Molecular phylogeny and diversity of Myanmar and Bhutan mithun based on mtDNA sequences

The mithun (Bos frontalis), synonymous with mithan and gayal, is considered to be a domesticated form of gaur (B. gaurus). However, there has been a controversy concerning its origin. In an effort to address this issue, the mitochondrial cytochrome b (cytb) genes of 20 mithun from Myanmar and 13 from Bhutan were sequenced to trace its maternal origin. Seven cytb haplotypes were found in the 33 mithun, and the phylogenetic tree for these haplotypes clearly showed three embranchments involving five gaur types, a B. indicus type, and a B. taurus type. Sixteen Myanmar and 12 Bhutan mithun had gaur haplotypes, while a B. indicus haplotype was found in three Myanmar and one Bhutan mithun. The B. taurus haplotype was detected in a single Myanmar animal. These results demonstrated that the principal maternal origin of mithun was gaur and suggested that it was directly domesticated from gaur. However, some introgression of domestic cattle existed in current mithun populations. The presence of cattle mtDNA raised the question of how many cattle nuclear genes might have been integrated into the gene pool of mithun.     

Greenhouse gases emission from paddy soil during the fallow season with and without winter flooding in central Japan

Many papers on measurements of greenhouse gases (GHGs) emission in rice paddies during a rice cropping season have been published. During a non-cropping season between Nov. and Apr., we investigated direct and indirect GHGs emissions in rice paddies. The indirect GHGs emission was evaluated as the amount of dissolved gases leaching from the paddy fields. Water management practices for the experiment were (1) continuous flooding (CF) and (2) non-flooding (NF). Although the direct CO₂ emission in the CF treatment was remained nearly zero during the non-cropping period, direct CO₂ emission in the NF treatment was continuously observed throughout the non-cropping period. The concentration of dissolved N₂O in the NF treatment was below the detection limit of the instrument during the non-cropping period except immediately after the flooding and before the drainage. The concentration of dissolved N₂O kept approximately 2 µg L^?1 during the non-cropping period in the CF treatment. The direct CH₄ emission and dissolved CH₄ were not observed during the non-cropping period. Total gas emission in the NF treatment was 10 times as large as that in the CF treatment. Direct CO₂ emission accounted for more than 90 % of the total emission in both treatments.     

Feeding ecology of Swinhoe’s tree lizard (Diploderma swinhonis (Günther, 1864)) in Hyuga City,Miyazaki Prefecture, Japan

Swinhoe’s tree lizard (Diploderma swinhonis: D. swinhonis) is an arboreal agamid that is native to Taiwan. In Taiwan, the lizard is considered to be a generalist that feeds primarily on ants and a diversity of small insect prey by employing an opportunistic sit-and-wait foraging strategy. In Japan, D. swinhonis is considered as an invasive alien species that was discovered in Hyuga city, Miyazaki Prefecture, in 2016. Despite concerns about the impact of D. swinhonis on native fauna, little information about the diet of this alien species has been published to date. This study, therefore, investigated the feeding ecology of D. swinhonis in Hyuga city to evaluate their potential impact on the ecosystem. Specifically, prey preference was investigated by examining the stomach contents of males, females, and juveniles captured from April to December 2020 and in March 2021. The results showed that the lizards in Hyuga preyed upon a wide variety of invertebrates as in Taiwan, while ants accounted for the largest proportion of the prey items consumed regardless of sex, age or changes in season. These findings indicated that D. swinhonis might cause a decrease in the abundance of the native insect fauna of Hyuga city or competition with native lizards for foods in Hyuga city. Since its impact is not currently apparent, it’s necessary to monitor its effect in the future.     

Behavior of phenolic substances in the decaying process of plants

The changes in amount of ether-extractable phenolic substances, individual phenolic adds, organic matter content, and pH value in the decaying process of rice straw were compared at 10, 30, and 50°C under moist and flooded conditions for 70 days.

1) The changes in pH value with time varied markedly according to temperature and water conditions.

2) Phenolic substances in the ether-extractable fraction obtained from the acidified solution of alkaline methanol extract contained undetected phenolic compounds in amounts larger than the phenolic adds detected by gas chromatography. pH value during incubation was hardly attributable to these phenolic substances because of their small quantity.

