Research On Seed-borne Characteristic Of Cucumber Mosaic Virus Isolates Of Hunan

Cucumber mosaic virus(CMV)is one of the common virus on Cucurbitaceae crops,as well as a seed-borne virus with serious dangers.It is reported that CMV can transmit through pepper seeds,as CMV transmit through seed in cucumber have not been reported,therefore,in this paper,the biological characteristics of CMV isolates as well as the complete sequences are studied,seed-infection and seed-transmission rate of the different subgroups of CMV in cucumber seeds are analysised.The main results are as follows:1.The CMV isolate is named CMV-Scs after isolation and purification.The symptoms of the corresponding differential hosts are showed after inoculating 12 kinds of plant with CMV-Scs,and CMV-Fny which is belong to the subgroup IA of CMV are showed symptoms of biological differences.The CMV ordinary RT-PCR detection method,for CMV detection in cucumber seeds with the seed-infection rate and seed-transmission rate is optimized,it will be a unified,reliable method.2.Before the fruiting period of the cucumber of two times,the detection of CMV-Scs and CMV-Fny infection rates in leaves and pollen are all 100%,and it showed that the seed-infection rate of CMV-Scs is all 100%,while using RT-PCR method after seeds harvested,and the seed-infection rates of CMV-Fny are only 66.7%and 74.4%.3.In grown-out tests of two times,no any distinct infected symptoms are produced during the growth process of cucumber seedlings.The average germination rate of cucumber seeds infected CMV-Scs is 17.3%?and the seed-transmission rates of seeds in cucumber infected CMV-Scs are 80%and 90%for the two times.The average germination rate of cucumber seeds infected CMV-Fny is 31.1%,and the seed-transmission rates of seeds in cucumber infected CMV-Fny are 40%and 46.2%for the two times,while the germination rate of healthy cucumber seeds is 87.5%.4.Through the design of specific primers,we obtain the w-hole complete sequences of CMV-Scs,the sequences lengths of different RNome of CMV-Scs is RNA1 3380 bp,RNA23058 bp and RNA3 2227 bp.RNA1 and RNA2 complete sequence phylogenetic tree figure show that CMV-Scs is most similar with subgroup IB in sequence homology,with the comprehensive of RNA3,CP and MP complete sequences clustering analysis,it suggests that the CMV-Scs belongs to the CMV subgroup IB.