RESISTANCE TO MELOIDOGYNE CHITWOODI, M-FALLAX AND M-HAPLA IN WILD TUBER-BEARING SOLANUM SPP

Over 5000 plants from 64 tuber-bearing wild Solanum spp. have been ind ividually screened for resistance to Meloidogyne chitwoodi, M. fallax and M. hapla. Seedlings were analyzed by means of counting number of e gg masses and resistance was verified by retesting low-scoring plants using stem cuttings. Resistance to both M. chitwoodi and M. fallax was observed in S. bulbocastanum, S. cardiophyllum, S. brachistotrichum, S. fendleri and S. hougasii. Only in S. chacoense and to a lesser exte nt in S. stoloniferum and S. gourlayi differential results between M. chitwoodi and M. fallax were observed. Resistance to M. hapla was foun d in S. bulbocastanum, S. brachistotrichum, S, cardiophyllum, S. arnez ii, S. chacoense, S. tarijense, S. boliviense, S. gourlayi, S. microdo ntum, S. sparsipilum, S. spegazzinii, S. sucrense, S. acaule and S. ho ugasii. The occurrence of resistance in wild Solanum species in relati on to their taxonomic status and the implications for introgression of resistance into S. tuberosum are discussed.