3) The changes in amount of the ether-extractable phenolic substances with time was mainly due to phenolic compounds other than phenolic acids, and influenced largely by the temperature and water conditions. Their formation and degradation took place rapidly at high temperatures under flooded conditions.

4) From the plots of individual phenolic acids vs. time, it was tentatively concluded that phenolic acids contalned in non-decayed straw were rapidly degraded in the earlier stage, and some of them were newly produced from ether-unextractable precursors in the later stage. These reactions occurred rapidly at high temperatures, especially under flooded conditions.

5) The content of p-hydroxybenzolc acid increased simultaneously with a rapid decrease in p-coumaric acid during the incubation ot straw. The relationship between vanillic acid and ferulic acid was the same.     

Overexpression of the LASAP2 gene for secretory acid phosphatase in white lupin improves the phosphorus uptake and growth of tobacco plants

Secretion of acid phosphatase (APase) from the roots to take up phosphorus (P) is a well-known strategy of plants under P-deficient conditions. White lupin, which shows vigorous growth in low-P soils, is noted for its ability to secrete APase under P-deficient conditions. The APase secreted by white lupin roots is stable in soil solution and shows low substrate specificity, suggesting that genetic modification of plants using the APase gene LASAP2 might improve their ability to use organic P. The objective of the present study was to evaluate the potential of LASAP2 transgenic plants to increase organic P utilization. Dry matter production and P accumulation were higher in LASAP2 transgenic tobacco plants grown in gel media containing soluble phytate as the sole P source than in wild-type tobacco plants. Phosphorus uptake by the transgenic plants also increased in soil culture conditions. LASAP2 was apparently more effective in the liberation of organic P, including phytate, in the soil than the native tobacco APase. Thus, the enzymatic stability of LASAP2 in the soil appears to be an important factor for P acquisition.     

Application of single‐step genomic best linear unbiased prediction with a multiple‐lactation random regression test‐day model for Japanese Holsteins

This study aimed to evaluate a validation reliability of single‐step genomic best linear unbiased prediction (ssGBLUP) with a multiple‐lactation random regression test‐day model and investigate an effect of adding genotyped cows on the reliability. Two data sets for test‐day records from the first three lactations were used: full data from February 1975 to December 2015 (60 850 534 records from 2 853 810 cows) and reduced data cut off in 2011 (53 091 066 records from 2 502 307 cows). We used marker genotypes of 4480 bulls and 608 cows. Genomic enhanced breeding values (GEBV) of 305‐day milk yield in all the lactations were estimated for at least 535 young bulls using two marker data sets: bull genotypes only and both bulls and cows genotypes. The realized reliability (R²) from linear regression analysis was used as an indicator of validation reliability. Using only genotyped bulls, R² was ranged from 0.41 to 0.46 and it was always higher than parent averages. The very similar R² were observed when genotyped cows were added. An application of ssGBLUP to a multiple‐lactation random regression model is feasible and adding a limited number of genotyped cows has no significant effect on reliability of GEBV for genotyped bulls.     

Long-term effects on tree regeneration of soil scarification with microtopography manipulation in mixed forests of central Hokkaido,northern Japan

Natural regeneration of canopy tree species is generally poor under a selective cutting regime practised in mixed conifer–hardwood stands on Hokkaido, northern Japan, and is prevented by dense bamboo layers in the understory. To promote tree regeneration, we scarified soil in ten sites, with elevations ranging from 420 to 760 m, in 1979, with a rake-equipped bulldozer to produce three different artificial microtopographies (concave, flat, and convex). Twenty-six years after scarification, six canopy tree species (Acer mono, Abies sachalinensis, Betula ermanii, B. maximowicziana, Kalopanax pictus, and Picea jezoensis) had become well established. Abies sachalinensis and B. ermanii regenerated at all sites. Picea jezoensis was well established in high-elevation sites, whereas other hardwood tree species (A. mono, B. maximowicziana, and K. pictus) were well established at low-elevation sites. The Betula species dominated upper layers of regenerated trees, and two conifer species (A. sachalinensis and P. jezoensis) occupied lower layers. Regenerated densities of four (of six) major tree species were positively correlated with standing timber volume of mother trees, whereas those of shade-intolerant species (two Betula species and K. pictus) were negatively correlated with standing timber volume of all canopy trees. Small-seeded species (P. jezoensis and the two Betula species) had higher regeneration densities on convex sites than on other microtopographies. Adequate seed supply, convex substratum for small-seeded species, and control of light conditions for shade-intolerant species should be taken into account when planning regeneration of desirable tree species in central Hokkaido.     

