Screening of clones of Solanum spp. for resistance to potato cyst nematodes, Globodera rostochiensis and G. pallida

Abstract

Screenings were undertaken to assess the reactions of 26 clones of various tuber-bearing Solanum species to Italian populations of the potato cyst nematodes, Globodera rostochiensis Ro2 and G. pallida Pa3. The clones were: three of Solanum acaule, five of S. bulbocastanum, one of S. canasense, three of S. chacoense, two of S. commersonii, three of S. cardiophyllum, one of S. etuberosum, four of S. fendleri, one of S. phureja x S. tuberosum, one of S. multidissectum, and two of S. tarijense. Their reactions were compared with that of S. tuberosum cv. Spunta. Plants of each of the clones were obtained by in vitro culture and were grown in clay pots containing 1000 cm3 of soil infested with 15-20 eggs/g of either nematode species. Nematode development in the roots was assessed about 40 days after transplanting the clones and the dynamics of nematode soil populations were determined about 70 days after transplanting. In general, development of both nematode species was less in the wild species of Solanum. Although no clone was completely resistant, based on the percentage of females and cysts developed on the roots, nematode soil population density, reproduction rate and number of eggs per cyst observed in different tests, clones acl 1A and acl 1E of S. acaule, cph 1C and cph 2D of S. cardiophyllum and fen 1D, fen 1E, fen 2A and fen 2D of S. fendleri could be considered partially resistant to G. rostochiensis. Moreover, clones acl 1A, fen 1D, fen 1E, fen 2A, blb 1E of S. bulbocastanum and chc 1B of S. chacoense were partially resistant to G. pallida.