Stress-Tolerant Crop Development for Nevada


sorghum

Grain sorghum is the fifth most important grain crop in the world in terms of total production. It is a biofuel, animal feed and gluten-free “ancient grain” in the U.S. and a key subsistence crop throughout sub-Saharan African and India. Drought, heat, and soil salinity are major stresses that limit crop production either by directly inhibiting plant growth or by reducing pollen fertility and therefore seed set and grain yield.

The Sorghum Association Panel (SAP) consists of over 300 cultivars of sorghum having a wide range of genetic codes and environmental variation. It has been widely used to identify the chromosomal regions associated with traits of interest to plant breeders, including grain yield and quality. This project is locating field sites in Northern and Southern Nevada know to be salty, grow the SAP, and study whole-plant, root, and pollen responses to heat, drought, and saline stress. Researchers will be using a genome-wide association study (GWAS) to identify genes associated with stress tolerance. Molecular markers for stress-tolerance genes will be developed in subsequent studies to assist in breeding stress-tolerant sorghum cultivars that grow well in Nevada environments.

Abiotic stresses negatively impact crop production all over the world. About 20% of the 230 million ha under irrigation world-wide is estimated to suffer from some salinization-affected losses in productivity and saline soils make up approximately 50% of the irrigated land area in Nevada. This makes Nevada an ideal place for studying co-occurring desiccation stresses (heat, drought, and salinity) because rainfall is minimal, making precise control over water applications possible through deficit irrigation. Thus, genomic tools for crop improvement, such as genome-wide association studies (GWAS) that are well-established in more traditionally agricultural regions may be tested effectively in Nevada for their ability to quickly and efficiently adapt new crops to new environments within specified stress thresholds.