female parts, and normally self-pollinate. Commercial hybrid wheat seed has been produced using chemical hybridizing agents, plant growth regulators that selectively interfere with pollen development, or naturally occurring cytoplasmic male sterility systems. Hybrid wheat has been a limited commercial success in Europe (particularly France), the United States and South Africa. Synthetic hexaploids made by crossing the wild goatgrass wheat ancestor Aegilops tauschii, and various other Aegilops, and various durum wheats are now being deployed, and these increase the genetic diversity of cultivated wheats. Triticale: Wheat-rye hybrid In ancient times, wheat was often considered a luxury grain because it had lower yield but better taste and digestibility than competitors like rye. In the 19th century, efforts were made to hybridize the two to get a crop with the best traits of both. This produced triticale, a grain with high potential, but fraught with problems relating to fertility and germination. These have mostly been solved, so that in the 20th century millions of acres of triticale are being grown worldwide. Gluten Modern bread wheat varieties have been cross-bred to contain greater amounts of gluten, which affords significant advantages for improving the quality of breads and pastas from a functional point of view. However, a 2020 study that grew and analyzed 60 wheat cultivars from between 1891 and 2010 found no changes in albumin/globulin and gluten contents over time. "Overall, the harvest year had a more significant effect on protein composition than the cultivar. At the protein level, we found no evidence to support an increased immunostimulatory potential of modern winter wheat." Water efficiency Stomata (or leaf pores) are involved in both uptake of carbon dioxide gas from the atmosphere and water vapor losses from the leaf due to water transpiration. Basic physiological investigation of these gas exchange processes has yielded valuable carbon isotope based methods that are used for breeding wheat varieties with improved water-use efficiency. These varieties can improve crop productivity in rain-fed dry-land wheat farms. Insect resistance The gene Sm1 protects against the orange wheat blossom midge. Genome In 2010, a team of UK scientists funded by BBSRC announced they had decoded the wheat genome for the first time (95% of the genome of a variety of wheat known as Chinese Spring line 42). This genome was released in a basic format for scientists and plant breeders to use but was not a fully annotated sequence which was reported in