跨入新世纪开创新局面——浙江省茶叶学会第八届理事会工作报告

1　四年工作概况本届理事会是跨世纪的一届理事会。世纪之交的 1 997～ 2 0 0 1年 ,是伟大祖国取得辉煌成就的时期 ;也是浙江茶业深化改革 ,不断开拓新局面的时期。四年来 ,本届理事会在省科协的直接领导、挂靠单位和有关部门的大力支持以及广大会员的积极参与下 ,认真分析了我省茶叶产销形势 ,认真组织并调动各方面积极性 ,克服重重困难 ,有重点、有针对性的开展了一系列活动 ,取得了新的成绩 ,为浙江茶业经济的持续发展作出了重要贡献。为此 ,我会被评为 1 997～ 1 999年度全省先进学会 ,“九五”科普先进单位 ;并再次评为“全国学会之星…     

Plitidepsin has a safe cardiac profile: a comprehensive analysis

Plitidepsin is a cyclic depsipeptide of marine origin in clinical development in cancer patients. Previously, some depsipeptides have been linked to increased cardiac toxicity. Clinical databases were searched for cardiac adverse events (CAEs) that occurred in clinical trials with the single-agent plitidepsin. Demographic, clinical and pharmacological variables were explored by univariate and multivariate logistic regression analysis. Forty-six of 578 treated patients (8.0%) had at least one CAE (11 patients (1.9%) with plitidepsin-related CAEs), none with fatal outcome as a direct consequence. The more frequent CAEs were rhythm abnormalities (n = 31; 5.4%), mostly atrial fibrillation/flutter (n = 15; 2.6%). Of note, life-threatening ventricular arrhythmias did not occur. Myocardial injury events (n = 17; 3.0%) included possible ischemic-related and non-ischemic events. Other events (miscellaneous, n = 6; 1.0%) were not related to plitidepsin. Significant associations were found with prostate or pancreas cancer primary diagnosis (p = 0.0017), known baseline cardiac risk factors (p = 0.0072), myalgia present at baseline (p = 0.0140), hemoglobin levels lower than 10 g/dL (p = 0.0208) and grade ≥2 hypokalemia (p = 0.0095). Treatment-related variables (plitidepsin dose, number of cycles, schedule and/or total cumulative dose) were not associated. Electrocardiograms performed before and after plitidepsin administration (n = 136) detected no relevant effect on QTc interval. None of the pharmacokinetic parameters analyzed had a significant impact on the probability of developing a CAE. In conclusion, the most frequent CAE type was atrial fibrillation/atrial flutter, although its frequency was not different to that reported in the age-matched healthy population, while other CAEs types were rare. No dose-cumulative pattern was observed, and no treatment-related variables were associated with CAEs. Relevant risk factors identified were related to the patient's condition and/or to disease-related characteristics rather than to drug exposure. Therefore, the current analysis supports a safe cardiac risk profile for single-agent plitidepsin in cancer patients.     

Verrucosamide,a Cytotoxic 1,4-Thiazepane-Containing Thiodepsipeptide from a Marine-Derived Actinomycete

A new cytotoxic thiodepsipeptide, verrucosamide (1), was isolated along with the known, related cyclic peptide thiocoraline, from the extract of a marine-derived actinomycete, a Verrucosispora sp., our strain CNX-026. The new peptide, which is composed of two rare seven-membered 1,4-thiazepane rings, was elucidated by a combination of spectral methods and the absolute configuration was determined by a single X-ray diffraction study. Verrucosamide (1) showed moderate cytotoxicity and selectivity in the NCI 60 cell line bioassay. The most susceptible cell lines were MDA-MB-468 breast carcinoma with an LD₅₀ of 1.26 µM, and COLO 205 colon adenocarcinoma with an LD₅₀ of 1.4 µM. Also isolated along with verrucosamide were three small 3-hydroxy(alkoxy)-quinaldic acid derivatives that appear to be products of the same biosynthetic pathway.     