Evaluation of suitable conditions for natural regeneration of <Emphasis Type="Italic">Picea jezoensis</Emphasis> on fallen logs

The abundance of Picea jezoensis, a major conifer tree species in Hokkaido, northern Japan, is currently decreasing due to the lack of suitable conditions for recruitment and intensive harvests. To contribute to the development of sustainable forest management in Hokkaido, suitable substrates for natural regeneration of P. jezoensis were evaluated during a 4-year experimental study using seed additions in a natural coniferous forest. The environmental conditions (moss height, log hardness, extent of the humus layer, and light conditions) of fallen logs were measured. Moss height was categorized into three groups: 0 mm, Bark; 0–20 mm, Mthin; and ≥20 mm, Mthick. The germination rates of P. jezoensis were highest on Mthin, intermediate on Bark, and lowest on Mthick. Survival rates were low on Mthick, did not differ between Bark and Mthin, and increased with enhanced light. Growth increased with light, but the root allocation of seedlings was not affected by any environmental conditions. From these results, we determined that fallen logs with no or thin moss cover under bright conditions were most suitable for P. jezoensis regeneration. We discuss the generality of our results in relation to a co-occurring tree species in Hokkaido and the results of other regions.     

Fucoxanthinol,Metabolite of Fucoxanthin,Improves Obesity-Induced Inflammation in Adipocyte Cells

Fucoxanthin (Fx) is a marine carotenoid found in edible brown seaweeds. We previously reported that dietary Fx metabolite into fucoxanthinol (FxOH), attenuates the weight gain of white adipose tissue of diabetic/obese KK-A^y mice. In this study, to evaluate anti-diabetic effects of Fx, we investigated improving the effect of insulin resistance on the diabetic model of KK-A^y mice. Furthermore, preventing the effect of FxOH on low-grade chronic inflammation related to oxidative stress was evaluated on 3T3-L1 adipocyte cells and a RAW264.7 macrophage cell co-culture system. A diet containing 0.1% Fx was fed to diabetic model KK-A^y mice for three weeks, then glucose tolerance was observed. Fx diet significantly improved glucose tolerance compared with the control diet group. In in vitro studies, FxOH showed suppressed tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1) mRNA expression and protein levels in a co-culture of adipocyte and macrophage cells. These findings suggest that Fx ameliorates glucose tolerance in the diabetic model mice. Furthermore, FxOH, a metabolite of Fx, suppresses low-grade chronic inflammation in adipocyte cells.     

Discoloration induced by Raffaelea quercivora isolates in Quercus serrata logs and its relation to phylogeny: a comparison among isolates with and without the Japanese oak wilt incidence including outside of Japan

Japanese oak wilt (JOW) has been prevalent in Japan since the late 1980s. Infections of the fungus, Raffaelea quercivora Kubono et Shin. Ito, which is transmitted by an ambrosia beetle [Platypus quercivorus (Murayama)], can cause JOW. Although R. quercivora, P. quercivorus, and oak trees are distributed in other Asia–Pacific countries, the incidence of JOW has not been reported outside Japan. In this study, we collected R. quercivora isolates from 5 Asian countries, including Japan, and compared their ability to induce sapwood discoloration by inoculating Q. serrata logs. The tangential widths of the discoloration in sapwoods inoculated with non-Japanese isolates were equivalent to or greater than those of the 2 Japanese isolates. This indicates that a lack of JOW incidence outside Japan is not because of the lowered ability of R. quercivora to spread discoloration compared with the Japanese isolates. Statistical analyses of the relationship between discoloration and phylogeny based on DNA sequences of actin and chitin synthase showed that the discoloration width was independent of phylogenetic relatedness among the isolates. To discuss why the occurrence of JOW has not been reported outside Japan, further studies (e.g., on host susceptibility and P. quercivorus aggression) throughout Asia are needed.