The relationship of readily decomposable organic matter of the paddy soil to its colloidal complexes

The soil nitrogen of paddy soil is found to exist in the form of organic and inorganic nitrogen. In general, the content of inorganic nitrogen is so low that it is mainly occupied by organic nitrogen. Such soil organic nitrogen is characterized by large resistance to decomposition by soil microorganisms, and so its mineralization occurs to a small extent in most cases. However, as revealed by M. Shioiri¹⁾ and T. Harada et al. ^2,3), by some appropriate treatment of paddy soil, a part of soil organic nitrogen becomes decomposed by microorganisms and mineralized under flooded condition. Among various treatment, for example, are Presented the followings: (1) air-drying of soil Prior to flooding; (2) raising the soil temperature during the flooded condition; (3) raising the soil reaction (pH 9.0) by addition of weak alkali solution; (4) the addition of neutral salts such as Nafiuoride, Na-phosphate, Na-oxalate etc., which make soil humus peptizable.     

Characterization of the perylenequinone pigments in Japanese Andosols and Cambisol

The green fraction of humic acid (Pg) and the chloroform-extractable green fraction (CEGF) are characteristic soil organic matter (SOM) components. These alkaline solutions are green-colored due to the presence of 4,9-dihydroxyperylene-3,10-quinone (DHPQ) chromophore. While both of which are potential indicators for the effect of land use and paleoclimatic environment in the fields of soil science as well as geochemistry, CEGF as well as its relationship with Pg in soils are not yet fully documented. In this study, we firstly investigated the chemical properties of soil CEGF fractions by ultraviolet–visible (UV–Vis) and infrared (IR) method. Two CEGF components were separated by sequential liquid-liquid extraction using aqueous ammonium hydroxide (NH₄OH) followed by aqueous sodium hydroxide (NaOH). Results showed that the UV–Vis spectral shape of NH₄OH-extractable component is very similar to that of DHPQ, except that it is red-shifted. The solubility and UV–Vis spectrum of the NaOH-extractable fraction were completely identical with those of synthesized DHPQ. Their IR spectral shapes were also almost the same. Subsequently, the distribution of CEGF in humic acid (HA), fulvic acid (FA) and humin (HN) from Japanese Andosols and Cambisol was quantitatively evaluated by sequential extraction. Most of CEGF was detected in the HA (60–78%) and HN (22–40%), but not in the FA. While the UV–Vis spectral shape of CEGF extracted from Andosols HAs showed a relatively higher proportion of DHPQ than its derivative, the opposite was observed in Cambisol HA, whose CEGF is similar to that of sclerotium grain (one of the possible origin of CEGF). These results suggest the diversity of CEGF-producing soil fungi. Quantitative data also indicated that 35–49% of Pg consisted of a chloroform-soluble fraction (i.e., CEGF) and the remaining 51–65% of Pg was chloroform-insoluble. Based on these results, we propose that CEGF is composed of DHPQ and DHPQ-derivatives and that CEGF is one of the major fractions of Pg.     

Enzymatic dehydrogenative polymerization of urushiols in fresh exudates from the lacquer tree, Rhus vernicifera DC

Fresh exudates from the lacquer tree, Rhus vernicifera DC, were extracted with acetone and the solution was chromatographed to isolate monomer, dimer, trimer, and oligomer fractions of urushiols. Constituents of the monomeric and dimeric fractions were then identified by two-dimensional (2D) 1H-13C heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bond coherence (HMBC) NMR spectroscopic techniques. The results showed that the monomeric fraction contained 3-[8'Z,11'E,13'Z-pentadecatrienyl]catechol (1), 3-[8'Z,11'Z,14'-pentadecatrienyl]catechol (2), and 3-pentadecanyl]catechol (3), which was verified by HPLC analysis. The dimeric fraction contained 8'-(3' ',4' '-dihydroxy-5' '-alkenyl)phenyl-3-[9'E,11'E,13'Z-pentadecatrienyl]catechol (4), 14'-(3' ',4' '-dihydroxy-5' '-alkenyl)phenyl-3-[8'Z,10'E,12'E-pentadecatrienyl]catechol (5), 2-hydroxyl-3- or -6-alkenylphenyl ethyl ether (6), 14'-(3' ',4' '-dihydroxy-2' '-alkenyl)phenyl-3-[8'Z,10'E,12'E-pentadeca-trienyl]catechol (7), 15'-(2' '-hydroxy-3' '- or -6' '-alkenyl)phenyloxy-3-[8'Z,11'Z,13'E)-pentadecatrienyl]catechol (8), 14'-(2' ',3' '-dihydroxy-4' '-alkenyl)phenyl-3-[8'Z,10'E,12'E-pentadecantrienyl]catechol (9), 1,1',2,2'-tetrahydroxy-6,6'-dialkenyl-4,3'-biphenyl (10), 1,1',2,2'-tetrahydroxy-6,6'-dialkenyl-4,4'-biphenyl (11), 1,1',2,2'-tetrahydroxy-6,6'-dialkenyl-5,4'-biphenyl (12), and 1,2,1'-trihydroxy-6,6'-dialkenyldibenzofuran (13) as constituents. In addition, dimeric ethers and peroxides, such as compounds 14 and 15, were produced by autoxidation of monomeric urushiols in atmospheric air. The possible reaction mechanisms for the dehydrogenative polymerization of urushiols by Rhus laccase present in the fresh raw exudates under the atmospheric oxygen are discussed on the basis of structures identified. This is of primary importance because the use of the urushi exudates as coating materials does not involve organic solvents and is an environmentally friendly process.     

