Marker-assisted pyramiding of transgenic resistance to bacterial blight and tungro in popular rice cultivars
2008
Godoy, J.G. | Pastor, H. | Tabanao, D., Philippine Rice Research Inst., Maligaya, Science City of Munoz, Nueva Ecija (Philippines). Central Experiment Station
Bacterial blight (BB) and tungro remains the most destructive rice diseases in the Philippines. Modern tools such as marker-assisted selection (MAS) and transformation can be effectively used to speed-up the development of built-in resistance to these diseases. The objective of this study was to combine resistance genes to bacterial blight (BB) and tungro from transgenic materials into IR64, PSB Rc28 and PSB Rc82. Transgenic TP309, carrying the RTSV Replicase gene, was crossed to a genetically engineered IR72, carrying the clone Xa21 gene. The F1 was three-way crossed to popular varieties, IR64, PSB Rc28 and PSB Rc82, followed by two cycles of backcrossing, which involved MAS for resistance genes. Xa21 was assayed using the primer pair U1 and I1 whereas Rep was assayed using primers designed by ILTAB. Selected BC2F2 lines that had both REP and Xa21 were thereafter maintained for each recurrent parent. Using phenotypic assay and MAS, 93 BC2F4 promising lines that were positive for both Rep and Xa21 were selected and planted in 2008 DS. The best families that will be selected among these lines will undergo a third cycle of backcrossing. Individual plant selection with molecular assay and phenotypic screening will be done in the BC3F1 and BC3F2. Family selection based on phenotypic and genotypic data will be made in the BC3F3. Promising BC3F4 lines will be grown in a confined field test at PhilRice CES.
显示更多 [+] 显示较少 [-]