Identification of quantitative trait loci for downy mildew resistance in cucumber (Cucumis sativus L.)

Downy mildew, caused by Pseudoperonospora cubensis (Berk. & Curt.) Rostov, is one of the most economically important foliar diseases in cucumber (Cucumis sativus L.). Cucumber line CS-PMR1, derived from self-pollination of USDA Plant Introduction 197088, has a high level of resistance to downy mildew and is considered to be promising breeding material. In this study, we performed quantitative trait locus (QTL) analysis for downy mildew resistance using 111 recombinant inbred lines (RILs) derived from a cross between CS-PMR1 and the old Japanese cultivar Santou, which exhibits moderate resistance. The resistance of the RILs and their parents was evaluated by diverse methods using different plant organs (cotyledons, true leaves), stages (seedlings and adult plants), and evaluation criteria (lesion expansion and extent of sporulation). The high resistance of CS-PMR1 was associated with many QTLs with relatively small effects, whereas the moderate resistance of Santou was associated with one major QTL and possibly two others with relatively small effects. In all assays, the major QTL at which the Santou allele was associated with increased resistance had the largest effect. This QTL allele from Santou and several of the most effective QTL alleles identified in CS-PMR1 should be highest priority for selection to efficiently breed new cultivars that carry adequate levels of downy mildew resistance.     

Evaluation of Loads and Sources of Heavy Metals in Tama River, Tokyo

The loads and sources of heavy metals (Cd, Co, Cu, Mn, Mo, Ni, Pb, V, and Zn) in the midstream of Tama River were evaluated on the basis of their chemical analyses in ordinary and stormwater runoff from July 2007 to November 2008. Tama River is one of the three major rivers flowing into Tokyo Bay. The total annual water discharges differed largely for 2007 and 2008, depending on the scales of typhoon rainfalls and other heavy rainfalls in each year. The concentrations of the metals other than Mo in the river did not change markedly at a flow rate of less than approximately 200 m³ s^?1, but at higher flow rates, the concentrations of all the metals increased linearly with the increase in the log of flow rate (r ²?=?0.94–0.99). The annual loads of heavy metals for 2007 and 2008 were estimated using regression equations between the above parameters and the hourly flow rate data for each year. For the metals other than Mo, the contribution of the loads at higher flow rates (>200 m³ s^?1) was much larger than that at lower flow rates (<200 m³ s^?1), showing the importance of the particulate loads (primarily crustal materials) during storm runoff following typhoon rainfalls and other heavy rainfalls. In contrast, the loads of Mo at lower flow rates accounted for major portions (56–78%) of the total loads, because of a relatively small contribution of particulate load during storm runoff. The contribution of the loads of Mo, Zn, Cd, Cu, and Ni at lower flow rates to the annual loads was larger than that of other metals. It was found that the concentrations of these metals in ordinary runoff are strongly affected by the discharge of treated water from sewage treatment plants which are located along the catchment. Thus, treated water from sewage treatment plants may be the primary source contributing to the present pollution of Mo, Zn, Cd, Cu, and Ni in Tokyo Bay.     

Collembolan community dynamics during deciduous forests regeneration in Japan

The structure and feeding group composition of collembolan communities were studied in secondary deciduous forests of different ages to investigate the collembolan community response to environmental changes associated with forest cycles. The study was carried out at eight sites forming a chronosequence (1, 4, 12, 24, 51, 54, 71 and 128 years after clear cutting) of deciduous forest stands in northern Ibaraki (Japan). Total collembolan density and species richness was low at the 1-year-old site, and there was little difference in density among sites over 4 years of age. The density of sucking feeders was especially low at the 1-year-old site. Species richness of trees of a diameter at breast height (DBH)<5 cm positively correlated with the density of fungal feeders. Species richness of total Collembolans and of sucking feeders correlated positively with the water content of the organic layer. Ordination of the collembolan community with Canonical Correspondence Analysis suggested that species richness of larger trees (DBH 5 cm) contributed to the differences in species composition of fungal feeders and sucking feeders. We conclude that total abundance and species richness of collembolans recovered within 4 years after clear-cutting, but species composition of fungal feeders and sucking feeders took longer to recover.     

Indicated detection of two unapproved transgenic rice lines contaminating vermicelli products

We analyzed the DNA fragments extracted from four rice vermicelli products. The Bacillus thuringiensis (Bt) rice line, which has a construct similar to the GM Shanyou 63 line, was detected in some vermicelli products by identification of the junction region sequence between rice Act1 promoter and the Cry1Ac gene, and that between Cry1Ac and nos. In addition, we also detected a different Bt rice line by means of the junction region sequence between the maize ubiquitin promoter and cry1Ab gene and that between the cauliflower mosaic virus 35S promoter and the hygromycin phosphotransferase in some vermicelli products. Accordingly, we for the first time have detected the two transgenic Bt rice lines contaminating rice vermicelli samples. Furthermore, we developed a duplex real-time polymerase chain reaction (PCR) method for the simultaneous detection of both Bt rice lines.     

Effect of High β-Glucan Barley on Serum Cholesterol Concentrations and Visceral Fat Area in Japanese Men—A Randomized,Double-blinded,Placebo-controlled Trial

This study investigated whether the consumption of a diet in which high-β-glucan barley replaced rice would reduce the visceral fat area as well as the serum low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) in hypercholesterolemic Japanese men. A randomized, double-blinded, placebo-controlled intervention study was conducted in 44 hypercholesterolemic Japanese men with a body mass index (BMI) >22 kg/m². The subjects were randomly assigned to groups consuming either rice (placebo group) or a mixture of rice and pearl barley with a high β-glucan content (test group, 7.0 g β-glucan per day) for 12 weeks. Blood samples were taken, and CT scan obtained before the trial and every four weeks during the trial. The pearl barley intake significantly reduced serum concentrations of LDL-C (P = 0.041) and TC (P = 0.037) during the trial. Significant differences between the test and placebo groups were found for the visceral fat (P = 0.039), BMI (P = 0.015), and waist circumference (P = 0.011) at the end point. The consumption of pearl barley with a high β-glucan content reduces not only LDL-C but also visceral fat area.     

Fish meal replacement by soy protein from soymilk in the diets of red sea bream (Pagrus major)

Six isoenergetic diets were formulated as follows: fish meal (FM) 700 g kg^–1 (control, C), FM 300 g kg^–1 + soy protein concentrate 300 g kg^–1 (SPC), FM 300 g kg^–1 + enzyme‐treated SPC 300 g kg^–1 (ESC), FM 170 g kg^–1 + soy protein isolate 300 g kg^–1 (SPI), FM 160 g kg^–1 + enzyme‐treated SPI 300 g kg^–1 (ESI) and FM 150 g kg^–1 + conglycinin 300 g kg^–1(CG). Forty fish (3.9 g) were randomly distributed into each of eighteen 300‐L tanks, fed twice daily until satiation for 8 weeks. The final body weight, specific growth rate and condition factor did not show significant differences among the fish fed with diets C, SPC, ESC and ESI (p > .05). The survival was significantly lower in fish fed with diets SPI and CG. Feed efficiency was significantly higher in fish fed with diets SPC and C than in fish fed with other diets (p < .05). There were no significant differences in nutrients retention efficiencies in fish fed with diets C, SPC, ESC and ESI. A significantly higher phosphorus retention efficiency in fish fed with soymilk protein diets resulted in lower phosphorus discharge to the environment (p < .05). These results suggest that the soymilk proteins can comfortably replace 570–770 g FM kg^–1 diet of red sea bream juvenile, which will ensure significant ecological benefits through reducing phosphorus load to the environment.