As a consequence of extreme changes in climate, farming scale, and social structure, the requirements for rice yield potential and grain quality have been changing in Japan. To meet the demands of consumers, rice processing companies, and paddy farmers, “Tsukiakari” and “Niji-no-kirameki” were developed as high-yielding and highly palatable rice cultivars. The palatability of both cultivars is excellent and is as high as the leading Japanese cultivar, “Koshihikari.” The yield potential of the new cultivars is over 700 g m⁻² (brown rice, 15% moisture basis), and their shorter culm lengths provide greater lodging tolerance. “Tsukiakari” has been mainly distributed in the northern and central regions of Honshu, whereas “Niji-no-kirameki” has been distributed in the central and western regions. An early maturity cultivar, “Tsukiakari,” is useful for separating harvest schedule from “Koshihikari.” “Niji-no-kirameki” has been replacing “Koshihikari” in heat-vulnerable regions due to its superior heat resilience during the ripening period. Establishing proper cultivation methods for “Tsukiakari” and “Niji-no-kirameki” through multiple environmental tests helps local farmers efficiently manage their farms and produce high-yielding and highly palatable crops. Superior characteristics of “Tsukiakari” and “Niji-no-kirameki” will be useful to develop new rice genotypes that highly meet the needs of the times.

Citrus species grown in Japan are affected by three major viruses: satsuma dwarf virus (SDV), citrus tatter leaf virus (CTLV, apple stem grooving virus), and citrus tristeza virus (CTV). SDV has spread to other countries, such as China, Korea, and Turkey, apparently through unchecked budwoods and nursery trees; it is natural to assume that some of these contaminated plants harbored CTLV and CTV as well. Thus, citrus viruses in Japan are not only a domestic problem, they are also transboundary threats to agricultural production. This article reviews the occurrence and history of SDV, CTLV, and CTV in Japan as well as recent research developments in Japan and other countries.

Mycoplasma bovis and M. californicum cause a variety of bovine diseases. Spread of these mycoplasmas is difficult to control because it occurs predominantly through asymptomatically infected individuals according to the results of molecular epidemiological analyses. After the 2000s, M. bovis strains having low susceptibility to 16-membered macrolides and tetracyclines have spread in Japan. With the spread of these low-susceptibility M. bovis strains seeming to be involved in the refractoriness to antimicrobial therapy often found in cases of M. bovis infection, it is speculated that these M. bovis strains entered Japan through the importation of bovine biological resources, such as breeding dairy cows, semen, and fertilized eggs. Additionally, appearance of M. bovis strains having low susceptibility to fluoroquinolone is suggested to have relevance to the increase of the amount of fluoroquinolone purchased, being as it is a frequent characteristic of beef cattle-derived strains. The identification of mutations involved in antimicrobial susceptibility and the development of methods to directly detect such mutations have significantly reduced the time required to understand a causal strain’s antimicrobial susceptibility. Selection of antimicrobial agents by this method is expected not only to improve the cure rate but also to greatly contribute to the reduction of antibiotic usage.

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), is an economically important polyphagous pest, which has recently expanded its distribution from the Americas to over 70 countries. Here, we established an efficient rearing method for S. frugiperda under crowded conditions. First, we clarified the larval density at which there is no decrease in survival rate due to cannibalism. Spodoptera frugiperda larvae were maintained on an artificial diet till pupation under five density conditions: 10, 30, 50, 70, and 100 individuals per container (5.4L, 26.8 cm × 20.7 cm × 9.8 cm). Survival rates at adult emergence were approximately 70% at density conditions of less than 50, and those in the container with paper towels as refuge were higher than those in the container without paper towels. In the second experiment, two individuals at different developmental stages from 5th instar to pupa were released in a container with or without food, and with or without paper towels, to clarify the developmental stages at which cannibalism occurs. Even when food was present, the individuals without access to refuge during the prepupa were attacked by the 6th instar larva. Our results suggested that conditions which include refuge and moderate density facilitate the rearing of S. frugiperda larvae under crowded conditions.

By modifying a previous simple rapid method, we propose an in-situ simple, rapid calibration method based on soil porosity and the highest raw sensor output (RAW) obtained after heavy rainfall during the monitoring period. According to the results of our verifying experiments for three soils, we concluded that the modified method is applicable to monitoring results, including previously obtained uncalibrated data, that satisfy three criteria: (1) the monitoring data must include at least a few peak RAW values of around 1,200-1,300, (2) the monitoring data must capture changes in the water content at appropriate intervals, and (3) it must be possible to estimate the soil porosity of the soil at the monitoring site.

