Int.J.Curr.Microbiol.App.Sci (2017) 6(6): 2477-2485 2477 Original Research Article https://doi.org/10.20546/ijcmas.2017.606.294 Cytopathological Changes Induced by Yellow Vein Mosaic Virus in Mid-Vein of Infected Okra Plant V.K. Markam 1 *, A.K. Singh 1 , Narayan Lal 2 and Shailendra Kumar 3 1 Department of Plant Pathology, IGKV, Raipur, CG, India 2 Department of Horticulture, 3 Department of Entomology, JNKVV, Jabalpur, MP, India *Corresponding author ABSTRACT Introduction Okra (Abelmoschus esculentus (L.) Moench), belonging to the Malvaceae family, was believed to be originated in tropical Africa (Akanbi et al., 2010). It is an important vegetable crop in the tropical and subtropical region of the world (Kumar et al., 2010). Stem of okra is used for paper making in paper mills. Okra is a good source of vitamin A, B, C and protein, carbohydrates, fats, minerals, iron and iodine (Baloch et al., 1990). Consumption of 100 g of fresh okra fruit provides 20, 15 and 50% of the daily requirement of calcium, iron and ascorbic acid, respectively. This vegetable is attacked by a number of fungi, bacteria, viruses, phytoplsma, nematodes and insects. The total loss, on this vegetable, has been estimated upto 20-30% but if pathogens attack in early age of plant, this loss may increase up to 80- 90% (Hamer and Thompson, 1957). Deshmukh et al., (2011) reported that okra production got major setback due to the severe incidence of yellow vein mosaic virus (YVMV), a gemini virus, in India. The existing commercial varieties/ hybrids are vulnerable to YVMV. It has been observed that degree of resistance varies from locality to locality and season to season. The different virus and vector strains play an important role in expression of disease. Available commercial varieties/hybrids are highly susceptible to the YVMV. The infected plants bear whitish yellow fruits, which are not fit for marketing and therefore, farmers suffer from economic losses. Plants infected at 50 and 65 days, after germination, suffer a loss International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 6 (2017) pp. 2477-2485 Journal homepage: http://www.ijcmas.com In the present cytopathological study, phloem cells of diseased mid-vein retained the Azure A stain indicating the presence of foreign deoxy-ribo-nucleoprotein in comparison to healthy one. Inclusion bodies were found associated with the nucleus of diseased mid-vein phloem cells. Azure A stain imparts red magenta color to the inclusions rich in ribo-nucleoprotein and blue to blue violet color to inclusion rich in deoxy-ribo-nucleoprotein. At higher magnification, inclusion bodies with the diseased mid-vein phloem cells were clearly visible associated with the nucleus in comparison to healthy mid-vein phloem cells of okra plants. Keywords Cytopathological, Azure stain A, Veins, Nucleoprotein. Accepted: 29 May 2017 Available Online: 10 June 2017 Article Info