Authors: Jiankang Wang Ravi P Singh HansJoachim Braun Wolfgang H Pfeiffer
Publish Date: 2008/11/26
Volume: 118, Issue: 4, Pages: 683-694
Abstract
A strategy combining single backcrossing with selected bulk breeding has been successfully used in wheat improvement at CIMMYT to introgress rust resistant genes from donor parents to elite adapted cultivars In this research the efficiency of this breeding strategy was compared to other crossing and selection strategies through computer simulation Results indicated this breeding strategy has advantages in retaining or improving the adaptation of the recurrent parents and at the same time transferring most of the desired donor genes in a wide range of scenarios Two rounds of backcrossing have advantages when the adaptation of donor parents is much poorer than that of the adapted parents but the advantage of three rounds of backcrossing over two rounds is minimal We recommend using the single backcrossing breeding strategy SBBS when three conditions are met 1 multiple genes govern the phenotypic traits to be transferred from donor parents to adapted parents 2 the donor parents have some favorable genes that may contribute to the improvement of adaptation in the recipient parents and 3 conventional phenotypic selection is being applied or individual genotypes cannot be precisely identified We envisage that all three conditions commonly exist in modern breeding programs and therefore believe that SBBS could be applied widely However we do not exclude the use of repeated backcrossing if the transferred genes can be precisely identified by closely linked molecular markers and the donor parents have extremely poor adaptationThe authors wish to thank Dr Rodomiro Ortiz for his critical review of the manuscript before submission two anonymous reviewers and the editor for their constructive suggestions and comments on earlier versions of the manuscript This research was funded by the National 863 Programs of China grant No 2006AA10Z1B1 the HarvestPlus and Generation Challenge Programs of the Consultative Group on International Agricultural Research CGIAR and Foundation of the Institute of Crop Science Chinese Academy of Agricultural Sciences 08206030209 Development of the simulation tool QuLine was previously funded by the Grain Research and Development Corporation GRDC Australia
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