~ 1852 ~ Journal of Pharmacognosy and Phytochemistry 2018; 7(5): 1852-1854 E-ISSN: 2278-4136 P-ISSN: 2349-8234 JPP 2018; 7(5): 1852-1854 Received: 22-07-2018 Accepted: 24-08-2018 Soberwell Rynjah Department of Vegetable Crops, HC&RI, TNAU, Coimbatore, Tamil Nadu, India VA Sathiyamurthy Department of Vegetable Crops, HC&RI, TNAU, Periyakulam, Tamil Nadu, India T Saraswathi Horticultural Research Station, Kodaikanal, Tamil Nadu, India S Harish Department of Plant Pathology, AC&RI, TNAU, Madurai, Tamil Nadu, India Correspondence Soberwell Rynjah Department of Vegetable Crops, HC&RI, TNAU, Coimbatore, Tamil Nadu, India Field screening of okra ( Abelmoschus esculentus L. Moench) genotypes against okra yellow vein mosaic virus disease Soberwell Rynjah, VA Sathiyamurthy, T Saraswathi and S Harish Abstract Yellow Vein Mosaic Virus (YVMV) is a major disease in okra which is transmitted by the vector whitefly (Bemisia tabaci). Five diverse okra genotypes namely AE 64, AE 65, AE 66, Kashi Pragati and VRO 106 were crossed in full diallel fashion. A total of twenty five cross combinations (five parents and twenty hybrids) were raised in randomized block design in two replications during the Rabi - Summer, 2015 at Department of Vegetable Crops, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore. The severity of YVMV disease was recorded and the percent disease incidence (PDI) was calculated. The genotypes AE 64, AE 65 and AE 66 were found to be immune to the disease which could be exploited for further breeding programme due to their resistant disease reaction towards YVMV. Among the hybrids, the cross combinations of AE 64 x AE 65, AE 64 x AE 66, AE 65 x AE 64, AE 65 x AE 66 and AE 66 x AE 64 did not express any disease symptoms whereas the susceptible check COBhH 1 showed highly susceptible reaction. Keywords: Okra, Percent Disease Incidence (PDI), whitefly, Yellow Vein Mosaic Virus (YVMV) Introduction Okra (Abelmoschus esculentus (L.) Moench), is an economically important vegetable crop grown in tropical and sub-tropical parts of the world. It is one of the important member of Malvaceae family having higher chromosome number of 2n=8x=72 or 144 and polyploidy in nature. Though okra is native of tropical Africa, it is a priced vegetable grown for its tender fruits in India. Okra has good nutritional value, particularly high content of vitamin C (47 mg/100g), vitamin A (0.18 mg/100g), calcium (84 mg/100g), iron (1.20 mg/100g) and fibre (1.70 g/100g) in the edible fruit (Benchasri et al., 2012) [4] . In Okra, yellow vein mosaic virus disease (YVMV) is the most devastating disease which is transmitted by whiteflies (Bemisia tabaci) (Magar and Nirmal 2010) [9] . YVMV belongs to the genus Begomovirus, family Geminiviridae. In India, the occurrence of this disease was first reported by Kulkarni (1924) [8] in the province of Bombay. A plant with yellow vein mosaic virus has yellowish mosaic on the leaves, prominent yellow veins and crinkled leaves. If infection is severe, plants become stunted with poor quality pods and upto 100 per cent infection in the field oocur with yield losses ranging from 50 to 94 per cent depending on the stage of crop growth at which infection occurs (Sastry and Singh, 1974) [14] . The application of pesticides for controlling the whiteflies is commonly practiced by the farmers but this poses a threat and pesticide residues to the consumers. Uprooting of infected plants is also done when infection is heavy in the field. The only practical solution for this problem is to develop resistant cultivars, identification and transfer of genes for resistance to YVMV from related wild species to susceptible high yielding cultivated varieties (Jambhale and Nerkar, 1985) [6] . Therefore, the present study aims at searching the source of resistance towards yellow vein mosaic virus resistance. Material and methods Plant material: Five diverse okra genotypes namely AE 64, AE 65, AE 66 collected from Tamil Nadu Agricultural University, Coimbatore, Kashi Pragati and VRO 106 collected from Indian Institute of Vegetable Research, Varanasi were used for the present study. They were maintained through selfing during kharif season of 2014 and were crossed in full diallel mating design to develop twenty F1 hybrids during Rabi- summer of 2015. Planting and experimental design: During Rabi - Summer of 2015, the five parental lines, twenty F1 hybrids along with susceptible line CoBhH 1(border crop) were raised in a randomized block design with two replications at the Vegetable Orchard,