QTL Analysis and Molecular Breeding for Seed Dormancy and Pre-harvest Sprouting Tolerance in Bread Wheat

摘要

In wheat, seed dormancy (SD) and pre-harvest sprouting (PHS) are two important complex physiological traits. PHS caused due to early break of seed dormancy is one of the major problems leading to degradation of grain quality and significant losses inyield. Association of PHST with red grain colour (GC) has low acceptability among consumers. Therefore, one of the major objectives in wheat breeding is the development of PHS-tolerant wheat varieties with amber grain colour. A number of QTLs have already been mapped for PHST, SD and GC on all the 21 wheat chromosomes through QTL interval mapping. This facilitated marker-assisted selection (MAS) for the improvement of PHST. Breeding approaches that are likely to be employed in future include associationmapping (AM), advanced backcross (AB)-QTL analysis, mapping-as-you-go (MAYG), marker-assisted recurrent selection (MARS) and genome-wide selection (GWS). The progress made in all aspects of the marker-trait associations (MTAs) and marker-assisted selection for PHST/SD/GC and the emerging future breeding technologies have been reviewed in this article.