Breeding crops by design for future agriculture

摘要

Plant breeding is both the science and art of de-veloping elite crop cultivars by creating and reas-sembling desirable inherited traits for human benefit.From the bulk selection of wild plants for cultivationduring early civilization to Mendelian genetics andgenomics-assisted breeding in modern society, breedingmethodologies have evolved over the last thousandyears. In the past few decades, the “Green Revolution”through breeding of semi-dwarf wheat and rice vari-eties, and the use of heterosis and transgenic cropshave dramatically enhanced crop productivity andhelped prevent widespread famine (Hickey et al.,2019). Integration of these technologies can signifi-cantly improve breeding efficiency in the develop-ment of super crop varieties (Li et al., 2018). Forexample, a hybrid cotton variety CCRI63 and sixrelated hybrid varieties account for nearly 90% ofcotton production in the Yangtze River Basin (Wanet al., 2017; Wang et al., 2018). These varieties havesuccessfully combined high yield, good quality, andbiotic stress tolerance through the integration ofconventional breeding, hybrid and genetically modi-fied organism (GMO) technologies (Lu et al., 2019;Ma et al., 2019; Song et al., 2019). Unfortunately,such technology integration is not practical for moststaple food crops, including rice and wheat, becauseof social or technical restrictions. Furthermore, plantbreeding is still labor-intensive and time-consuming,and conventional breeding remains the leading ap-proach for the release of commercial crop varietiesworldwide. This is especially true for breeding cul-tivars and hybrids with high yield, good quality, andresistance to biotic or abiotic stresses (Liu et al., 2015;Gu et al., 2016). New germplasm, knowledge, andbreeding techniques are required to breed the nextgeneration of crop varieties.