trait characterization of 431 elite rice breeding lines using 19 agronomic traits was done in the field for two seasons using a randomized complete block design. This research aims to determine the extent of trait variation between breeding lines and the relationship between yield and other traits to identify those that could serve as predictors for improving rice yield for breeding. Correlation and broad-sense heritability characteristics associated with grain yield showed significant genetic variation (P < 0.001) between genotypes. Regression analysis revealed that yield was significantly associated with yield-related traits. Significant interactions between seasons indicated that breeders should consider season-specific traits. The whole panel was genotyped using genotyping by sequencing at Cornell University. After SNP analysis, 64,903 SNPs were used for association mapping. This study describes the detection of QTLs for agronomic and yield traits through association mapping. Several of the associations involved SNPs that are tightly linked to known major genes determining morpho-agronomic traits in rice. Most of the QTLs identified are season-specific. Some other novel QTL alleles that are also identified in this study could provide alternative sources of QTLs for increasing yield potential in rice. We investigated candidate genes for flowering times because large-effect QTLs were detected for this trait, and because considerable information is known about the actual genes and physiological mechanisms of this pathway. These potential QTLs for selected traits are of interest to breeders and need to be further validated. Moreover, the findings of this study will facilitate the development of SNP markers for marker-assisted breeding.

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