General flowering (GF) is a synchronous flowering phenomenon in the Southeast Asian tropical rainforests that occurs at irregular intervals of multiple years. While in this study, the leaf transcriptome of a GF species, Shorea curtisii obtained from three-time points – before and after floral initiation, and post-flowering stage – was sequenced, the unpredictable intervals of GF raise conservation concerns for these under-researched forests with rich economically and ecologically important species. We assembled 243,759,478 sequencing reads into 39,943 non-redundant unigenes including 677 putative homologs of Arabidopsis thaliana flowering-related genes. Differential expression analysis conducted on pairwise comparisons of the time points identified 930 differentially expressed unigenes, which includes 17 flowering-related homologs. The differential expression of unigenes with significant enrichments of functions related to drought corroborated the involvement of drought as an environmental cue for GF, with the outcomes of this study offering an insight into the conservation of floral regulatory genes and pathways in Shorea and possibly being used as a model to better understand the floral initiation cues and regulation of GF trees.

The neon flying squid, Ommastrephes bartramii, is an economically important oceanic squid species that has been harvested commercially in the North Pacific by Japan, Korea, China, and Taiwan. The Fisheries Research Agency (FRA) of Japan conducted long-term research for this species from 1980 to 2009 using commercial vessels to clarify the resource ecology and it obtained a total dataset of approximately 9,000 days, where following from this and to better clarify the relationship between habitat preference and oceanographic conditions, a generalized additive model was applied and mapped onto the Simple Ocean Data Assimilation ocean/sea ice reanalysis (SODA) data. The resultant habitat map of the squid showed an area of high abundance at the Subarctic Frontal Zone (SAFZ), with abundance areas increasing the squid abundance from April to August. The SAFZ extends from 40°N to 43°N separating the cold, low-salinity, subarctic water to the north from the waters of the North Pacific Transition Zone to the south. This high abundance area intersects between subarctic area and temperate area. It has characteristic nutrient regimes, productivity cycles, and nektonic faunal compositions. This paper suggests that the SAFZ thus plays an important role in North Pacific ecosystems by providing an optimal balance between environmental temperature and food density for the neon flying squid.

The preferred habitats of the round scad Decapterus maruadsi and five other scads (amberstripe scad D. muroadsi, mackerel scad D. macarellus, red scad D. akaadsi, roughear scad D. tabl, and shortfin scad D. macrosoma) in the East China Sea (ECS) and the Sea of Japan were examined based on catch records of Japanese large- and medium-type purse seine fisheries from 1993 to 2020. Delta-lognormal generalized additive models indicated that the habitats of the round scad and the other five scads were clearly segregated. A high round scad catch per unit effort (CPUE) was observed in the southwestern ECS on the continental shelf and coastal waters around Kyusyu, whereas for the other five scads, a high CPUE was observed around the shelf break and Kuroshio area. The standardized annual CPUEs of the scads decreased after 2010. Based on the proportion of round scad to all six scads calculated by spatial standardized CPUEs for each fishery grid, the total catch amount of round and the other five scads including coastal fisheries was approximately 2,071-13,382 tons and 3,496-24,617 tons, respectively. These estimates are important for scad stock assessment and developing effective management strategies.

Long-term and short-term growth performance indices (sharpness index adjusted for size dependency, SI_adj and estimated condition factor, CF, respectively) were applied to the blood cockle, Tegillarca granosa collected from four localities (Bukit Kecil Village, Penang; Kuala Sepetang, Perak; Buloh River, Selangor; and Teluk Kumbar, Penang) along the west coast of Malaysia to compare the environmental quality of the culture grounds of the blood cockle. We observed spatio-temporal patterns of the two indices and found that CF negatively correlated with SI_adj, indicating that an elongate-shaped cockle had a large mass of soft tissue where the seasonal trend of these two indices matched the maturation and spawning cycles in Bukit Kecil Village, where cockles showed good growth, and the difference in the correlation slopes exhibited suitability of local variations for cockle culture. With a wide variation range, CF negatively correlated with sediment’s oxidation-reduction potential (ORP), suggesting that the dietary benefit from eutrophication overcame the risk of sub-lethal hypoxia.

The growth and reproductive cycle of the jack mackerel (Trachurus japonicus) that were caught in the southwestern Sea of Japan during 2016-2017 were examined based on otolith annuli and gonad histology. Translucent and opaque zones on transverse sections on otoliths were identified and opaque rings were counted. The von Bertalanffy growth curve was expressed as follows: FL_t = 445{1 − exp (−0.149 (t + 1.74))} (0.250 < t < 7.67), where FL_t is the fork length (mm) at age t. The estimated body length at age t in the growth model was smaller than that of jack mackerel in the East China Sea. The spawning period was evaluated from May to September based on the monthly changes in the gonadosomatic index and histological observations. The spawning period starts later than in the East China Sea, but the minimum size at first maturity was similar to that of the jack mackerel in the East China Sea. The information generated in this research can contribute to the sustainable management of the species in the Sea of Japan.