Posted on Dec 01, 2010
Sorghum (Sorghum bicolor L. Moench) is an important cereal crop for feed, food, and a biofuel uses. It is as input efficient, drought tolerant, and environmentally friendly crop. Nitrogen (N) and water availability are considered two of the major limiting factors in crop growth. Nitrogen fertilization accounts for about 40% of the total production cost in sorghum. In cereals, including sorghum, the nitrogen use efficiency (NUE) from fertilizer is approximately 33% of the amount applied. There is therefore extensive concern in relation to the N that is not used by the plant, which is lost by leaching of nitrate, denitrification from the soil, and loss of ammonia to the atmosphere, all of which can have deleterious environmental effects. To improve the potential of sorghum as a leading and cost effective bioenergy crop, the enhancement of NUE must be addressed. To this end, we have identified a sorghum line (SanChi San) that displays about 25% increase in NUE over other sorghum lines. As such, the overarching goal of this project is to employ complementary strategies to enhance the ability of grain sorghum to become an efficient nitrogen user. To achieve the project goal, we will pursue the following specific objectives:
Objective 1: Conduct quantitative trait loci (QTL) analysis and marker identification for nitrogen use efficiency (NUE) in a grain sorghum RIL population
Objective 2: Identify novel candidate genes for NUE using proteomic and gene expression profiling comparisons of high- and low- NUE RILs. Candidate genes will eventually be used for transgenic manipulation of NUE in grain and sweet sorghum.
This project will employ proteomics and gene expression profiling strategies to identify genes controlling NUE, one of the most complex and economically important traits in cereal crops. At the completion of the proposed work, we will have: 1) identified novel alleles in wild sorghum germplasm that are useful to improve both cultivated grain and sweet sorghum; 2) selected individual plants that exhibit high NUE within a breeding population on the basis of these markers