Analysis of methoxyfenozide residues in fruits, vegetables, and mint by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

Methoxyfenozide [3-methoxy-2-methylbenzoic acid 2-(3,5-dimethylbenzoyl)-2-(1,1-dimethylethyl) hydrazide; RH-2485], in the formulation of INTREPID, was applied to various crops. Analysis of methoxyfenozide was accomplished by utilizing liquid-liquid extraction and partitioning, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method validations for fruits, vegetables, and mint are reported. Methoxyfenozide mean recoveries ranged from 72 to 129% over three levels of fortification. The overall average of mean recoveries is 97 +/- 10%. The limit of quantitation for fruits, artichoke, cucumber, squash, and refined sugar was 0.010 ppm, with a detection limit of 0.005 ppm. For all other crops, the limit of quantitation was 0.050 ppm, with a detection limit of 0.025 ppm. No residues were found greater than the limit of quantitation in control samples. Residues above the limit of quantitation were found in all matrices except refined sugar. Foliage (bean, beet, pea, and radish) had greater residue levels of methoxyfenozide residue than their corresponding roots or pods. Other crop matrices contained <1.0 ppm of methoxyfenozide except artichoke, which had a mean of 1.10 ppm.     

Determination of antioxidant potential of volatile extracts isolated from various herbs and spices

Antioxidant activities of volatile extracts isolated from thyme, basil, rosemary, chamomile, lavender, and cinnamon were evaluated by two independent assays: the aldehyde/carboxylic acid assay and the conjugated diene assay. The volatile extracts were prepared from dried herbs and spices using liquid-liquid continuous extraction following steam distillation under reduced pressure (55 degrees C and 95 mmHg). The antioxidant activities of the extracts decreased in the following order in both of the lipophilic assay systems: thyme > basil > rosemary > chamomile > lavender and cinnamon. Thyme and basil extracts inhibited the oxidation of hexanal for 40 days at the levels of 10 microg/mL and 50 microg/mL, respectively. The extracts of thyme and basil were effective in retarding methyl linoleate deterioration at 40 degrees C, with activity increasing with concentration in the range 10-200 microg/mL. At a concentration of 50 microg/mL, thyme extract was similar in antioxidant activity to BHT and alpha-tocopherol in the conjugated diene assay. The antioxidant potentials of the volatile extracts used in this study were accurately measured by the lipophilic systems, such as the aldehyde/carboxylic acid assay and the conjugated diene assay.     

Effects of a probiotic bacterial <Emphasis Type="Italic">Lactobacillus rhamnosus</Emphasis> dietary supplement on the crowding stress response of juvenile Nile tilapia <Emphasis Type="Italic">Oreochromis niloticus</Emphasis>

To test the effects of probiotic bacteria against crowding stress, juvenile Nile tilapia Oreochromis niloticus were fed commercial feed supplemented with 1 × 10¹⁰ cfu/g pellets of Lactobacillus rhamnosus for 3 weeks. The fish were confined and subjected to crowding for 7 and 14 days after which their physiological condition was investigated. The administration of probiotic prophylaxis improved growth performance even in the stressed fish. After 7 days of stress exposure, fish receiving probiotic-supplemented feed showed proactive behavior and coping responses to the stressor, as evidenced by elevated plasma glucose levels and osmolality, stabilized plasma electrolytes, and a higher RNA:DNA ratio. Fish stressed for 7 days and fed normal commercial diet showed impairment of plasma electrolytes; after 14 days, the plasma osmolality, electrolytes, glucose, and RNA:DNA ratio decreased, indicating physiological maladaptation to the stressor. The growth rate was also found to be reduced, suggesting that energy demand exceeded the energy available from metabolism and dietary uptake. This latter effect was not observed in fish fed the probiotic-supplemented diet. The results suggest that probiotic bacteria prophylaxis may increase energy availability for metabolic support of the crowding stress response and improve the stress coping capacity of fish.     

