The identification of three new viruses isolated from Wisteria and Pisum in The Netherlands, and the problem of variation within the potato virus Y group

Abstract

Three new legume diseases in The Netherlands are described: Wisteria vein mosaic, pea necrosis, and pea leafroll mosaic. In particle size and morphology and in host reaction the virus isolates resembled bean yellow mosaic virus (BYMV), but they were readily distinguishable in several test plants.In recent years several new legume viruses related to BYMV and bean common mosaic virus have been described. Besides, more and more viruses of the potato virus Y group are proving to be naturally infectious to legumes, e.g. lettuce mosaic virus, beet mosaic virus, watermelon mosaic virus, and even turnip mosaic virus, all of which are somehow related to BYMV. To investigate the nature and degree of these relationships, the virus isolates causing the three new legume diseases were compared with a normal strain of BYMV and with pea mosaic virus, clover yellow vein virus, cowpea aphid. borne mosaic virus, two isolates of beet mosaic virus, and lettuce mosaic virus.They were all found to have several hosts and symptoms in common. The differences observed showed a range of gradations only. Unexpectedly, BYMV was found to infect 17 out of 20 non-legumes tested. The Wisteria isolate and lettuce mosaic virus did not produce inclusion bodies, whereas all others did. Often nueleoli were very much enlarged or contained crystals. The pea necrosis isolate produced many nucleolar crystalline needles.Cross-protection tests were of little help in determining mutual relationships.Antisera prepared against the Wisteria isolate, the pea necrosis isolate, and BYMV, and an antiserum against bean common mosaic virus, revealed definite relationships, but also substantial differences. By using the electron microscope the three new isolates were indistinguishable from BYMV, whereas the particle lengths of two isolates of beet mosaic virus were considerably shorter. The isolate of pea mosaic virus had much longer (840 m~x) and more rigid particles.

Three strains of bean yellow mosaic virus: symptoms and accumulation in eight pea cultivars (Pisum sativum L.)

“…Maat, Institute for Phytopathological Research (IPO), Wageningen, The Netherlands; data not shown). The intranuclear inclusion bodies produced by all the virus isolates were identical and similar to those previously described for BYMV (BOS 1969, CHANG et al 1988. Therefore, all the virus isolates represented distinct strains ofa single vims species, namely BYMV.…”

“…The pea strain of BYMV, formerly considered a distinct virus from the bean strain of BYMV and called pea mosaic virus (PMV), causes bright yellow mosaic symptoms, whereas the bean strain of BYMV causes green mosaic symptoms in pea leaves (Bos 1970b, Tapio 1970). Both strains of BYMV infect broad beans inducing similar symptoms and cytoplasmic and nuclear inclusions (Bos 1969, Tapio 1970, Cock-BAIN 1983. The bean and pea strains of BYMV occur naturally in Finland, and these strains may cause a yield loss of up to 62% and 30%, respectively, in peas depending upon the age at which the plants are infected (Tapio 1970 Kielpinski andBlixt 1982, Hovinen 1988, S. Hovinen pers.…”

Pea seed-borne mosaic virus : a review

“…GEOGRAPHICAL DISTRIBUTION HAMPTON & MINK (1975) (Bos, 1970) (M ATTHEWS et al, 1981) and India (T HAKUR et al, 1984). L INDSTEN et al (1976) (MI NK et al, 1969 ;K NE S EK & MINK, 1970) and Switzerland (P EL E T , 1980) and 55 % infected seed in Czechoslovakia (M USIL , 1970 (THAKUR et al, 1984).…”

“…L INDSTEN et al (1976) (MI NK et al, 1969 ;K NE S EK & MINK, 1970) and Switzerland (P EL E T , 1980) and 55 % infected seed in Czechoslovakia (M USIL , 1970 (THAKUR et al, 1984). Above BAGGET, 1970 ;BOS, 1970 ;HAGEDORN, 1974 ;HAMPTON & MINK, 1975 ; § ZIMMER & ALI- KHAN, 1976 ; KRAFT & HAMPTON, 1980 ;PELET, 1980 ;HAMPTON, 1984) Japan (I N O UYE , 1967) and so also the differences in ultrastructural cytology (H AMPTON et al, 1973), initially suggested the existence of strains in PSbMV. However, discrepancies in reported particle lengths for PSbMV were partially resolved by H AMPTON et al (1974) (Bos, 1970) Recently three more pathotypes of PSbMV (namely P-1 and P-4 from pea, and L-1 from lentil) have been characterized on the basis of their infection of pea genotypes (ALCONERO et al, 1986 (1973).…”

“…Above BAGGET, 1970 ;BOS, 1970 ;HAGEDORN, 1974 ;HAMPTON & MINK, 1975 ; § ZIMMER & ALI- KHAN, 1976 ; KRAFT & HAMPTON, 1980 ;PELET, 1980 ;HAMPTON, 1984) Japan (I N O UYE , 1967) and so also the differences in ultrastructural cytology (H AMPTON et al, 1973), initially suggested the existence of strains in PSbMV. However, discrepancies in reported particle lengths for PSbMV were partially resolved by H AMPTON et al (1974) (Bos, 1970) Recently three more pathotypes of PSbMV (namely P-1 and P-4 from pea, and L-1 from lentil) have been characterized on the basis of their infection of pea genotypes (ALCONERO et al, 1986 (1973). They homogenized the infected leaves in an ice-cold mixture of 0.1 M tris-HCI pH9 containing 0.2 0J0 2-mercaptoethanol (150 ml), carbon tetrachloride (40 ml) and chloroform (40 ml) in a Waring blendor and centrifuged the resulting slurry at 10 000 g for 20 mn.…”