Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.

Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.

Mapping and validation of QTLs for nitrogen use efficiency traits in sorghum and identification of candidate genes associated with QTLs

Malleswari Gelli, University of Nebraska - Lincoln

Abstract

Understanding the genetic variation of sorghum response to limited nitrogen supply is important for elucidating the underlying genetic mechanisms of nitrogen use efficiency (NUE). In this study, two F7 recombinant inbred line populations were developed and used to detect QTLs for multiple agronomic traits. The populations were analyzed under normal N (100 kg.ha-1 fertilizer) and low N (0 kg.ha-1 fertilizer) conditions for two years with two replications each. The linkage maps, spanning a length of 1584 cM and 1527 cM were developed using single nucleotide polymorphisms (SNPs) generated from genotyping-by-sequencing (GBS) technology. Composite interval mapping analysis detected several QTLs for 11 traits tested across two populations. The phenotypic variation explained by individual QTL ranged from 6.2% to 50.8%. Five QTLs were detected consistently across two populations. Co-localized regions affecting multiple traits were detected on chromosomes 1, 3, 6, 7 and 9. These pleiotropic regions were coincident with the genomic regions of cloned QTLs, including Ma3 for flowering time on chromosome 1 and Dw2 for plant height on chromosome 6. In the co-localized regions, Illumina RNA sequencing detected differentially expressed genes related to nitrogen metabolism, glycolysis, seed storage proteins, genes involved in plant hormone metabolism and several membrane transporters. Genes underlying the QTL regions could be potential targets for improving the sorghum performance under limited N fertilizer through marker assisted selection.^

Subject Area

Agriculture, Agronomy|Biology, Molecular|Agriculture, Plant Culture

Recommended Citation

Gelli, Malleswari, "Mapping and validation of QTLs for nitrogen use efficiency traits in sorghum and identification of candidate genes associated with QTLs" (2013). ETD collection for University of Nebraska - Lincoln. AAI3602788.
http://digitalcommons.unl.edu/dissertations/AAI3602788

Share

COinS