Abstract
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 (BC₃), F₂ individuals were evaluated for the resistance phenotype. The ratio of the resistant and susceptible individuals for all F₂ populations fit the expected ratio for resistance being governed by one dominant gene and one recessive gene. Evaluation of the F₃ generation from four susceptible F₂ individuals (two from TxAG-6 × A. hypogaea and two from the BC₃ 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.
Keywords: Arachis hypogaea, durable resistance, Meloidogyne arenaria, peanut, recessive inheritance, resistance genes, root-knot nematode
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