Virus disease is the most common type of disease in Passiflora spp. and is also known as a phloem disease . Once infected by the virus disease, it can cause the whole plant of Passiflora spp. not to bloom and fruit, resulting in a continuous reduction in the yield . Unfortunately, it is well-known that the antiviral agents that are currently available on the market cannot effectively control virus disease, and the mechanism of action between antiviral agents and virus disease has not been clarified, resulting in the research on the control of Passiflora spp. virus disease becoming difficult.
In this study, a laboratory anti-CMV activity screening model for CMV disease of Passiflora spp. seedlings was first established and the effects of COS, DFL, and Ning on CMV virulence rates in Passiflora spp. seedlings were determined and the results were listed in Table 1. Table 1 showed that the virulence rate and anti-CMV activity in Passiflora spp. treated with COS were 50.00% and 45.48%, respectively, which were superior to those of DFL (66.67% and 27.30%, respectively) and Ning (83.30% and 9.17%, respectively), demonstrating that COS could effectively control the CMV disease in Passiflora spp. seedlings. Meanwhile, to study the control efficiency of COS, DFL, and Ning on the control of CMV disease of Passiflora spp., a preliminary study on the control of Passiflora spp. CMV disease was conducted through field efficacy trials. As shown in Table 2, on the 7th day after the first, second and third spraying, COS was effective in reducing Passiflora spp. CMV disease in the field (the average control efficiency is 47.35%) relative to those of DFL (40.93%) and Ning (33.82%). The study results demonstrated that COS could be used as a potential plant immune inducer to control the Passiflora spp. CMV disease in the future.
TABLE 1 Results of Laboratory Anti-CMV Activity of COS, DFL, and Ning.
TABLE 2 The control effificiencies of COS, DFL, and Ning against Passiflflora spp. CMV disease
Reference:Chitosan oligosaccharide as a plant immune inducer on the Passiflora spp. (passion fruit) CMV disease