Model-based forecasting of twig canker incidence of bacterial spot of peach in Fukushima Prefecture

Bacterial spot caused by Xanthomonas arboricola pv. pruni (Xap) is the most important disease that affects peach production. A disease-forecasting model was developed to help growers decide when to apply bactericides and remove diseased, last-year twigs. To predict the incidence of “spring cankers”, peach twigs damaged by Xap, we used 12 years (2009–2020) of data from Fukushima Prefecture to develop a forecasting system using a hierarchical Bayesian model (HBM). The model included the number of fields with a bacterial spot incidence (BSI) on leaves?≥?10% in late September of the previous season and the number of days with rain (≥?10 mm/day) and maximum wind speed (≥?5 m/s) during the previous October as predictors. Using a best-fit cutoff value based on a receiver operating characteristic (ROC) curve, the model achieved a 0.836 accuracy, 0.804 sensitivity, 0.847 specificity, 0.847 precision, and 0.712 F-measure. The model was validated using a fourfold cross-validation (CV) procedure and achieved an average accuracy of 0.847. Thus, the model explained 65.7% of the variability compared to observed frequencies with predicted probabilities of twig canker incidence (TCI)?≥?2% from April to May 2009 to 2020 in Fukushima Prefecture. These results suggest that this disease-forecasting model using HBM based on 12 years of historical data can be used to predict the risk of twig cankers of bacterial spot of peach.

     

Production of a desirable Brassica oleracea CMS line using an alloplasmic B. rapa CMS line carrying Diplotaxis erucoides cytoplasm as a bridge plant

In Brassica oleracea, production of F₁ hybrid seeds mainly makes use of the improved Ogura cytoplasmic male sterile (CMS) line. However, reliance on one particular line is a risk, and it would be advantageous to develop other CMS lines. In this study, we transferred Diplotaxis erucoides cytoplasm to B. oleracea cultivars using an alloplasmic B. rapaCMS line as a bridge plant to avoid incompatibility between donor and recipient plants. The new B. oleraceaCMS lines, which were derived by four generations of backcrossing, had small rudimentary anthers with no pollen grain and showed complete male sterility. There was no functional defect in other floral organs, and the ability to receive normal pollen did not appear to be impaired. Moreover, the B. oleraceaCMS lines carrying D. erucoides cytoplasm had larger leaf areas and a normal plastochron. As a consequence, the B. oleraceaCMS lines carrying D. erucoides cytoplasm have the potential to be valuable alternatives for use in commercial B. oleracea hybrid seed production.     

Seasonality of serum levels of vitellogenin in male Japanese whiting, Sillago japonica, reared under natural temperature and photoperiod

ABSTRACT:   Because blood vitellogenin (Vg) has been considered a biomarker for environmental estrogens, the basal levels of Vg and 17β-estradiol (E₂) were determined in male Japanese whiting reared under natural conditions. Serum levels of Vg and E₂ were measured and gonadal development was assessed by gonadosomatic index (GSI) and histological observation in 8–10 male fish at monthly intervals throughout the annual reproductive cycle. Serum E₂ was <60 pg/mL throughout the study period. In contrast, serum Vg exhibited seasonal changes: serum levels of Vg gradually increased from April to May (mean 63 ± 13 ng/mL and 124 ± 48 ng/mL in April and May, respectively), and then reached a peak value (mean 352 ± 68 ng/mL) in June. Thereafter, serum Vg gradually decreased, reaching undetectable levels (<50 ng/mL) in October. Serum levels of Vg tended to increase in the male fish in which the GSI was >1%. Histological observation revealed that testes in such male fish were in active spermatogenesis and then all of the testes of male fish in which serum Vg decreased to ND levels were regressed. These results suggest that Vg productive potency (sensitivity to estrogens) may increase in the spermatogenic stage, resulting in production of Vg in response to very low levels of natural or xenobiotic estrogens.