Two bacteriophage isolates specific for Xanthomonas vitians (Brown) Dowson were isolated and some of their biological characteristics were elucidated. These two isolates were similar in morphology, consisting of a polyhedral head of 40nm in diameter, with a very short tail, but were different in their virulence against X. vitians isolates.
Aqueous extracts from the saw dust-rice bran media with grown mycelia of Hymenomycetes (Lentinus edodes or Flammulina velutipes) strongly inhibited tobacco mosaic virus (TMV) infection. The saw dust-rice bran media with grown mycelia were good sources to obtain virus inhibitor from Hymenomycetes.
Inhibitory effect of aqueous extracts from the saw dust-rice bran media with grown mycelia of some edible fungi on tobacco mosaic virus (TMV) infection and multiplication was examined. Edible fungi used were Lentinus edodes (Berk.) Sing., Flammulina velutipes (Curt. ex Fr.) Sing., Lyophyllum aggregatum (Schaff. ex Secr.) Kühner., Auricularia auricula-Judae (Bull. ex Fr.) Quél., Tremella fuciformis Berk., Pholiota nameko (T. Ito) S. Ito et Imai, Volvariella esculenta Bres. and Agricus bisporus (Lange) Sing. The extracts from the saw dust-rice bran media with grown mycelia of L. edodes or F. velutipes strongly inhibited TMV infection. However, no significant effect on TMV muliplication was noted in all extracts examined here.
When midribs of leaves of local lesion hosts were inoculated with TMV, necrosis appeared on the midribs. However, necrosis did not appear on the midribs when they were detached from the leaf tissues and were inoculated with TMV, although TMV multiplied in the midribs. It is postulated that necrotization of the inoculated midribs is caused by some chemical substances, probably by polyphenol or by other low molecular substances which have moved from adjacent green tissues.
When detached leaves of local lesion hosts inoculated with a high concentration of TMV were incubated at 30C for 4-5 days and then transferred to 22C, apparent necrosis did not appear on the inoculated leaves. It is suggested that necrotization does not occur in leaf tissues in which TMV has fully multiplied at 30C, even if they were then transferred to 22C, the optimal temperature for necrotization.