Identification of Citrus medica var. sarcodactylis Infected with Citrus Huanglongbing / 中国实验方剂学杂志

ABSTRACT

Objective:To analyze and compare different samples in many aspects to identify Citrus medica var. sarcodactylis infected with Huanglongbing(HLB) timely and accurately, in order to prevent and control the disease in time. Method:HLB was identified through character analysis, reverse transcription-polymerase chain reaction(RT-PCR), enzyme digestion reaction and Real-time PCR. Result:In terms of characters, there were typically variegated yellow leaves and relatively small fruit, even with deformity but without " red nose fruit" among C. medica var. sarcodactylis infected with HLB. All of these can be used as the basis for the preliminary identification of HLB in the fields. According to the RT-PCR test results and enzyme digestion reaction, when the primer was OI1/OI2c, there was specific band of 1 160 bp, which could be cut into 520 bp and 640 bp by Xba I enzyme. These results were consistent with the characters of other citrus plants infected with HLB. According to the Real-time PCR detection results, C. medica var. sarcodactylis infected with HLB had amplification curves and dissolved peaks, with the melting temperature was 82 ℃ and Ct between 24.6 to 28.2, while the normal plants were not amplified. Conclusion:Character analysis can be used to roughly distinguish HLB in the fields, but with a certain subjectivity. RT-PCR or Real-time PCR can be used to identify C. medica var.sarcodactylis infected with HLB in a timely and accurate manner, and qPCR detection is more sensitive and quantitative. Through the combination of character analysis and molecular identification, C. medica var.sarcodactylis infected with HLB can be determined more timely and accurately.