On the strain distribution of turnip mosaic virus

Abstract

On the strain distribution of turnip mosaic virus Pound and Walker (1945)45) attempted to distinguish insect borne viruses or virus strains attacking cruciferous plants. Since then, similar efforts were made by several other workers, mainly in America24,30,62). According to these studies, it was found that there were two distinct Brassica viruses, namely, turnip mosaic virus and cauliflower mosaic virus, and that Brassica crops were often doubly infected with these viruses24). Workers15,27,38,46,47) in Japan also tried to distinguish the viruses that attacked cruciferous crops: Daikon (Japanese radish, Raphanus sativus L. var. hortensis Backer), Chinese cabbage, turnip, Brassica napus, and other related vegetables. As a result of these studies, several aphid borne non-persistent viruses, which affected crucifers in Japan, namely, turnip mosaic virus, cauliflower mosaic virus, and cucumber mosaic virus, were recognized. Cucumber mosaic virus, however, caused but little damage to these crops, while cauliflower mosaic virus was found only from the vicinity ofTokyo. There were attempts to classify strains within turnip mosaic virus, but they were not very successful.The author collected some 120 isolates of turnip mosaic virus from various parts of Japan, and compared their host range and some of their properties65).It was confirmed that all of the Japanese isolates of the virus collected were able to infect plant showed very mild symptoms with systemic yellow spots or remained apparently healthy, and in the latter case the virus was often localized only within the inoculated leaves. All the Japanese isolates, moreover, produced either only mild symptoms with obscure ringspots on the leaves of young and fast growing cabbage plants, or not at all, often leaving the host plants as symptomless carriers.In any case, no "black ring spot" symptoms were produced.An attempt was made to divide turnip mosaic virus isolates into two strains. The strain that produced mild symptoms on B. oleracea capitata and N. glutinosa was named ordinary strain, and the other that produced severe necrotic ring symptom on B. oleracea capitata and rather severe mosaic on N. glutinosa was named cabbage strain.

Inheritance of resistance to turnip mosaic virus in Chinese cabbage

“…Host resistance, however, is thought to be the only practical and effective means of control and is widely pursued in Asian countries (Ahlawat & Chenulu, 1984 ;Green & Deng, 1985 ;Green, 1991 ;Lim et al ., 1978 ;Sheen & Wang, 1982) . However, occurrence of strains of the virus (Provvidenti, 1980 ;Green & Deng, 1985 ;Li, 1989 ;Chiu, 1988 ;Walkey & Pink, 1988 ;Yoshii, 1963) has greatly hampered such programs (Green & Deng, 1985 ;AVRDC, 1984) .…”

Inheritance and development of EST-SSR marker associated with turnip mosaic virus resistance in Chinese cabbage

“…Many isolates and strains of TuMV have been defined according to their ability to infect certain plant species or cultivars. Primarily, Yoshii (1963) used symptom types on cabbages and Nicotiana glutinosa to distinguish TuMV strains. Symptom types and disease severity indexes were also used by Liu et al (1990) on various Brassica species to define the seven strains (Tu1-7).…”

Genetic and molecular variability of aTurnip mosaic virus population from horseradish (Cochlearia armoracia L.)

“…The first attempts to classify TuMV isolates into groups were made according to symptomatology and host range (Yoshii 1963;McDonald and Hiebert 1975;Choi et al 1980), and pathotypes were identified according to the response of resistant and susceptible differential lines of oilseed rape (Brassica napus var. oleifera) and swede (B. napus var.…”