Chapter 3 - Speed breeding—A powerful tool to breed more crops in less time accelerating crop research

Abstract

Global food security has become a major worry as the human population grows and the climate changes. The current rate of improvement of several major crops is insufficient to fulfill future demand. This slow rate of progress can be due in part to crop plants’ long generation times, which have been reduced using various methods such as shuttle breeding, doubled haploid technology, genomic selection, and speed breeding. Speed breeding is a NASA-developed technique that drastically reduces the time of generation and speeds up the research and plant breeding programs in the world. Speed breeding is a technique for shortening the breeding cycle and speeding up crop research by rapidly advancing generations. Speed breeding can be accomplished in a number of ways, including reducing generation time, increasing the period of plants’ daily light exposure, combining early harvest of seed, and cycling quickly from seed to seed (Ghosh et al., 2018). Spring wheat, durum wheat, barley, chickpea, and pea can be developed at a pace of six generations per year, compared to two to three generations under standard glasshouse conditions, while canola (Brassica napus) can be bred at four generations per year (Watson et al., 2018). In addition to reducing the generation time, breeding provides a rapid generation cycle through single-seed descent (SSD) and the opportunity for adaptation to larger-scale agricultural improvement efforts. Speed breeding can be used to investigate a variety of physiological parameters as well as optimize the transgenic pipeline, gene stacking, genomic selection, and express editing for crop development. There are some limitations to speed breeding, such as the fact that it is not suitable for short-day plants or plants that require vernalization. The given speed breeding processes take place in an artificial environment that is enclosed in specific structures that differs greatly from the fields where usually crop production may take place. Plant breeding has produced high-yielding crops that have allowed human population expansion to continue for the past 100years. In the coming decades, the development of next-generation varieties through speed breeding will meet the requirement of population expansion.