Hexaploid wheat (Triticum aestivum) has undergone two hybridization events resulting in severe genetic bottlenecks, particularly in the D genome contributed by the diploid progenitor species, Aegilops tauschii. One method to regain this genetic diversity is through interspecific hybrids with diploid progenitors. This requires embryo rescues to recover progeny due to endosperm failure of the hybrids. Previous studies in Arabidopsis and rice have demonstrated that mutations in imprinted Polycomb Repressive Complex 2 (PRC2) genes medea (MEA), fertilization independent endosperm (FIE), and fertilization independent seed 2 (FIS2) can, or potentially can, restore endosperm function to interploidy hybrids. Homologs of MEA, FIE, and FIS2 were identified in the wheat A, B and D genomes. Pyramids of double and triple mutants were developed using a combination of Kompetative allele specific PCR (KASP) markers and amplicon sequencing. Single, double, and triple mutants at MEA, FIE, and FIS2 associated with the three subgenomes were hybridized with Ae. tauschii to identify mutant combinations that may restore endosperm function.The wheat breeding program at Michigan State University utilizes a modified bulk breeding method to rapidly advance populations from the F2 to F4 stage under greenhouse conditions. To determine the influence of planting density on yield components and plant architecture in greenhouse settings, two experiments were carried out using two spring and winter wheat. Experiments with both spring and winter wheat demonstrated that increased planting density reduces plant height, spikelets per spike, grain length and grain width.
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