Herbicide resistance in Setaria

SPEGESTADCT2 INRAHerbicide resistance in Setari

Setaria

International audienceFoxtail millet, Setaria italica (L.) Beauv., is the only Setaria grown as crop. It is a small grain cereal of the Paniceae tribe. It has long been important for human consumption in China and India where it was domesticated more than 8,000 years ago. It is also grown in small quantities throughout Eurasia for some traditional uses and for feeding birds, and in Europe and America for hay and silage. The chapter describes the taxonomy, the biology, and the role in crop breeding of the few wild relatives pertaining to its gene pool complex, all known as noxious weeds. They include its putative wild ancestor, S. viridis (green foxtail), which forms the primary gene pool at a diploid level of genome A and comprises the progeny of the spontaneous hybrids between the two taxa, S. viridis ssp. pycnocoma. The secondary gene pool includes the diploid of genome B, S. adhaerans (bristly grass), and the allotetraploid AB species S. verticillata (bristly foxtail) and S. faberi (giant foxtail). This small number of wild related species was in fact seldom used for foxtail millet genetic improvement, except only in a few cases of research for male sterility and herbicide resistance. The reason for such little impetus could be due to the structure of the wild–weed–crop primary gene pool, which provided enough genetic diversity through “off-types” and the selection of many diverse landraces. In addition, their success as weeds as the consequence of intentional and unintentional weed management for over 10,000 years perhaps reduced the field of selectable beneficial traits. In contrast, wild Setaria were invaluable resources to gain better knowledge of the genome organization of the crop. Besides phylogeny, cytogenetics, genetic attributes and mating system, phenotypic variation, distribution and population genetics of the wild species as well as interspecific breeding methods are documente