Identification of Additional QTLs for Resistance to the Root-knot Nematode (Meloidogyne arenaria (Neal) Chitwood) in an Introgression Population of Peanut (Arachis hypogaea L.)

The root-knot nematode can cause significant yield losses in fields where it is present.  Markers to one or possibly two closely-linked genes introgressed from wild species of peanut have been identified previously, but evidence for the presence of additional, unlinked genes in the wild species had not been paralleled by evidence of introgression into the cultivated species.  An advanced backcross population from a cross between Florunner and TxAG-6, where TxAG-6 is the synthetic amphidiploid [A. batizocoi x (A.cardenasii x A. diogoi)]^4x, was screened for response to root-knot nematode.  A total of 233 BC₃F₁ plants were inoculated in the greenhouse with eggs of M. arenaria, and the number of eggs produced on roots was counted.  Data transformed to a normal distribution were analyzed by several methods, and the experiment was validated by re-identifying markers for the known resistance gene in all analyses.  Results also suggested the possible introgression of two additional A-genome resistance genes, and one derived from the B-genome.