CULTIVAR DEVELOPMENT: ACCELERATED INTROGRESSION OF SYNTHETIC HEXAPLOID DERIVED DIVERSITY INTO AN APPLIED HARD WINTER WHEAT BREEDING PROGRAM

In the USA, over 12 million acres of hard red spring (HRS) wheat are annually planted in Northern Great Plains with a production of about 500 million bushels. Developing new cultivars with higher grain yield is the major goal in HRS wheat breeding programs, which can benefit the local growers the most. Improvement of grain yield has been relying on phenotypic selection, where the long breeding cycle and low selection intensity restrict its improvement. Moreover, negative correlation between grain yield and some end-use quality traits like protein content is commonly observed in HRS wheat breeding populations, and further hampers the improvement of grain yield given the fact that maintaining suitable end-use quality is a prerequisite. Recurrent index selection is a way to improve multiple traits simultaneously and more rapidly. Genomic selection (GS) is a marker-aided selection method that can accelerate genetic gain of a complex trait by shortening breeding cycles and/or increasing selection intensity/accuracy. However, few experimental studies have been conducted on using GS index in recurrent selection, namely recurrent genomics-index selection, for multiple traits especially for negatively correlated traits. This project will serve as a pioneer for using genomics-index of multiple traits in recurrent selection, and provide breeders a complementary approach to improve grain yield in hard red spring wheat. The resulted populations will be valuable for genetic investigation of grain yield, protein content, and their interaction in wheat. The success of this project can be of broader interest to the plant breeding and genetics community.The specific objectives of this project are to:Test whether recurrent index selection can improve grain yield while maintaining protein content;Develop and validate genomic prediction models for the indices of grain yield and protein content in a synthetic population of heterozygous wheat genotypes.