Genetic Variations for Spike Fertility and Associated Traits in US Southeastern Soft Wheat Germplasm.

The genetic progress of grain yield in wheat ranged from 0.3% to 1.0% per year during the last century, but has to be doubled to meet food needs of the 9.6 billion people expected in 2050. The progress in yield improvement of wheat is mainly attributed to better partitioning of photosynthetic products. Thus, a clear relationship between yield improvement and grain number was frequently reported. An appropriate avenue to meet the challenge of improve yield in wheat is by developing genotypes with higher spike fertility and grain number, or increased sink strength. The objective of the study was to evaluate genetic variations for spike fertility and its association with harvest index, grain number, and yield and yield contributing traits in a 300 genotype soft wheat panel. The panel was characterized for different physiological and yield contributing traits like spike fertility, grain weight, harvest index, chlorophyll content, normalized difference vegetation index (NDVI) and canopy temperature (CT). Our preliminary data depicted significant differences for spike fertility, grain weight, and harvest index, chlorophyll content (SPAD), CT and NDVI. Our research will identify loci associated with spike fertility related traits in soft wheat. The final results will help us to identify genotypes with higher partitioning and grain number which will be a valuable source for future genetic improvement of grain yield.