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Southern root-knot nematode (Meloidogyne incognita) is a major problem in vegetable production in China due to the expansion of plastic tunnel and solar greenhouse.Using resistant cultivars is an effective approach to control the disease.Nine genes,Mi-1 to Mi-9,have been reported and only Mi-1 has been successfully used in tomato breeding.However,Mi-1 is inactive at a temperature above 28℃.In order to identify sources for heat-stable resistance to southern root-knot nematode,53 genotypes of tomato (Solanum spp.) were inoculated with an isolate of M.incognita in the growth chamber at 28 or 32℃ for initial screening.28 lines had less than 25 galls and were considered as resistant candidates.The top 60% (16 in total) of resistant candidates obtained from each temperature were subject to re-evaluation at 32℃ using the same nematode isolate.Three lines ZN17,ZN 48,and LA0385 showed heat-stable resistance with an average of 10 galls or less per plant.LA0385 is a wild species,while ZN 17 and ZN48 are elite breeding lines.These lines were grown in a greenhouse for two seasons,and also showed high resistance with less than 10 galls per plant.Thus they were considered as good sources for breeding resistance to southern root-knot nematode in tomato.