Seed transmission of bean common mosaic virus in phaseolus vulgaris cv Chervona Shapochka

Abstract. Bean common mosaic virus (BCMV) is one of the most harmful and widespread bean viruses. The pathogen can be transmitted with seeds and pollen with a fairly high frequency. With efficient spread by vectors to susceptible crops, even a low level of seed infection can lead to an epidemic situation. In Ukraine BCMV is widespread in all dry bean growing areas and may cause serious crop losses. The aim of this study was to investigate the level of Bean common mosaic virus seed transmission in Phaseolus vulgaris cv Chervona shapochka. Whereas high incidence of seed transmission occurred in direct relation to virus invasion of an immature embryo we tended to follow the virus infection in reproductive tissues of bean. To determine the possibility of vertical transmission of BCMV via pollen, detection of virus RNA in pollen grains by PCR has been carried out. In the study biological methods (mechanical inoculation of viruses, detection of virus infectivity in indicator plants) and molecular biological techniques (total RNA extraction from the plant tissues, reverse transcription polymerase chain reaction) were used. It was shown P. vulgaris cv Chervona shapochka transmitted the BCMV strain in 77 % of the seed produced by infected plants. The date obtained indicates a high level of seed transmission of the virus. According to the findings virus infected seeds have a great value in disease spreading. The viral RNA has been detected in plant generative organs and some components of the seed and flower. Also virus particles were found in pollen grains of Phaseolus vulgaris plants. Diffuse granular viral inclusions were detected in the cytoplasm and nucleus of developing embryo cells.