Root-knot Nematode Resistance in Arachis Glabrata1

Abstract

Abstract Peanut root-knot nematode (Meloidogyne arenaria race 1) is an important pest of cultivated peanuts (Arachis hypogaea L.). Experimental data do not exist, however, to indicate whether this nematode might be a potential pest of peanuts grown for forage production. Florigraze and Arbrook, two recently released cultivars of rhizoma peanut (Arachis glabrata Benth.) and P.I. 446898 (Arachis spp.) with perennial forage potential, were evaluated for their interaction with M. arenaria race 1, M. javanica, and M. incognita races I and III. Individual plants, grown in 150 cm3 ConetainersR, were inoculated with 3,000 eggs of one of the four Meloidogyne spp. populations. After three months gall and egg mass scores and soil-nematode counts were determined for each plant sample. A second long-term experiment evaluated Florigraze that was repeatedly inoculated with high levels of root-knot nematodes. Both rhizoma peanut cultivars were highly resistant to all root-knot nematodes tested; Florigraze appeared to be immune. P.I. 446898 was intermediate between the rhizoma peanuts and the susceptible alyceclover check. This is the first known report of such high levels of Meloidogyne arenaria resistance in Arachis spp. Further screending of A. hypogaea material can be justified based on these results and Vavilov's “Law of homologous series”. If no resistance is found in A. hypogaea, A. glabrata may provide a source of resistance that may be transferred to A. hypogea through hybridization.