Resistance of Lathyrus Species and Accessions to the Northern Root-knot Nematode, Meloidogyne hapla

Abstract

The leguminous plant genus Lathyrus contains many species useful for soil conservation and reclamation. Some of these species may also have vaIue in the United States for forage production. The extent of genetic variation among Lathyrus populations in reaction to most disease pathogens is not known. We examined 28 USDA Agricultural Research Service Plant Introduction accessions representing 16 Lathyrus species for their ability to tolerate attack by the northern root-knot nematode, Meloidogyne hapla. There were differences in the percentage of root tissue galled and in the nematode reproductive index among species and among accessions within species. Root biomass of infected plants was significantly less than that of uninfected plants of the same accession. Accessions of L. ochrus and L. tingitanus were susceptible to M. hapla, whereas L. latifolius, L. sylvestris, and L, hirsutus were resistant. The variation among Lathyrus spp. in root galling and reproductive indices ofM. hapla warrant the inclusion of these traits in Lathyrus breeding programs. Key words: alfalfa, flatpea, forage, germplasm, grasspea, Lathyrus, legume, Meloidogyne hapla, nematode, pathogenicity, peavine, perennial pea, vetchling.