Breeding Science Special Issue: Soybean breeding in genomic era

Soybean is one of the world’s most important crops, offering a stable source of materials for food, feed, industrial, and pharmaceutical applications. Soybean seeds contain a high content of nutritious protein and oil, and assume an important part of traditional foods in many Asian countries, including Japan. They are also abundant in physiologically active metabolites and functional proteins, and are used as an affordable source of foods that promote and maintain health. Soybean also contributes to soil fertility through nitrogen fixation via symbiotic root bacteroids. Indeed, soybean production has increased the most of all major crops in response to recent increases in global demand for produce. The genomic era is now arriving in soybean, as in other many crops. The release of a genome assembly of the US cultivar ‘Williams 82’ from the US Department of Energy (DOE) Joint Genome Institute (JGI) in 2008 and its publication in 2010 has had a great impact on the understanding of gene function and breeding of soybean. In Japan, a soybean genome project was launched in 2007 with the financial support of the Ministry of Agriculture, Forestry and Fisheries (MAFF) through its Genomics for Agricultural Innovation. The project consists of three parts: (1) the construction of linkage and physical maps of soybean, and genome sequencing of the Japanese cultivar ‘Enrei’; (2) the identification of genes responsible for agriculturally important traits; and (3) the development of DNA markers for important traits and for the breeding of new lines. Target traits include flood tolerance, disease and pest resistance, and physiological and morphological characters related to productivity. The third part of the project was expanded in a new MAFF project (Development of Mitigation and Adaptation Techniques for to Global Warming in the Sectors of Agriculture, Forestry, and Fisheries) from 2011. In addition, the National BioResource Project (NBRP) Lotus and Glycine, promoted by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), has supported the development of soybean genomic research through the collection, conservation, and distribution of bioresources such as experimental strains, mutants, and cDNA libraries since 2003. All of these activities will boost soybean breeding and science into a new stage in the genomic era. Taking this opportunity, the editorial board of the Japanese Society of Breeding (JSB) decided to dedicate this special issue of Breeding Science to recent domestic and international advances in soybean genetics, genomics, and breeding. The contents comprise several reviews of the extensive knowledge of genomic and genetic resources, key technologies, and agriculturally important traits for understanding gene function and soybean improvement. Original research articles support the key concepts of the review articles. Through this special issue, the editorial board members and the participants hope to contribute to and facilitate further successful improvement of this valuable crop. Members of JSB and several non-member authors willingly accepted an invitation to contribute to this special issue. All the manuscripts were peer-reviewed by a number of local and international scientists. We take this opportunity to thank our colleagues J. Abe, S. Akada, H. Akamatsu, S.B. Cannon, H. Funatsuki, M. Hajika, T. Han, Y. HayanoSaito, M. Hayashi, A. Kaga, A. Kanazawa, H. Kato, K. Komatsu, Y. Kuroda, B. Liu, K. Naito, K. Nishizawa, S. Sakai, S. Sato, T. Sayama, M. Senda, J. Smith, P. Somta, A. Suzuki, N. Tomooka, D. Vaughan, Y. Wang, S. Watanabe, D. Xu, T. Yamada, N. Yamagishi, N. Yamanaka, H. Yasui, T. Yokoyama for their participation in the review process. Their constructive comments have been invaluable in improving the quality of the articles. Thirteen review papers, ten research papers, and one short communication were accepted for publication. The editors working on the special issue were J. Abe, T. Anai, D. Vaughan, D. Xu, and M. Ishimoto, and the technical editors were N. Tomooka and F. Taguchi-Shiobara. In closing, we would like to acknowledge the two research projects promoted by MAFF, as well as the NBRP Lotus and Glycine promoted by MEXT, for sponsoring this special issue of Breeding Science.