The effect of asparagus virus infection on asparagus tissue culture

The impact of asparagus virus I (AV-I), a potyvirus, and asparagus virus II (AV-II), an ilarvirus, on micropropagation of field-grown asparagus was studied. Apical shoot tips excised from singly or doubly-infected plants were slow to develop roots and had a 15 to 75% reduction in survival in culture, respectively, compared to those excised from virus-free plants. The four virus infection groups were ranked: virus-free >AV-II>AV-I>AV-I & II for capacity of explants to both root and survivein vitro. Micropropagated plants infected with AV-II exhibited slight reductions in fresh and dry weights, with greater reductions associated with infection with AV-I and double infection, compared to the virus-free controls. Eighty-one virus-infected apical shoot tips yielded 7 (8.6%) virus-free clones, as determined by rub inoculation on indicator plants.     

Protective effect of inactivated virus vaccine on Sendai virus infection in rats

Rats which had received two doses of inactivated Sendai virus vaccine were resistant to intranasal virus challenge. Vaccination was equally effective when administered by intravenous, intraperitoneal, intramuscular, or subcutaneous routes but not the intranasal route. Rats vaccinated intraperitoneally with inactivated Sendai virus vaccine were protected from contact infection. Suckling rats born to vaccinated dams were resistant to challenge infection at 3 weeks of age, but the resistance was not demonstrated after weaning at 4 weeks of age.