1987 Volume 53 Issue 4 Pages 454-459
A new disease of melon in greenhouses, characterized by the symptoms of hairy roots and galls, has been observed in Chiba prefecture since 1976. The disease occurs around the year, especially in spring and autumn. Fourteen bacterial isolates obtained from the affected hairy roots and root galls were proved to be pathogenic to melon by needle prick inoculation, exhibiting similar symptoms to those produced by natural infection. The bacterium was also pathogenic to cucumber, watermelon, tomato, rose and others. Fourteen bacterial isolates obtained were quite uniform in their bacteriological characteristics. On the basis of bacteriological characteristics and pathogenicity, the bacterium was identified as the biovar 1 of Agrobacterium rhizogenes (Ricker, Banfield, Wright, Keitt & Sagen 1930) Conn 1942. The name of “hairy root of melon” was proposed for this disease.