For the genetic analysis of tillering behavior in the late-bolting bunching onion ‘Okunegi’, a correlation analysis was performed at first between tiller number and various traits in ten bunching onion cultivars and four breeding lines. There were no significant correlations between the tiller number and bolting time, suggesting that it is possible to select independently for tillers and late bolting. Next, 6 × 6 half-diallel analysis was performed using five bunching onion cultivars and a single breeding line with various tiller numbers and bolting times picked up by the above correlation analysis. The tiller number was counted at three growth stages. The analysis of variance for tiller number in this half-diallel table showed that the additive variance of tiller number was much larger than the dominance variance and that its average degree of dominance was less than one at all stages. This suggests that the number of tillers was an incomplete dominant trait with a large additive effect, and that the dominant genes for tiller number act to increase tillers. In addition, the tiller number of the materials at three stages and their diallel analysis showed that the dominance order and the proportion of dominant and/or recessive genes in the parental lines varied as they grew, suggesting that the type and mechanism of the genes controlling tiller number are different among the parental lines. Furthermore, the high heritability in the narrow sense (>0.78 in each growth stage) and the results of the analysis of variance also suggested that selection in the early segregating generation is very important for the breeding of a monoculm late-bolting line from ‘Okunegi’.

Oats (Avena sativa) are an important forage crop and are mainly sown in late summer in the Kyushu region of Japan, which means they are sown between late August and early September and harvested around December, ensuring forage production during the winter season. Oat varieties for late-summer sowing are required to have several adaptive traits, such as extremely early heading, crown-rust resistance, and lodging resistance, resulting in an expansion of the appropriate sowing period, producing stable foraging. A new variety for late-summer sowing, “K42R8”, was developed in the present study, which shows stable heading in December, even when sown in late September in the Kyushu region, and has enhanced crown-rust resistance. “K42R8” heads as early as one of the earliest oat varieties, “Kyushu 15”, in the appropriate sowing period and slightly later with late sowing. On the other hand, most plants of “K42R8” showed complete panicle emergence at harvest time with late sowing, as “Kyushu 15” does, and therefore it was felt that “K42R8” stably reached heading in winter even when cultivated by late sowing. Although the dry matter yield of “K42R8” in late sowing is 8% lower on a 2-location average over two years than that of “Kyushu 15”, it is considered that “K42R8” is enough to satisfy demands from forage producers because the yield of “K42R8” was equal to or greater than that of “West”, which is the most common variety in Japan. In addition, “K42R8” showed stable resistance to crown rust during late-summer-, fall-, and spring-sown cultivation in the field. It is expected that “K42R8” can be utilized in warm regions of Japan, from Kanto to southern Kyushu, contributing to stable forage production through risk reduction against bad weather and task distribution by expanding the appropriate sowing period. The present study also demonstrated that “K42R8” showed greater crown-rust resistance, and thus it is hoped that “K42R8” may become widespread as a novel crown-rust resistant variety in oat cultivation.

In Japanese rice farming, rice cultivars that can achieve stable sales at high prices while reducing production costs and the environmental footprint are required. Currently, there are only a few early maturing cultivars that can meet the requirements of rice farmers by combining high-temperature grain-ripening ability and disease resistance. ‘Natsuiro’ was bred by rapidly introducing pi21, a rice blast resistance gene derived from ‘Tomohonami’, into the ‘Mie 23’ genetic background, an early maturing rice cultivar with high-temperature grain-ripening ability. In the continuous backcrossing, in each generation from BC₁F₁ to BC₃F₁, DNA marker-assisted selection of pi21, in addition to genome-wide marker-based background selection, achieved the desired genotypes in 2 years and 2 months after the first artificial crossings in 2013. After that, after line selection and characterization studies such as productivity tests, an application for cultivar registration was filed six years later in 2019. Compared to ‘Mie 23’, ‘Natsuiro’ has mostly the same agronomic traits except for stronger blast-resistance, slightly longer culm length and panicle length, slightly shorter grain length and slightly smaller 1000-grain weight. The culm length of ‘Natsuiro’ is 10 cm shorter than that of ‘Koshihikari’, and the number of ears is slightly less, resulting in an “intermediate” grass type. The heading dates and maturity dates are 3 and 5 days earlier than those of ‘Koshihikari’, respectively. This cultivar has “very strong” leaf blast resistance enhanced by pi21. The high-temperature grain-ripening ability is the same as that of ‘Mie 23’ and higher than that of ‘Koshihikari’, and the class is “strong”. ‘Natsuiro’ was adopted as a recommended cultivar of Mie Prefecture in 2020. It is expected to be widely distributed as an early maturing cultivar that can meet the requirements of rice farmers by combining high-temperature grain-ripening ability and disease resistance.

Dietary fiber is a component with many physiological functions, but in recent years, the average dietary fiber intake of Japanese people has been below the target amount. From a fixed mutant group of ‘WPK’, which is a white panicle mutant of ‘Koshihikari’, treated with 0.1 M EMS (ethyl methane sulfonate), ‘WFE5’ was selected for its high dietary fiber content in the polished rice with a chalky appearance of brown rice. A cross was made between ‘WFE5’ and ‘Koshihikari’, and by backcrossing with ‘Koshihikari’ to the resulted F₃ plant, ‘Koshihikari NIL [WFE5]’ was bred as a near-isogenic line of ‘Koshihikari’ for high dietary fiber. We evaluated the dietary fiber content, cultivation characteristics, and eating quality of ‘Koshihikari NIL [WFE5]’ for several years. As a result, ‘Koshihikari NIL [WFE5]’ was found to contain about three times as much dietary fiber as ‘Koshihikari’ in the polished rice, and its taste was determined to be comparable to that of ‘Nipponbare’. Therefore, Fukui Agricultural Experiment Station, Niigata University, and National Agriculture and Food Research Organization (NARO) jointly applied for the registration as ‘Shinfuku 1’ in the belief that the dietary fiber intake from the polished rice can contribute to improving the health of Japanese people. The dietary fiber content of ‘Shinfuku 1’ was 5.1 and 2.6% for the brown and polished rice, respectively, as a five-year average. The dietary fiber content varied from year to year, with larger grain weights tending to have a higher dietary fiber content. The cultivation characteristics of ‘Shinfuku 1’ were almost the same as those of ‘Koshihikari’, but its yield was 68% of ‘Koshihikari’. The brown rice of ‘Shinfuku 1’ was chalky and its thousand-grain weight about 15.5% less than that of ‘Koshihikari’, its resistance to lodging was slightly stronger than that of ‘Koshihikari’, and its pre-harvest sprouting was slightly easier than that of ‘Koshihikari’.

Smart breeding based on big data is expected to accelerate crop breeding to meet various problems posed by climate change and so on. The Ministry of Agriculture, Forestry, and Fisheries (MAFF) started the project for smart breeding (“Smart-breeding system for Innovative Agriculture”, as part of the “Next Generation Breeding and Health Promotion Project” (2019–2023)). In this workshop, we presented an overview of the two research themes in this project: “Development of big data database and advanced supporting system in crop breeding (BAC)” and “Development of Innovative breeding Technology (DIT)”. We also gave a PC demonstration of three breeding tools: “BRIMASS”, a breeding information management support system that allows users to efficiently share the large-scale crop phenotype and genotype data on the internet; “Pedigree Finder”, a graph database of genealogical information that displays information on breeding pedigrees, enables effective use of pedigree data for breeding and crop data analysis; and “AlleleGraph”, a tool that allows visualization of allele combinations of agronomically important loci and trait information for many cultivars.