Plant breeding success or failure is directly related to cross-selection. However, data required to find promising crosses can only be obtained following integration and analysis of multiple types of breeding-related data such as phenotypic and genomic data. To promote the use of breeding data, the authors developed a breeding support system consisting of two functionalities, “variety characteristics information” and “progeny predictions,” using standard genetic analyses on typical breeding-related datasets. Users of the system can search gene haplotypes and traits of cultivars or breeding lines on the “variety characteristics information” page. As typical phenotypic data from a breeding program consist of multiple years, locations, and conditions, a linear mixed-effects model was applied to estimate breeding values (genetic abilities) of cultivars and breeding lines so that users could compare traits of all cultivars and lines even when not all are evaluated together in a single trial. In addition, the “progeny predictions” page shows genetic characteristics of crosses, such as prediction results of quantitative traits, based on genomic prediction and segregation of each locus derived from parental gene haplotypes. This enables users to find promising crosses such as those with high yields with little segregation in days to maturity. Collectively, the breeding support system provides data-driven information on strengths and weaknesses of lines and crosses. The system may facilitate selection of promising crosses by breeders based on both tacit knowledge from experience in the field and explicit knowledge obtained by genetic analyses of breeding-related data.

Recent advances in computer simulation technologies have made it increasingly possible to simulate the shapes of plant organs during their developmental processes. How may such technologies contribute to research in plant breeding science? This review introduces the fundamental concepts of a technique known as plant tissue growth modeling. In particular, we outline recent studies focusing on relative growth rates, axiality that determines growth direction, and mechanical conflicts that lead to organ deformation. Furthermore, we discuss the potential applications of this technique in the field of plant breeding studies.

We investigated bolting time using a total of 190 domestic and foreign cultivars/genetic resources of Brassica rapa at Morioka in four trials of early-spring-sown cultivation in 2021–2024. We also investigated genotypes of BrFLCs from 145–151 cultivars/lines using DNA markers. The bolting traits (flower bud appearing dates and 10 cm bolting dates) were highly correlated among trials. Distributions of late-bolting alleles of BrFLC2 and BrFLC3 found from ‘Leafy Green Parental Line No. 2’ were limited in B. rapa. In contrast, SNP allele for BrFLC1 was widely distributed in B. rapa, whereas most turnip cultivars possessed late allele. In 2022 and 2023 trials, bolting time of cultivars/lines possessing late allele (G) for BrFLC1 was significantly later than those for early allele (A) and heterozygous (H) cultivars/lines in B. rapa. Similar results were obtained from bolting time data of Chinese cabbage. The findings suggest that the G allele for BrFLC1 is widely used for the late-bolting breeding of Chinese cabbage in Japan.

While demand for rice as a staple food in Japan remains sluggish, climate change and social conditions are causing instability in rice production and supply. Against this backdrop, areas under rice cultivation are declining, and the introduction of high-yielding varieties is essential for improving productivity. Additionally, expanding rice exports is a critical challenge for the sustainable development of Japanese agriculture. The authors bred a new rice variety named ‘Shine Pearl’, which combines high yield with high eating quality, and is suitable for export purposes. In 2009, a cross was made between ‘Seinan 136’ (later named ‘Natsuhonoka’), a mid- to late-maturing, high-yield, and high-quality variety used as the mother, and ‘Etsunan 227’, an early-maturing, and high eating quality variety used as the father. ‘Shine Pearl’ was submitted for variety registration with the Seed and Seeding Division of MAFF in 2022. ‘Shine Pearl’ is classified as a mid-maturing variety in Fukui, with a culm length 22 cm shorter than ‘Koshihikari’, a thousand-grain weight 2.5 g heavier. Its brown rice yield, sieved at 1.9 mm, was 23% higher than that of ‘Koshihikari’ in standard fertilizer yield trials, and 4% higher than that of ‘Ikuhikari’ in high-fertilizer-level trials. Its protein content in brown rice and amylose content in polished rice are comparable to those of ‘Koshihikari’, and sensory test results also showed equivalent eating quality. ‘Shine Pearl’ has received high evaluations from rice dealers in Hong Kong and Singapore. While ‘Shine Pearl’ exhibits strong lodging resistance, its field resistance to blast disease is relatively weak, requiring careful cultivation. In Fukui Prefecture, approximately 880 tons of ‘Shine Pearl’ rice were produced in 2024, all of which were exported. Since rice for export can be treated as rotation crops, incorporating ‘Shine Pearl’, which can maintain paddy field functions while reducing production costs with high yields, into the crop rotation system is expected to contribute to stable farm management in the region.

Ukraine, blessed with fertile black soil and a steppe climate, has supported the world’s food supply as Europe’s leading wheat producer. Ukrainian genetic resources are also extremely important for Japanese wheat breeding. A prime example is ‘Yumechikara,’ a bread wheat developed in 2009 and currently the most widely cultivated bread-making variety in Japan. This variety was developed by crossing the US line ‘KS831957’ with Hokkaido lines ‘Satsukei 159’ and ‘Kitanokaori.’ The Ukrainian parent of ‘KS831957,’ ‘Odesskaya 51,’ contributed resistance to wheat yellow mosaic disease and excellent baking quality. Additionally, ‘Turkey Red,’ a Ukrainian variety introduced to North America in the 19th century, contributed to the development of Japan’s ‘Nōrin 10’ and major Hokkaido varieties. Ukrainian wheat breeding began in the late 19th century under Imperial Russia and produced excellent varieties like ‘Mironovskaya 808’ during the Soviet era. However, the political regimes significantly impacted development, causing research stagnation due to Lysenkoism and the tragedy of the Holodomor. Since independence, the National Academy of Agrarian Sciences has led research, continuing to develop varieties combining cold tolerance, drought resistance, and high quality. However, the war since 2022 has markedly reduced production, with research institutions also suffering damage. Amid the ongoing war and climate change, the bond in wheat breeding connecting Ukraine and Japan offers important insights for envisioning a sustainable future for food production.