Calcium/calmodulin-dependent signaling for prepenetration development in <Emphasis Type="Italic">Cochliobolus miyabeanus</Emphasis> infecting rice

Cochliobolus miyabeanus forms a specialized infection structure, an appressorium, to infect rice. Contacting a hard surface induces appressorium formation in C. miyabeanus, while the hydrophobicity of the substratum does not affect this morphogenic infection event. To determine whether the calcium/calmodulin-dependent signaling system is involved in prepenetration morphogenesis in C. miyabeanus, the effects of a calcium chelator (ethylene glycol tetraacetic acid; EGTA), phospholipase C inhibitor (neomycin), intracellular calcium channel blocker (TMB-8), calmodulin antagonists (chlorpromazine, phenoxybenzamine, and W-7), and calcineurin inhibitor (cyclosporin A) on morphogenesis and infection were examined. Addition of Ca²⁺ and the calcium ionophore A23187 did not affect conidial germination, while the number of appressoria decreased with higher concentrations. EGTA inhibited conidial germination and appressorium formation. The calcium channel blocker did not affect appressorium formation at any concentration; however, calmodulin antagonists and the calcineurin inhibitor specifically reduced appressorium formation at the micromolar level. One of the calmodulin antagonists, W-7, also inhibited accumulation of mRNA of the calmodulin gene within germinating conidia and/or appressorium-forming germ tubes. Thus, biochemical processes controlled by the calcium/calmodulin signaling system seem to be involved in the induction of prepenetration morphogenesis on rice.     

水竹林土壤条件与倒笋关系研究

本文是根据安徽省舒城县龙河口地区水竹择伐人工异龄林内15个土壤剖面39个土样分析资料和1985—1987年160块次标准地的竹笋观测数据,进行数量化分析和回归计算,拟合出40个回归方程,研究水竹林土壤条件和倒笋间关系。研究表明:1)水竹林倒笋严重程度的顺序按土壤质地为:粘壤土>砂土>砂质粘土>砂壤土>壤土,按土壤厚度为:厚土层(≥50厘米)或薄土层(≤30厘米)高于中土层(30—50厘米);②土壤含水率高,倒笋严重,毛管孔隙度为35—40％,总孔隙度为50％,倒笋少;③土壤含氮量为1.90—1.95ton/mu,含磷量为0.50—0.75 ton/mu,倒笋少,阳离子代换量与倒笋呈负相关,与钾含量相关不显著;④倒笋与氮、磷、钾三元素含量之和呈正相关;⑤氮、磷、钾、含水量、阳离子代换量、孔隙度六元素与倒笋率关系分别年度拟合出回归方程。     

Progress and prospects of community forestry in developing and developed countries

Community forestry is practiced in various countries throughout the world, with respect to both native forests and plantations, for livelihood and forest protection purposes and also for urban amenity values. While forests have been managed to some extent by communities for thousands of years, modern models of community forestry have been practiced widely for only about 30 years. Community forestry takes many forms; there is no unique definition or categorisation, although a number of characteristics are frequently present. There is in general, involvement of a local community in forest planning as well as management, for a form of forestry which is usually relatively small-scale, motivated by multiple objectives, and receiving some financial support and organisational assistance by government and non-government organisations. Where plantations are established, these may be managed as common property, individual property rights may apply, or there may be a combination of both. Analysis of the specific research studies included in this issue reveals that community forestry systems have been refined over time as experience is gained in program designs, and notable successes have been achieved. However, ‘the jury is still out’ on whether community forestry has lived up to the optimistic expectations of its proponents.     

Variation in effective number of clones in seed orchards

The effective number of clones (N _c) wasestimated for 255 conifer clonal seed orchards in Finland, Korea, andSweden, based on the variation in the number of ramets among clones. Themean census number of clones (N) varied from 70, in 13 KoreanPinus koraiensis seed orchards, to 139 in 176 Finnish Pinussylvestris seed orchards. The mean effective number of clones(N _c) was 66, with a range from 10 to 421. One fifthof the orchards had N _c between 10 and 40, and twothirds between 41 and 160. On average, the relative effective number ofclones (N _r =N _c/N) was 0.74, with a range from 0.2to almost 1.0. Thus, the census number of clones in a seed orchard isgenerally rather informative, but the effective number of clones is moreinformative. Many of these first-generation seed orchards wereestablished with an intention to have near-equal numbers of ramets foreach clone. The use of effective number of clones may be more importantin future seed orchards and genetically thinned seed orchards.     

Helicobacter apodemus sp. nov., a new Helicobacter species identified from the gastrointestinal tract of striped field mice in Korea

A novel Helicobacter species was identified from the gastrointestinal tract of the Korean striped field mouse (Apodemus agrarius). Biochemical testing, ultrastructure characterization, and 16S rRNA gene sequence analysis suggested that this bacterium represents a distinct taxon. The bacterium was positive for urease activity, susceptible to cephalothin and nalidixic acid, and weakly positive for oxidase and catalase activity. Electron microscopy revealed that the bacterium has spirally curved rod morphology with singular bipolar nonsheathed flagella. Genotypically, the isolated bacterial strains (YMRC 000215, YMRC 000216, and YMRC 000419) were most closely related to a reference strain of Helicobacter mesocricetorum (97.25%, 97.32%, and 97.03% 16S rRNA sequence similarities, respectively). The 16S rRNA sequences of these strains were deposited into GenBank under accession numbers {"type":"entrez-nucleotide","attrs":{"text":"AF284754","term_id":"18389594","term_text":"AF284754"}}AF284754, {"type":"entrez-nucleotide","attrs":{"text":"AY009129","term_id":"18409527","term_text":"AY009129"}}AY009129, and {"type":"entrez-nucleotide","attrs":{"text":"AY009130","term_id":"18409528","term_text":"AY009130"}}AY009130, respectively. We propose the name Helicobacter apodemus for this novel species.     

