北京地区番茄叶霉病菌生理小种及分化规律的研究

叶霉病（Ｆｕｌｖｉａｆｕｌｖａ（Ｃｏｏｋｅ）Ｃｉｆｅｒｒｉ）是保护地番茄上的主要病害，对叶霉病菌生理小种及分化规律的研究，有助于了解该病菌的分化组成情况，为抗病育种有针对性地合理选择使用抗源提供依据。１９８４－１９９０年以前，北京地区叶霉病菌以生理小种１．２和１．２．３为主，Ｃｆ４为免疫型抗病基因，１９９０年，侵染Ｃｆ４基因的生理小种群１．２．４．２．４和１．２．３．４出现，使含Ｃｆ４基因的双抗２

Studies on Physiological Races of Tomato Leaf Mould and Their Differentiation in Beijing

Leaf mould (Fulvia fulva Cooke Ciferri)is one of the serious diseases on tomato under protective cultivaion (greenhouse and plastic house).In the program of tomato breeding for resistance to leaf mould,it is important to determine the extent of physiological races of leaf mould.Between 1984 and 1990,the races 1.2 and 1.2.3 were found in Beijing.The gene Cf 4 was immune from those races.So a resistant variety (F 1) Shuang Kang.2 with Cf 4 was first introduced in tomato production.In 1990,that hybrid was attacked by the new races of 1.2.4,2.4 and 1.2.3.4.Another hybrid Jia Fen.15 with Cf 4 and Cf 5 was developed.It was resistant to the new races found in 1990.Although the six races had no obvious difference in virulence from those races in 1990,the virulence of a few isolations strengthened in a certain degree.The gene Cf 5 came to show no more immunity.Occassionally,a little amount of the mould could be found on the host plants with Cf 5.The breeders have to pay more attention to this matter.