Complete Genome Sequences Of CLBV And AYRSpV And Study On Infection Of Kiwifruit

Occurrence and damage of virus diseases are important factors affecting the development of deciduous fruit tree industry in China.Identification,detection and sequence analysis of virus species can provide theoretical basis for the research on the occurrence rule and control technology of viral diseases.In this study,based on the results of high-throughput sequencing,the molecular characteristics of Citrus leaf blotch virus(CLBV)infecting Malus spectabilis and Actinidia yellowing ringspot virus(AYRSp V)infecting kiwifruit,and the infection status in kiwifruit of these two viruses,were studied.The main results obtained are as follows:(1)Through lncRNA sequencing combined with RT-PCR amplification,three molecular variants of CLBV were obtained from Malus spectabilis in Xinyang,Henan,and the complete genome sequence of CLBV Malus isolates was determined for the first time.The nucleotide sequences of Rd Rp and CP of these three molecular variants showed 73.2%-88.3% and 72.1%-93.9% nt identity with the corresponding sequences of reported CLBV isolates,respectively.Meanwhile,the amino acid sequences of Rd Rp and CP of these three molecular variants displayed 79.3%-98.0% and 78.5%-97.8% aa identity with the corresponding sequences of reported CLBV isolates,respectively.RTPCR detection for 213 kiwifruit samples from eight different provinces and cities disclosed that the occurence frequency of CLBV was 16.0%.(2)The complete genome sequences of Two isolates of AYRSp V were obtained from Actinidia sinensis in Yichun,Jiangxi by small RNA sequencing combined with RT-PCR amplification.RT-PCR was used to detect 82 field samples of kiwifruit from 5provinces(cities)including Chongqing,Jiangxi,Guangxi,Hubei,and Fujian,and the detection rate of AYRSp V was 15.9%.Through specific primer design and RT-PCR amplification,the CP sequences of nine isolates of AYRSp V were obtained,all of which were 666 nt in full length,and their nucleotide and amino acid sequences were 92.6%-100% and 93.2%-100%,compared with AYRSp V-Meixian.The results show that the CP sequence variation of different isolates of AYRSp V is small.In this study,the whole genome sequences of three molecular variants of CLBV and two isolates of AYRSp V were determined,the RT-PCR detection technology of these two viruses was established,and the bands of CLBV and AYRSp V in field samples from different kiwifruit producing areas were determined.The results provide new useful information for in-depth understanding of the molecular biological characteristics of kiwifruit virus China.