Transmission And Molecular Detection Research Of Acidovorax Avenae In Melon And Xanthomonas Axonopodis In Anthrium

Melon Bacterial Fruit Blotch (Acidovorax avenae subsp.citrulli) and Anthurium Bacterial Leaf Blight (Xanthomonas axonopodis pv.dieffenbachiae) are worldwide destructive disease that cause significant economic losses for melons industry and anthurium industry. In order to provide a basis for integrated control,the channel of disease spread,and detection technologies were studied in this paper.1.It has been clarified that bacteria-contaminated seeds and soil, pollen tube and splashing water drops are the major source of bacterial fruit blotch. Seed soaking、drip inoculation、mixing bacterial fruit blotch pathogens with soil and splashing water drops were used to inoculated bacterial fruit blotch pathogen in healthy melon seeds, stigma, soil and seedlings, the transmission of bacterial fruit blotch was studied.The results indicated that bacterial fruit blotch can transmison by seed soaking and pollen tube;Melon seedlings planted in contaminated soil demonstrated symptoms after emergence13d,With the growth of seedlings, the situation would get worse, the morbidity and disease index of the worst seedlings were69.13%and25.72;bacterial fruit blotch pathogens can spread by water splashing, the closer the more serious, the morbidity and disease index were63.34%and47.12.2.We are clear about infected soil, and splashing water drops are the main transmissions of bacterial leaf blight. Inoculate bacterial leaf blight pathogens on sterilized soil and splashing water drops were used to study the transmission of bacterial leaf blight.The results showed that Anthurium plant in contaminated soil displayed symptoms after transplanted14d, with the increase of transplant days, the incidence would getting more serious, the morbidity and disease index of the worst seedlings were84.74%and72.31;bacterial leaf blight pathogens can spread by water splashing, the more recent onset,the worse, the morbidity and disease index were75.00%and55.54. 3.We have created selective media and nested-PCR to identify seeds infected by bacterial fruit blotch pathogens. Selective medium (ASCM) was used to separation and detection pathogens on the contaminated seed, two primer pairs were referenced to amplify bacterial fruit blotch pathogen from ASCM liquid by nested-PCR. The results indicated that selective medium can specificity separation, training and enrichment bacterial fruit blotch pathogen; SEQ10/SEQ12, SEQ11/SEQ12and nested-PCR could amolify262bp,241bp and241bp fragment only from Acidovorax avenae. In conventional PCR,the sensitivity of detection was1.92×10-4mg/L and1.92×10-3mg/L for both primes,in the nested-PCR the detection limit was1.92×10-6mg/L. The lowest ASCM liquid concentration that can be identified by nested-PCR was2×105cfu/ml.4. A nested-PCR detection technology was established to identify plants infected by bacterial leaf blight. Two primer pairs were referenced to amplify bacterial leaf blotch pathogen from the plant roots, stems, leaves by nested-PCR. The results showed that PXadU/PXadL,NXadU/NXadL and nested-PCR could amolify1570bp,785bp and785bp fragment only from Xanthomonas axonopodis, respectively, no amplification product was observed from healthy plants. In conventional PCR,the sensitivity of detection was1.23×10-5mg/L and1.23×10-3mg/L for both primes, in the nested-PCR the detection limit was1.23×10-1mg/L.The sensitivity of detection of infected plants DSI reached the samples with DSI of16.6.This is the first clarifying the main transmission of bacterial fruit blotch and bacterial leaf blight. Established selective media and nested-PCR to identify seeds infected by bacterial fruit blotch pathogens,A nested-PCR to detection anthurium plants infected with bacterial leaf blight was created,which is contribute to the rapid disease prediction and early prevention.