Abstract
Chrysanthemum stunt is one of the most serious diseases of chrysanthemums. We investigated the transmission of chrysanthemum stunt viroid (CSVd) in chrysanthemum seeds by infecting parental plants with low and high CSVd concentrations. Seedlings(%) infected with a high CSVd concentration was between 34% and 82% when either of the parent was infected with a high CSVd concentration, and these ratios were 6% when both the parents were infected with a low CSVd concentration.
Infected seedlings with high-concentration of CSVd were grafted onto CSVd free“piato”and “Seiaishisu-pink” with low-concentration of CSVd. After 2 months, CSVd was detected by RT-LAMP in all grafted chrysanthemums. In the CSVd detected plants, “Seiaishisu-pink”, the plant height was shorter, their leaves were smaller, and the attitude of petioles was very strongly upwards, than those of control. CSVds of infected seedlings had high infectivity and pathogenicity, and they were transmitted through seeds and pollen grains of chrysanthemums.
