Study On Pathogen Detection Methods Of Citrus HuangLongBing

Citrus Huanglongbing (CHLB) is the occurrence of a serious disaster in the history of citrus plants are called "cancer", it has caused tremendous damage on the global citrus industry. Citrus Huanglongbing is because citrus psyllid between healthy and diseased citrus citrus juice and spread lessons, Citrus citrus psyllid, an important pest month orange, lemon, yellow, paniculata, wolfberry shoots of the Rutaceae. In the citrus Huanglongbing occurrence, it is the only natural insect-borne spread of citrus greening disease. Especially in recent years,it is causing more damage to the citrus industry because of increasing global warming and citrus psyllid to increase the scope of activities. Citrus disaster area has reached more than 80% and more than 40 million plants were cut down. Southern China is citrus industry base, Sihui sugar orange and Deqin Gonggan is listed as the national famous fruit. But the disease has spread to the region, the famous orange sugar is suffering from Huanglongbing invasion, cut or even destroying the garden phenomenon occurred. So that speeding up the research and innovation of control technology is urgent. The disease suspected to be originated from the phloem tissue of the plant, because the pathogen can not be purified and cultured, it has brought many difficulties to the study.Bacterial 16S rDNA is the classification of prokaryotes in one of the most common and effective method, and 16S rDNA sequence is highly conserved, commonly used to phylogenetic relationship was detected among prokaryotes, according to pathogen specific 16S rDNA sequence homology between detection of pathogenic bacteria often exist and disease severity has an important position.Citrus Huanglongbing is currently no effective fungicides, Therefore, strict control citrus psyllid is a critical measure of the current citrus greening disease prevention and control. According to the latest research status at home and abroad, Systematically summarizes the techniques and methods currently used in citrus psyllid prevention measures adopted. The development trend of citrus psyllid prevention prospected. In order to provide reference for prevention citrus psyllid and citrus greening disease prevention and control for citrus growers and grass-roots workers.There is no specific treatment for Citrus Huanglongbing agents, there is no resistance (tolerance) varieties are available. Therefore it is the effective means which the strict quarantine measures must be carried on to provide accurate information for early detection of pathogens, timely excavation to prevent the spread of disease tree. Zhaoqing has developed into the affected area in Guangdong. Its sugar orange are suffering from the invasion in Huanglong bing, the study and solving of CHLB are urgent. It is collecting experimental materials for work from August 2014. The PCR Detection was carried out by using the collecting experimental material in order to find one pair of specific detection primers to effectively reach a easy, fast, stable detection purpose for pathogenic strains.. And the study of RAPD and PCR-RFLP detection research were used in the research field of Citrus Huanglongbing for providing a strong basis for future CHLB research.The main results were as follows:l.On present, the strain of the scientific and accurate detection mainly carried out by PCR technology for relatively fast and stable situation recognition. According to the previous research, relatively specific primers were designed for screened 16SrDNA. The primers could complete the detection and identification for the leaves of healthy and CHLB identified by repetitive validation testing., The genetic similarity could reach to 93% between healthy and diseased leaves by sequencing and gene pool comparison. Therefore, there is a big difference.And a independent PCR detection system had been also built and improved.2.It was found that more than a single pair of primers can make healthy citrus plants and diseased PCR product exhibit differences through uncovered RAPD detection of Citrus Huanglongbing.That were difference nucleotides of C-T, G-T, A-T, C-A between B2 and B10, difference nucleotides of T-A, C-G, G-C, T-C between B11 and B13. It is the reason resulted in the disease on the differences both nucleotides.3.A series of stable data was obtained through studying AFLP molecular detection results to Citrus Huanglongbing. That were large differences between the healthy and diseased plants by the electrophoresis for the detection of diseased plants. It speculated that it is the main difference of pathogenic and health plants. It would lay a foundation for Citrus Huanglongbing molecular evolution data providing and future research.