Damage Investigation Of CTV-Stem Pitting And Screening Of Mild CTV Strains In Hunan

Hunan is one of the most important citrus producers in China, which citrus industry by rapid development in recent years, area and production have jumped first in the country. Due to widely utilization of CTV-resistant trifoliate rootstock, up to now CTV has not caused severe damages to the citrus industry. However, as the strong CTV strain's infection, some economic losses in citrus have been demonstrated. CTV can be carry with aphides, lead to the tree of innocuity be easy to infected, so it's hard to control. Present study aims at the find out of damage situation in Hunan, use the RT-PCR technique and the analysis of DNA sequences, selected mild CTV strains forPractice MSCP in Hunan.1. Preliminary investigation on stem pitting of CTV in citrus varieties of theHunan citrus industry county found that some of the highly virulent orchard plants has been completely lost production value, trees extremely recession, branches Sparse yellow serious depression stems obvious point, even no fruit, and the extent of their victims with the passage of time.2. By RT-PCR method of sequencing the toxicity of its type conducted research and found that all regions of the recession lines and did not appear very specific areas of specificity, this may be the current county and the city of species frequent exchanges began with , But it has not been good virus-free varieties by grafting to the local recession breeding lines to other places, and the recession itself with specific lines, the local department may be attenuated to other places will become of the severe isolate.3. Preliminary screening to mild strain of CTV. Quoted Sambade design primer, through RT-PCR method to identify the virus samples of the sequence, At the same time, measured the corresponding sequence of amino acid sequence analysis, CTV mild strain of the basis for further screening . At the same time use the method of ScaI and TaqI enzyme digestion screening to mild strain of CTV.4. Mild Strain Cross Protection experiment. Use of three kinds of commonly used instructions of the CTV to research Mild Strain Cross Protection experiment.