Screening of Abelmoschus species for resistance against yellow vein mosaic disease and root-knot nematode for the development of interspecific F1 hybrids

Thakur, Yukta

Screening of Abelmoschus species for resistance against yellow vein mosaic disease and root-knot nematode for the development of interspecific F1 hybrids

Date

2023

Authors

Thakur, Yukta

Publisher

Punjab Agricultural University

Abstract

The current study was conducted for evaluation of okra wild species against resistance/tolerance to YVMV disease, root knot nematode, and development of interspecific F1 hybrids with resistant donor parents. Further, parents and their interspecific F1 hybrids were morphologically and biochemically characterized. Sixty-five accessions of Abelmoschus moschatus and seven cultivars of Abelmoschus esculentus were subjected to artificial screening for yellow vein mosaic disease (YVMD) and root-knot nematode resistance. Sequencing of initial source plant (Pusa Sawani) exhibiting YVMD symptoms showed the presence of begomovirus okra enation leaf curl virus (OELCuV). The artificial screening identified twelve highly resistant A. moschatus accessions for YVMV disease, which were later found to be symptomless carriers of the virus upon validation with begomovirus-specific primers (DengF/DengR and OY2395F/OY680R). Five A. moschatus accessions exhibited moderate resistance to root-knot nematodes. Interspecific hybridization between YVMV-susceptible okra cultivars and YVMV-resistant A. moschatus accessions resulted in the development of three interspecific F1 hybrids (Punjab Padmini x EC316073, Pusa Sawani x EC316073 and Punjab Padmini x EC329390). Their hybridity was confirmed using SSR primer Okra037, and these hybrids remained free from YVMD symptom after 90 days of artificial screening, indicating dominant gene control of resistance. Seeds obtained from four interspecific hybrids between root-knot nematode-susceptible and root-knot nematode-resistant parents failed to germinate, indicating lack of compatibility between the parents. Both YVMD and root-knot nematode resistant genotypes depicted elevated levels of phenylalanine ammonia-lyase (PAL), tyrosine ammonia lyase (TAL), peroxidase (POD), and phenolic compounds as compared to susceptible ones and significant negative correlation with disease severity (%) and number of galls per root. This suggests that higher levels of these parameters are associated with resistance to both pests.

Citation

Thakur, Yukta (2023). Screening of Abelmoschus species for resistance against yellow vein mosaic disease and root-knot nematode for the development of interspecific F1 hybrids (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.