Stability of Peanut Germplasm Resistance to Root-Knot Nematode (Meloidogyne hapla Chitwood)

During 1998～2000, 10 selected resistant/tolerant peanut germplasms to root-knot nematode (Meloidogyne hapla Chitwood) and 20 selected elite lines under natural infested field condition were evaluated for their stability of resistance in artificial nursery garden, microplot trails, and pot inoculation test. The overall evaluation of results indicated that D015, D035, D040, and D099 were middle resistant, and D002, D029, D041, D049 were stable tolerant to peanut root-knot nematode disease. Among the screened materials, two high resistant genotypes in natural field were middle resistant, four of the 8-middle resistant/tolerant genotypes should be middle or high susceptible, and only one middle resistant and two tolerant materials were selected from the 20 elite lines for their stability. The materials with stable resistance were suitable to be utilized in peanut resistant breeding programs. However, traditional nematode resistance identifying methods are subjected to be affected by environment conditions, and need a long period, so new techniques should be developed to identify nematode resistance of peanut in early generation.