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 the second year of this project, we have used genetic and molecular methods to study sorghum genes we identified in the previous year, that are homologs to the phosphorous (P) uptake gene in rice, Pup1, which is a protein kinase. The rice Pup1 gene leads to improved performance for rice lines on soils deficient in phosphorous. We have found that possibly two different maize pup1 genes play a role in improved maize yields on low P soils.