A Recessive Gene for Resistance to Meloidogyne arenaria in Interspecific Arachis spp. Hybrids
A single dominant gene for resistance to Meloidogyne arenaria was identified previously in two peanut cultivars, Arachis hypogaea 'COAN' and 'NemaTAM'. The interspecific Arachis hybrid TxAG-6 was the source of this resistance and the donor parent in a backcross breeding program to introgress resistance into cultivated peanut. To determine if other resistance genes were present in TxAG-6 and derived breeding populations from the third backcross generation (BC[sub3]), F[sub2] individuals were evaluated for the resistance phenotype. The ratio of the resistant and susceptible individuals for all F[sub2] populations fit the expected ratio for resistance being governed by one dominant gene and one recessive gene. Evaluation of the F[sub3] generation from four susceptible F[sub2] individuals (two from TxAG-6 × A. hypogaea and two from the BC[sub3] population) confirmed that a recessive gene for resistance to M. arenaria was present in each of the tested populations. The identification of a second gene for resistance in the A. hypogaea germplasm may improve the durability of the resistance phenotype.
arachis hypogaea; durable resistance; meloidogyne arenaria; peanut; recessive inheritance; resistance genes; root-knot nematode