Genetic variation in barley of crossability with wheat and its quantitative trait loci analysis

To study genetic variation in crossability, 80 barley accessions of diverse geographic origin consisting of 50 wild barleys (H. vulgare ssp. spontaneum or ssp. agriocrithon) and 30 cultivated barleys (H. vulgare ssp. vulgare) were crossed as the male parent with a highly crossable wheat variety, Shinchunaga. Crossabilities, expressed as the percentage of pollinated florets giving embryo-containing caryopses, ranged from 0% to 68.6%. Barley accessions from East Asia had generally a low crossability, while barley accessions from other regions exhibited a wider range of crossability including highly crossable genotypes. No significant difference in mean crossability was found between wild and cultivated barleys. To estimate the number and location of barley genes controlling the crossability, doubled haploid lines derived from the cross between the barley varieties Steptoe and Morex were crossed as the male parent with wheat. Quantitative trait loci (QTL) analysis using molecular markers identified four QTL. These were mapped to the centromeric regions of chromosomes 2H, 3H and 5H and the short arm of chromosome 7H. The QTL on chromosomes 3H and 5H had larger effects than those on chromosomes 2H and 7H. The four QTL collectively explained 35.4% of the total variance under a multiple QTL model. Relationships of the QTL identified in the present study with previously reported crossability genes of barley and wheat are discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Suitability of Japanese codling as a raw material for surimi-based products revealed by primary sequence analysis of myosin heavy chain and thermal gel properties

Fisheries Science - Complementary DNA encoding a part of myosin heavy chain was cloned from fast skeletal muscle of Japanese codling Physiculus japonicus. Japanese codling, a frequent catch off the...     

Microbial and chemical properties of <Emphasis Type="Italic">aji-no-susu</Emphasis>, a traditional fermented fish with rice product in the Noto Peninsula,Japan

Aji-no-susu is a Japanese fermented fish product prepared from salted horse mackerel Trachurus japonicus, and cooked rice. We studied the organic acid and free amino acid contents and microflora in 12 aji-no-susu products to clarify their features as a lactic-acid-fermented food. Salinity of the samples was approximately 7.0% (rice portion) and 6.0% (fish portion) (w/w). Water activity was approximately 0.9, and pH was approximately 4.4 and lower. In the rice portions, lactic acid content was very high (57 mg/g sample). The predominant amino acids were alanine (2.3 mg/g rice portion) and lysine (2.1 mg/g). In the case of long-fermented (4 and 12 months) aji-no-susu, a high content of gamma-aminobutyric acid (GABA, 1.5 and 1.4 mg/g) was detected. Total viable counts in rice and fish portions were 7.7 and 7.4 log colony-forming units (cfu)/g, respectively. The number of lactobacilli in the rice and fish portions was 7.3 and 7.1 log cfu/g, respectively. Yeasts were detected in eight samples. Furthermore, acid-tolerant lactic acid bacteria (LAB) (Lactobacillus plantarum), GABA-producing LAB (Lactobacillus sp.), and halophilic or halo-tolerant yeast (Debaryomyces hansenii) were isolated and identified. Results in this study indicate that aji-no-susu is a typical traditional lactic-acid-fermented fish product.     

树木剪枝堆肥与传统堆肥对土壤化学性质的影响

通过与完熟牛粪肥、腐熟树叶堆肥、树皮畜粪混合堆肥3种传统堆肥进行对比,并以不施肥土壤作对照,研究树木剪枝堆肥对土壤中的全氮全碳含量、阳离子交换能力、有效盐基阳离子浓度的影响.结果表明:施肥1 a后完熟牛粪堆肥、腐熟树叶堆肥、树皮畜粪混合堆肥和树木剪枝堆肥氮素耗损分别为1.10,1.30,1.33和1.44 g/kg,剪枝堆肥中的有机氮素更容易转化为容易被土壤吸收的无机氮素;完熟牛粪堆肥、腐熟树叶堆肥、树皮畜粪混合堆肥和树木剪枝堆肥的全碳损耗分别为1.37,2.73,1.84和4.37 g/kg,相比于传统堆肥,剪枝肥的全碳损耗更大,被分解的碳素明显高于其他传统有机肥;剪枝肥料能加快土壤中微生物的分解效率,导致其微生物活性远高于其他施肥处理;剪枝肥施用1 a后,土壤阳离子交换量、有效盐基阳离子浓度等均显著增加(P＜0.05),从而增加土壤中可被植物吸收的微量营养元素.     

