Field evaluation of germplasm lines of extra-long staple cotton (Gossypium barbadense) for Tobacco Streak Virus (TSV) resistance based on symptoms expression

Background The necrosis disease caused by Tobacco streak virus (TSV) is highly destructive. Conventional management practices for TSV includes cultural methods such as crop rotation, maintaining field sanitation, rouging of infected plants, intercropping with non-host crops of short duration, eliminating weed hosts like Parthenium and insecticide application to control vectors. However, the most efficient and convenient approach to combat this devastating disease is to cultivate resistant varieties. Results TSV distribution in the germplasm of ELS cotton, Gossypium barbadense , appears to be significant. In a consecutive two-season screening at ICAR-Central Institute for Cotton Research (CICR), Regional Station, Coimbatore, total of three hundred G. barbadense germplasm lines were evaluated for natural occurrence of TSV. Among them, fourteen germplasm lines were categorized as Resistant (R), twenty-two as Moderately Resistant (MR), one hundred and sixty-eight as Moderately Susceptible (MS), and ninety-four as Susceptible (S) lines. Conclusion The identified fourteen resistant germplasm lines of G. barbadense can be valuable resources in breeding programs as donor parents to develop TSV-resistant lines. Utilizing these lines in breeding efforts can contribute to the development of resistant varieties against TSV.