Application of advanced backcross quantitative trait locus (QTL) analysis in crop improvement

Abstract

Domestication of crops is widely believed to be accompanied by a bottleneck that greatly reduces genetic diversity. This narrowing of genetic diversity restricts crop plant improvement by limiting the range of valuable traits available for use in modern plant breeding. Wild species are a broad resource to widen the germplasm and improve the traits in crop cultivars. However, genetic variation between species is often related to reproductive isolation or to adaptation to different natural environments and many introgressed genes prove difficult, if not impossible, to use in crop improvement. Advanced Backcross QTL (AB-QTL) analysis is an efficient method to utilize wild species by simultaneous discovery and transfer of valuable QTLs from unadapted germplasm into elite breeding lines. A number of its application in crop genetics and breeding are reviewed in this paper.