Isolation and identification of virus dsRNA from strawberry plants.

摘要

The analysis of virus genome is based on nucleic acid isolation. The aims of this study were to develop a method for isolation and identification of virus double-stranded ribonucleic acid (dsRNA) and to elucidate the nucleotide sequences of strawberry virus. Using the modified method, virus dsRNA was extracted from strawberry virus indicator plants (Fragaria virginiana and F. vesca) and cultivated strawberry plants (cultivars Hokowase, Nuobinka, Governor Simcoe, Brandenburg and Tian 5) and detected using agarose gel electrophoresis with ethidium bromide staining and reverse transcription-polymerase chain reaction (RT-PCR). The quantity of virus dsRNA varied among strawberry cultivars. Field experiments were conducted in Shenyang, China. The quantity of dsRNA from in vitro plantlets was higher than that from the young leaves of field plants. For the field-grown plants, there was more dsRNA in the young leaves. Virus dsRNA extracted from strawberry plants was resistant to deoxyribonuclease I (DNase I), but evidently, it became resistant to ribonuclease A (RNase A) only in the presence of 0.5 M NaCl. Its bands in agarose gel could be readily recycled using an agarose gel DNA purification kit. With RT-PCR, the segments of both strawberry mottle virus and strawberry mild yellow edge virus genomes were amplified by using the virus dsRNA recycled from gel or treated with DNase I/RNase A as templates. The system developed for dsRNA isolation and identification in strawberry plants laid a sound foundation for the work on genome analysis of strawberry virus isolates in China..