Recent studies on biological control of plant diseases in Japan

Microorganisms play an enormously important role in plant disease control. Research on biological control of plant pathogens has received major impetus and attracted many researchers during the past few decades due to the increased public concern on hazards associated with the use of synthetic pesticides. From research on utilizing specific antagonistic microorganisms, many effective biological control agents (BCAs) have been found and are increasingly implemented in integrated pest management strategies to control plant diseases. Here current research results on biological control against plant diseases carried out in Japan are reviewed by focusing on major categories of BCAs: fungi, bacteria and actinomycetes and attenuated viruses.     

Bacterial leaf spot and blight of crucifer plants (Brassicaceae) caused by Pseudomonas syringae pv. maculicola and P. cannabina pv. alisalensis

Bacterial leaf spot and blight diseases caused by Pseudomonas syringae pv. maculicola (Psm) and P. cannabina pv. alisalensis (Pcal) are becoming a significant concern for producers of crucifer crops worldwide. Since Psm was first described in 1911, many have reported on its diverse phenotypic, genetic and pathogenic characteristics. Japanese isolates of Psm are also heterogeneous and differ in their host preferences. Pcal was first described in 2002 and has quickly spread globally. Recent work demonstrated that some isolates that had been identified as Psm are actually Pcal. Pcal was also shown to be split into two groups, A and B, based on bacteriological properties, genetic traits and pathogenicity. Group A of Pcal consists mostly of isolates from Japanese radish and radish, isolated before 1990s, that are more aggressive on radish leaves but less aggressive on other Brassica plants compared with group B. Group B of Pcal consists of recent isolates from various crucifer plants including the pathotype of Pcal. In this review, we suggest that group A of Pcal may have existed since the 1950s and survived as a relatively minor pathogen on radish or Japanese radish, whereas group B emerged in the late 1990s, causing global epidemics because of its stronger virulence on various Brassica crops. We also suggest that emergence of a new group of a pathogenic bacterium may cause a re-emergence or new epidemics of a disease that previously was of minor importance.     

A preliminary study to understand the transport process for the eggs and larvae of Japanese Pacific walleye pollock Theragra chalcogramma using particle-tracking experiments based on a high-resolution ocean model

We developed a realistic 1/50° high-resolution ocean model capable of resolving submesoscale variability, and performed particle-tracking experiments based on this ocean model to identify elements that significantly affect the transport of the eggs and larvae of the Japanese Pacific walleye pollock Theragra chalcogramma into Funka Bay. The high-resolution model reproduced representative features of the oceanographic conditions of the main spawning area and season. A comparison of particle-tracking experiments performed under the passive transport condition based on high-resolution (1/50°) and low-resolution (1/10°) ocean models showed that high-resolution modeling is essential in order to realistically simulate the transport process. In this regard, however, the vertical motion of particles cannot be explained by the passive transport condition, as it leads to unrealistically deep sinking of particles in the simulation. Turning our attention to feasible non-passive transport conditions, we then incorporated the buoyancy motion of particles and conducted additional experiments that mainly differed in the particle density adopted. We clarified that buoyancy is an important factor in the retention of particles near the sea surface, and that the ratio of the particles that remain in Funka Bay to the number of particles released is sensitive to the vertical motions/positions of the particles, implying that it is necessary to model this vertical motion more accurately by incorporating more realistic biological processes or a statistical distribution into the particle-tracking model.     

Insulin/insulin-like growth factor-like activity in the aqueous extracts of the rotifer Brachionus plicatilis

Insulin/insulin-like growth factor (IGF)-like signaling plays important roles in the aging processes of various animals. However, little is known about this signaling in rotifers, which have been used as a model animal in aging studies. Here we report that the aqueous extracts of the rotifer Brachionus plicatilis show activity similar to that of insulin/IGFs. Rotifers were cultured under four different feeding regimens (fed, starved for about ten days, or re-fed for 30 and 120 min after starvation), and then their aqueous extracts were added to culture media of rat L6 myoblasts. Treatment with these extracts increased the phosphorylation levels of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and two Akt substrates of approximately 48 and 60 kDa, and these phosphorylations were diminished when cells were preincubated with specific inhibitors of their upstream kinases (MAPK/ERK kinase and phosphoinositide 3-kinase, respectively). Furthermore, the extracts from fed rotifers provoked higher phosphorylation levels of MAPK/ERK and Akt substrates than the extract from starved rotifers, suggesting that the production of substance(s) with insulin/IGF-like activity is stimulated upon feeding in the rotifer.