Institution:Board of Regents of the University System of Georgia on behalf of the University of Georgia Cooperative Extension Service and University of Georgia Research Foundation, Inc.
Region:Southeast (GA, FL, AL)
Project Fiscal Year:2014
Report Received Date:
Project NPB Budget:$30,000
Root-knot nematodes and late leaf spot are a very damaging to the peanut crop. Resistance to late leaf in peanut cultivars is limited, and currently only a single source of resistance to root-knot is available (originating from the wild species A. cardenasii, and available in cultivars like Webb, and H/O Tifguard). There are serious concerns that this root-knot resistance could be broken. In this project we investigated new sources of resistance to root-knot nematode and late leaf spot from the wild species A. stenosperma. This was done by studying plants derived from a cross involving peanut (A. hypogaea) and A. stenosperma.
Peanut has two sets of chromosomes that originally derived from two wild species, one contributing "Achromosomes" and the other "B-chromosomes". A. stenosperma has only A-chromosomes, therefore to be able to cross with peanut, it needed to first be crossed with a B-chromosome species (in this case a species called A. batizocoi was used). These hybridizations were carried out before the beginning of the project.
In this project, a population of 230 plants specially structured for genetic analysis, from the cross A. hypogaea x (A. batizocoi x A. stenosperma) was tested for resistance to root-knot nematode and late leaf spot using controlled quantifiable methods. This information will be used together with DNA-typing information and genetic mapping to identify chromosomal regions that confer resistance and to develop molecular markers to aid in the production of new resistant peanut varieties.