Seed industry was the ‘chip’ of agricultural development, and original innovation have played essential roles in maintaining stable development of modern agriculture. The No. 1 central document of China released in 2021 has put forward requirements of original innovation researches essential for supporting further developments of Chinese crop seed industry. Foxtail millet is a traditional crop species cultivated for both forage and grain food consumption in China, and to date, foxtail millet was still widely planted as minor cereals in China with the largest scale of field production and commercial consumption across the globe. Foxtail millet was originated from China and cultivated for thousands of years to ensure development of Chinese agricultural culture and field crop production. Original innovation in foxtail millet has promoted initial development of foxtail millet seed industry based on operation of herbicide-resistant varieties in recent decades, including breakthroughs in areas of heterosis utilization, herbicide resistant breeding, dwarfing variety creation and genomics study of this important crop species. Achievements of fundamental researches including germplasm characterization, development of breeding tools, coordination and regulation of vital traits, seeds propagation and truth identification of commercial varieties have provided more opportunities for further development of the seed industry of foxtail millet. However, challenges of seed industry development still exist in China, including deficiency of excellent germplasms, backward breeding approaches, inharmonious of yield and quality characters, unclear criterion of seed propagation and market supervision problems. Future direction of original innovation studies related to foxtail millet seed industry were as follows: 1) Large scale breeding systems constructed from utilizations of crop phenomics and genomic modification technologies, double haploid breeding and genome selection tools, identification and pyramiding of superior haplotypes; 2) Seeds production, store and quality supervision systems constructed from techniques of development and water content of commercial seeds, and establishment of molecular fingerprints and efficient utilization of heterosis in foxtail millet; 3) Construction of innovation system through integrating education, research and promotion sectors of seed industry and stimulate personnel training in China.

Carotenoid biosynthesis and accumulation are important in determining nutritional and commercial value of crop products. Yellow pigmentation of mature kernels caused by carotenoids is considered a vital quality trait in foxtail millet, an ancient and widely cultivated cereal crop across the world. Genomic regions associated with yellow pigment content (YPC), lutein and zeaxanthin in foxtail millet grains were identified by genome-wide association analysis (GWAS), and SiPSY1 (Phytoene synthase 1 which regulates formation of the 40-carbon backbone of carotenoids) was confirmed as the main contributor to all three components by knockout and overexpression analysis. SiPSY1 was expressed in seedlings, leaves, panicles, and mature seeds, and was subcellularly localized to chloroplasts. Transcription of SiPSY1 in 15 DAP immature grains was responsible for YPC in mature seeds. Selection of SiPSY1 combined with increased YPC in mature grains during domestication of foxtail millet was confirmed. Haplotype analysis suggested that expression level of SiPSY1 could be a selection target for future breeding programs, and a KASP marker was developed for selection of favorable SiPSY1 alleles in breeding. The results of this work will benefit nutritional and commercial improvement of foxtail millet varieties, as well as other cereal crops.