Dynamics of dissemination of prunus necrotic ringspot virus in germplasm collection of cherries

摘要

Cultivars of sweet and sour cherries have been collected in the Research and Breeding Institute of Pomology at Holovousy since 1952. An experimental orchard of sweet and sour cherries was established in 1967, and new cultivars were included every year since that then. The assortment was indexed for prunus necrotic ringspot ilarvirus (PNRSV) by ELISA in 1983 for the first time. The ELISA applied was developed by Inotech Diagnostic AG (Switzerland), which also provided antiserum. Samples of young leaves were collected during the last 10 d of May. Altogether, 132 cultivars of sweet cherries and 47 cultivars of sour cherries were tested. In 1989, the collection was transferred to a newly established orchard and the same set of cultivars was tested forPNRSV by ELISA tests in 1992-93. Samples of young leaves and blossoms were taken in May and antiserum obtained from Bioreba (Switzerland). In 1983, 7.9% of sweet cherry and 40.7% of sour cherry trees were infected with PNRSV (11 sweet cherry and 23 sourcherry cultivars). In 1992-93, 11% of sweet cherry and 49.5% of sour cherry trees reacted positively in ELISA, comprising 16 and 45 cultivars, respectively. The increase of the natural dissemination of PNRSV in the germplasm collections of cherries after 10 years reached 3.0% and 8.8% for sweet and sour cherry trees, respectively. Sour cherry cultivars were significantly more susceptible to PNRSV compared with sweet cherry.