What's happening at IRRI
Wednesday, March 22, 2017, 02:00pm - 03:00pm
Title: Selecting crops with greater water productivity - integrating genetics and
phenotyping in delivery of vigorous wheat breeding lines
Crops reliant on rainfall for growth commonly experience water deficit to reduce grain yield and quality. This challenge is acknowledged with breeders selecting for genotypic adaptation to water-limited environments. However, progress is slow, many factors contributing to slowing breeding progress in rainfed environments: (1) strict requirements for improved grain quality and disease resistance reduce genetic variance for performance under drought; (2) drought is a dynamic entity changing in timing and severity from one year/site to the next; and (3) both the above contributing to large genotype × environment interaction to reduce repeatability of genotype performance and confidence in selection. The opportunity exists to compliment existing selection for yield with novel trait variation to improve performance.
Side-by-side comparisons of wheat with barley and triticale show wheat consistently produces smaller yields owing to its lower water-use efficiency. Barley and triticale produce greater leaf area and biomass early in the season to shade the soil surface, in turn, increasing transpiration efficiency and reducing water loss through soil evaporation. Wheat is inherently conservative in its early growth. Efforts to source global diversity for ‘early vigour’ alleles using S1 recurrent selection, and linked markers for new gibberellin-sensitive dwarfing genes has delivered elite germplasm with greater biomass and yield, and unexpected benefits in improved competitiveness with weeds and greater nutrient uptake. These lines are now being delivered for use in commercial breeding.
Dr. Greg Rebetzke
Group Leader - Southern Crops,
Breeding High Value Food Crops,
Agriculture and Food,
Commonwealth Scientific and Research Organization
Rm A, DL Umali Bldg.