Disinfection of pepper seed infected with different strains of capsicum mosaic virus by trisodium phosphate and dry heat treatment

Disinfection of pepper seed infected with capsicum mosaic virus (CaMV) by immersion in 100 g/1 Na₃ P0₄ solution was compared with dry heat treatment at 76°C. The virus content of the seed varied with the CaMV strains used to infect the pepper cultivars and the time of harvest of seeds from infected plants. Immersion times in Na₃PO₄ had to be increased from 15 min to 2 h to obtain near-complete virus inactivation; these treatments had no effects on germination.
Heating seed in an oven at 76°C for 3 days following a waiting period of 3 months after harvest always eliminated all the virus present, but adversely affected germination. This resulted in delayed emergence and a reduction in the number of seedlings suitable for further raising. The viability of heat-treated seeds also decreased with continued storage after treatment.
There were inconsistent differences in germination of seed from healthy plants and plants infected with the CaMV strains P8 or P11. The possibility of internal seed infection and practical consequences are discussed.