Imported maize seeds were planted in a quarantine greenhouse and two seedlings with chlorotic mottle symptoms were observed.The ELISA results showed that the two seedlings reacted positively with antibody against Maiz...Imported maize seeds were planted in a quarantine greenhouse and two seedlings with chlorotic mottle symptoms were observed.The ELISA results showed that the two seedlings reacted positively with antibody against Maize chlorotic mottle virus(MCMV).The positive samples were further identified by RT-PCR method and the 711 bp size target bands were amplified specifically.The similarity range of nucleotide sequence of both RT-PCR product and six MCMV coat protein genes was 97%-99%.The amino acid sequence homology was 97.88%-99.89%.Based on the above results,the virus was identified as MCMV.It was the first time that MCMV was intercepted from imported maize seeds.展开更多
41 fungal isolates with similar morphological characteristics to Leptosphaeria maculans were obtained by the deep-freezing filter paper method from 2100 seeds of Brassica napus imported from Australia.The isolate 8129...41 fungal isolates with similar morphological characteristics to Leptosphaeria maculans were obtained by the deep-freezing filter paper method from 2100 seeds of Brassica napus imported from Australia.The isolate 8129-5 showed a slower growth on PDA at 20℃with growth rate of 2.8 mm/day.The colonies on PDA at 20℃ had an irregular or regular margin with white or grayish white compact aerial mycelium.No diffusible pigment was produced on PDA at 31℃ or in liquid Czapek-Dox media at 20℃.PCR detection showed that the isolate 8129-5 could be amplified by L.maculans-specific primers LmacF/LmacR and got expected product of 331 bp.The sequence analysis revealed that the ITS sequence of isolate 8129-5 had 99.8% identity with L.maculans.Pathogenicity of the isolate 8129-5 was confirmed on cotyledons of rape seed by artificial inoculation compared with typical symptom of L.maculans.Based on the morphological characteristics,PCR detection and the result of pathogenicity test,the isolate 8129-5 was identified as L.maculans.展开更多
文摘Imported maize seeds were planted in a quarantine greenhouse and two seedlings with chlorotic mottle symptoms were observed.The ELISA results showed that the two seedlings reacted positively with antibody against Maize chlorotic mottle virus(MCMV).The positive samples were further identified by RT-PCR method and the 711 bp size target bands were amplified specifically.The similarity range of nucleotide sequence of both RT-PCR product and six MCMV coat protein genes was 97%-99%.The amino acid sequence homology was 97.88%-99.89%.Based on the above results,the virus was identified as MCMV.It was the first time that MCMV was intercepted from imported maize seeds.
文摘41 fungal isolates with similar morphological characteristics to Leptosphaeria maculans were obtained by the deep-freezing filter paper method from 2100 seeds of Brassica napus imported from Australia.The isolate 8129-5 showed a slower growth on PDA at 20℃with growth rate of 2.8 mm/day.The colonies on PDA at 20℃ had an irregular or regular margin with white or grayish white compact aerial mycelium.No diffusible pigment was produced on PDA at 31℃ or in liquid Czapek-Dox media at 20℃.PCR detection showed that the isolate 8129-5 could be amplified by L.maculans-specific primers LmacF/LmacR and got expected product of 331 bp.The sequence analysis revealed that the ITS sequence of isolate 8129-5 had 99.8% identity with L.maculans.Pathogenicity of the isolate 8129-5 was confirmed on cotyledons of rape seed by artificial inoculation compared with typical symptom of L.maculans.Based on the morphological characteristics,PCR detection and the result of pathogenicity test,the isolate 8129-5 was identified as L.maculans.
