Occurrence Of Root-knot Nematodes On Vegetables In Hunan And Screening Of Tomato Varieties With Resistance To Meloidogyne Incognita

Investigation on occurrence and damage of vegetable root-knot nematode diseases were carried out in Hunan. The sample was coll ected,isolated and then identified by traditional morphological chara cteristics. The present study was conducted to identify the resistance against Meloidogyne incognita in 10 tomato materials and 12 toma to varieties from hunan district, including Baiguoqiangfeng,Houpiza ofeng,Xiangfenyihao,Hongshichua,Americandahong,Europeanda hong,Jiaxinhongyang,Yuanyangdahong,Xinyouzaofeng,Taiwanfux ingtomato,Shanghai908 and Shanghai903. Susceptible variety lichun was choiced as check variety. The result and conclusion as followe d:(1)Vegetable root-knot nematode diseases have caused serious d amage in most district of hunan. Annual incidence rate of the bloc k reached more than 80%, the incidence rate of plants 50%-100%. At Greenhouse, Cucurbitaceae and Solanaceae are the most serious disease of all the vegetables, especially cucumbers, tomatoes, but p eppers less.(2)The collected root-knot nematode were isolated and identifie d. The morphology value and the perineal pattern were in accordan ce with those of Meloidogyne incognita. Meloidogyne incognita formed the majority, with the detective rate 87%. So the predominant species was Meloidogyne incognita in hunan.(3)The disease index of ten tomato varieties were all more tha n 90. All the tomatoes were susceptible to Meloidogyne incognita. Baiguoqiangfeng,Houpizaofeng and Xinyouzaofeng grew weak, wit h low survival rate. Xiangfenyihao,Shanghai908 and Taiwanfuxingt omato didn't grow well. Hongshichuan,Americandahong,Europeand ahong,Shanghai 908,Jiaxinhongyang,Yuanyangdahong grew luxur iantly, with high survival rate. The disease index of Hongshichuan,Americandahong,Europeandahong,Jiaxinhongyang,Xiangfenyihao a nd Taiwanfuxingtomato were over 90, Baiguoqiangfeng,Houpizaofe ng and Xinyouzaofeng lower. All of them were highly sensitive var ieties to M. incognita. Shanghai908 was medium sensitive variety. S hanghai903 was medium resistant variety. According to DPS multipl e range test, there was significant resistance difference between vari eties Shanghai 908,Shanghai 903,Baiguoqiangfeng,Houpizaofeng and the check variety lichun(p<0.01). Besides, there was also signifi cant resistance difference between Shanghai 908,Shanghai 903 vari eties and Baiguoqiangfeng,Houpizaofeng varieties(p<0.01).