The effects of administering estradiol benzoate plus progesterone during the growth or static phases of the dominant follicle in CIDR-treated lactating dairy cows

We studied the effects of administering estradiol benzoate (EB) plus progesterone (P4) as part of a CIDR-based protocol during the growth or static phases of dominant follicle development on follicular wave emergence, follicular growth, synchrony of ovulation and pregnancy rate following CIDR withdrawal, treatment with PGF(2alpha) and GnRH, and fixed-time artificial insemination (TAI). Forty-one previously synchronized lactating Holstein dairy cows were randomly allocated to three treatment groups. The control group (n=14) received a CIDR on the third day after ovulation only (Day 0). The two treatment groups were administered CIDRs comprising 2 mg EB and 50 mg P4 either on the third (T1, n=14) or eighth day (T2, n=13) after ovulation (Day 0). All cows received PGF(2alpha) after CIDR removal on Day 7, GnRH on Day 9, and TAI 16 h after GnRH treatment. The proportion of cows with follicular wave emergence within 8 days of treatment differed (P<0.01) among the control (14.3%), T1 (85.7%), and T2 groups (92.9%). However, the mean intervals between treatment and wave emergence were not significantly different. There were significant differences in the diameters of the dominant follicles on Day 7 (P<0.01) and in preovulatory follicles on Day 9 (P<0.01), with the largest follicles observed in the control group and the smallest follicles observed in the T2 group. In contrast, the numbers of cows showing synchronous ovulation after GnRH treatment (92.9 to 100.0%) and pregnancy following TAI (46.2 to 50.0%) were similar between the treatment groups. The results showed that, irrespective of the phase (growth or static) of the dominant follicle, administration of 2 mg EB plus 50 mg P4 to CIDR-treated lactating dairy cows induced consistent follicular wave emergence and development, synchronous ovulation after GnRH administration, and similar pregnancy rates following TAI.     

Notes on psyllids (Hemiptera: Psylloidea) intercepted on imported cut flowers and branches in South Korea 2014–2018

A total of 10 species of psyllids from 8 different countries were intercepted by plant health inspectors in South Korea on consignments of fresh cut flowers (and branches for use in flower arrangements) at the ports of entry in South Korea from 2014 to 2018. Of the 10 species that were intercepted, some species are potential pests that could enter and establish in Korea through the import of these flowers and branches. Current information on intercepted psyllids is required to alert plant health inspectors to look carefully at cut flowers to prevent the introduction of non-indigenous species.     

Impact of inland waters on highly pathogenic avian influenza outbreaks in neighboring poultry farms in South Korea

BackgroundSince 2003, the H5 highly pathogenic avian influenza (HPAI) subtype has caused massive economic losses in the poultry industry in South Korea. The role of inland water bodies in avian influenza (AI) outbreaks has not been investigated. Identifying water bodies that facilitate risk pathways leading to the incursion of the HPAI virus (HPAIV) into poultry farms is essential for implementing specific precautionary measures to prevent viral transmission.ObjectivesThis matched case-control study (1:4) examined whether inland waters were associated with a higher risk of AI outbreaks in the neighboring poultry farms.MethodsRivers, irrigation canals, lakes, and ponds were considered inland water bodies. The cases and controls were chosen based on the matching criteria. The nearest possible farms located within a radius of 3 km of the case farms were chosen as the control farms. The poultry farms were selected randomly, and two HPAI epidemics (H5N8 [2014–2016] and H5N6 [2016–2017]) were studied. Conditional logistic regression analysis was applied.ResultsStatistical analysis revealed that inland waters near poultry farms were significant risk factors for AI outbreaks. The study speculated that freely wandering wild waterfowl and small animals contaminate areas surrounding poultry farms.ConclusionsPet birds and animals raised alongside poultry birds on farm premises may wander easily to nearby waters, potentially increasing the risk of AI infection in poultry farms. Mechanical transmission of the AI virus occurs when poultry farm workers or visitors come into contact with infected water bodies or their surroundings. To prevent AI outbreaks in the future, poultry farms should adopt strict precautions to avoid contact with nearby water bodies and their surroundings.     

3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid, an active principle of kimchi, inhibits development of atherosclerosis in rabbits

The effects of 3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid (HDMPPA) originating from Korean cabbage kimchi were investigated, showing an antioxidant effect on the prevention of atherosclerosis in hypercholesterolemic rabbits. Twenty-one 3-month-old rabbits were fed an atherogenic diet containing 0.5% (w/w) cholesterol and 10% (w/w) coconut oil, whereas another two groups were given an atherogenic diet with intravenous injection of either HDMPPA or simvastatin (0.33 mg/kg/day) for 4 weeks. HDMPPA inhibited the oxidative modification of low-density lipoprotein (IC 50 = 1.4 microg/mL) and increased 2,2'-diphenyl-1-picrylhydrazyl radical scavenging activity (IC 50 = 0.78 microg/mL) in a dose-dependent manner. In hypercholesterolemic rabbits, the thickness of intima of aorta of the HDMPPA group was significantly reduced (control versus HDMPPA, 42%; simvastatin, 38%) without a plasma cholesterol-lowering effect. Thiobarbituric acid reactive substance formation in the plasma of the HDMPPA group was significantly decreased compared to that of the control group. Furthermore, the generation of vascular reactive oxygen species in HDMPPA group was suppressed as the cyclooxygenase-2 protein level decreased. These findings suggest that HDMPPA prevents the development of aortic atherosclerosis in high-cholesterol-fed rabbits. The antiatherosclerotic effect of HDMPPA may be due to an antioxidative effect at a low dose without cholesterol-lowering effects.