Thesis: Genetic Analysis of Seed Dormancy for Pre-harvest Sprouting Resistance in Wheat
PHS refers to the phenomenon where seeds germinate or sprout on the plant when the un-harvested grain encounter rain or an air-humidity close to saturation. PHS is a quantitative trait regulated by several genes or QTLs and affected by environmental factors. Research on seed dormancy using QTL analysis has identified a number of loci, and the 4AL QTL is a major QTL and is consistently identified in different research. However, the specific 4AL gene(s) responsible for PHS resistance has not been identified so far. My research will focus on the following areas:
• Developing near-isogenic lines (NILs) for the 4AL PHS resistance locus.
• Using reported markers that are linked to other major QTLs for PHS resistance to screen Australian wheat varieties with known PHS phenotyping data of the National Variety Trial (NVT).
• Diallel analysis using a full diallel of four genotypes to get a comprehensive understanding of the genetics of PHS variation.
Why my research is important
Pre-harvest sprouting (PHS) can cause severe damage to wheat yield, nutritional quality, processing quality (especially the starch quality of flour) and seed value of the crop, and it is a worldwide issue. Although research on seed dormancy using QTL analysis has identified a number of loci, especially on 4AL, the specific 4AL gene(s) responsible for PHS resistance has not been identified so far. My research will focus on QTLs on 4AL. By incorporating the fast generation technique, at least 10NIL pairs showing consistent marker-gene linkage and segregating for the major QTL will be developed by the end of this project. Transcriptome analysis on these NILs will be able to identify the major 4AL gene responsible for PHS resistance.