Detection Of Seed-borne Viruses In Soybean And Common Bean Seeds Conserved In The National Crop GeneBank

A number of plant viruses, which are transmitted by the crop seeds, can infect soybean and food legumes. The viruses in seeds influence not only the quality but also the safety conservation of germplasm seeds in genebank. In this study, 300 soybean and 100 common bean accessions provided by the National Crop GeneBank were screened for seed-borne viruses by serological and molecular biological methods. It is important to understand the virus species and infected status in seeds to get information on viral diseases in defferent sites of seed propagation fields and to analyze the effects of seed-born viruses on germplasm safety conservation. This information will benefit germplasm conservation by taking effective measures to control seed-born viruses in germplasm propagation before conservation in the future.The specific primer pairs, CMV-CP-491F/CMV-CP-491R, amplifying a 491 bp fragment from Cucumber mosaic virus (CMV), were developed based on CP gene of CMV. These primers can be used to detect CMV in infected soybean plants. The complex RT-PCR procedure was established for detecting Soybean mosaic virus (SMV) and CMV. Using this method, it was effective to evaluate germplasm conserved in the National Crop GeneBank with reduced time and cost of detection.In 300 accesions of soybean 74 (24.67 %), 38 (12.67 %), and 14 (4.67 %) were positive to SMV, CMV, and Alfalfa mosaic virus (AMV), respectively. Some accessions were infected by two viruses, such as SMV and CMV,or SMV and AMV.Among the 100 common bean accessions,92 were infected by Bean common mosaic virus (BCMV).The results from this study will be useful in understanding of the status of seed-borne viruses in leguminous crops in the genebank and controlling virus diseases during seed reproduction in field. Based on comparison of the effects of different propagation conditions and viral control measures, a basic suitable technique was proposed, which will benefit to reducing viral diseases in healthy seed reproduction in the future.