2012 Annual Report
1a.Objectives (from AD-416):
The primary objective of this proposal is to identify genes related to tolerance to phosphorous (P) deficiency in sorghum, with a focus on homologs of the rice phosphorous uptake efficiency gene, Pup1, in sorghum. Once sorghum P efficiency genes are identified, this information and new knowledge will be transferred to the Sorghum Molecular Breeding (SorghumMB) project for deployment into breeding programs. This project is based on the work of an interdisciplinary research team from Embrapa (Brazil), USDA-ARS at Cornell University in Ithaca, JIRCAS in Japan, IRRI in the Philippines, Moi University in Kenya, ICRISAT in Mali and Niger, and INRAN in Niger. The findings from this research sets the foundation for a molecular breeding program targeting marginal soil areas in southern Mali, Niger and Kenya and other areas of Sub-Saharan Africa to improve food security and farmer’s income.
The specific objectives are:
1. Identify homologs of rice Pup1 that are associated with traits related to P deficiency tolerance in sorghum and also clarify the role of the sorghum Al tolerance gene, SbMATE, in tolerance to low P.
2. Validate genes associated with P deficiency tolerance in sorghum.
1b.Approach (from AD-416):
This project will undertake a comparative genomics strategy based on association analysis to validate the role of sorghum homologs of Pup1 as bona fide P deficiency tolerance genes. Here, Pup1 validation in sorghum will be done within a molecular genetic framework that should allow for the isolation of other P deficiency tolerance genes and their pyramiding in sorghum for exploring additive effects. In addition, this same platform will be used to study a possible role of AltSB in improving P acquisition in sorghum. This project sets the foundation for a molecular breeding program targeting marginal soil areas in Mali, Niger, Kenya and other African NARS to improve food security and farmer’s income.
In FY 2012, we developed new methods to study sorghum root system architecture (RSA) for plants grown in nutrient solution. This will allow us to use our recently developed RootReader 3D root system digital imaging and software system to rapidly capture many 2D images of sorghum whole root systems grown in our specially constructed nutrient solution-based cylinders using plastic grids to support the 3D RSA. Then we can use the imaging software component of RootReader 3D to remove the images of the plastic grids from the root system images and reconstruct the corrected 2D images into a 3D RSA reconstruction. This new system will allow us to study larger, mature root systems in which the roots play a larger role in acquiring limiting nutrients (P and water) from marginal soils.