Super-races are not likely to dominate a fungal population within a life time of a perennial crop plantation of cultivar mixtures: a simulation study

ABSTRACT: BACKGROUND: Deployment of cultivars with different resistance in mixtures is one means to manage plant diseases and prolong the life of resistance genes. One major concern in adopting mixtures is the development of 'super-races' that can overcome many resistance genes present in the mixture. A stochastic simulation model was developed to study the dynamics of virulence alleles in two-cultivar mixtures of perennial crops, focusing on the effects of cost of virulence and pathogen reproduction mechanism. The simulated mechanism of virulence has characteristics of both major and minor genes. RESULTS: Random genetic drift due to repeated population crashes during the overwintering phase led to fixation of a single fungal genotype (in terms of its virulence), often within 100 seasons. Overall, cost of virulence is most important in determining the virulence dynamics under the present model formulation. With cost of virulence incorporated, nearly all simulation runs ended up with a single fungal genotype that can infect only one of the two cultivars. In absence of cost of virulence, most of the simulation runs ended up with fungal genotypes that can infect both host cultivars but in many cases do not contain the maximum possible number of virulence alleles due to random drift. A minimum of 20% sexual reproduction between strains from different cultivars is necessary to ensure that the final fixed strains are able to infect both cultivars. Although the number of virulence alleles in the final genotype and the time to fixation are affected by simulation factors, most of the variability was among replicate simulation runs (i.e. stochastic in nature). The time to fixation is generally long relative to cropping cycles. CONCLUSIONS: A single fungal genotype will dominate a population due to the bottleneck in overwintering with cost of virulence primarily determining whether the dominant genotype can infect both cultivars. However, the dominate genotype is unlikely to accumulate all the virulence alleles due to genetic drift. The risk of emergence and spread of super-races is insufficiently great to prevent the use of cultivar mixtures of perennial crops as a means to reduce disease development provided that host resistance structure in mixtures is altered every cropping cycle.     

Integrating a simple shading algorithm into CERES-wheat and CERES-maize with particular regard to a changing microclimate within a relay-intercropping system

Wheat/maize related multi-cropping systems are the dominant cropping systems in North China. To improve and adjust those systems, and to study competition effects within intercropping, extended field experiments are necessary. As field experiments are time consuming, laborious and expensive, a viable alternative is the use of crop growth models that can quantify the effects of management practices on crop growth and productivity. Field experiments showed that intercropped maize yielded as high as monocropped maize, and grain yield of intercropped wheat increased by up to 32%. Based on a process-oriented modeling approach, this study focuses on analyzing and modeling competitive relationships in a wheat/maize relay intercropping system with regard to yield, solar radiation and microclimate effects. A simple shading algorithm was applied and integrated into the CERES models, which are part of the DSSAT software shell vs. 4.5. The algorithm developed estimates the proportion of shading as affected by neighbouring plant height. The model was tested to investigate the applicability of this shading algorithm within the CERES models in the simulation of grain yield and dry matter yield of wheat and maize. Model error of grain and dry matter yield for both species was below 10%. There was a tendency for grain yield to be simulated adequately but for dry matter yield to be slightly underestimated. Increased top soil temperature in intercropped wheat increased the mineralization of nitrogen and improved N supply. The wheat/maize system was N efficient. Thus, N dynamics were taken into account for simulation as well as CO₂ dynamics based upon modified wind speed. Wheat border rows were exposed to a higher wind speed until mid-June and to reduced wind speed thereafter. As a result, solar radiation, soil temperature and wind speed differed between monocropping and intercropping and could provide a starting point for simulating intercropping. Microclimate effects are often small, subtle or non-existent, while spatial and climate variability and the heterogeneity of plant populations can be considerable. Quantifying microclimatic effects may prove difficult but should not be neglected when simulating intercropping systems.     

Pollution control via a dredged pool at the inlet of a reservoir

We investigated the applicability of a dredged pool formed at the inlet of a reservoir for pollution control. To quantify the effect of a dredged pool on the water quality of a reservoir, we monitored the water quality of the Masan Reservoir, located in the city of Asan, Choongnam Province, Korea, before and after dredging. In addition, a completely mixed box model was applied to simulate the water quality of the dredged pool and reservoir. The model included a water balance equation and chemical mass balance equation, into which several interactions among water quality components, such as phytoplankton, total nitrogen (T-N), total phosphorus (T-P), dissolved oxygen, and chemical oxygen demand (COD), were incorporated. The water quality monitoring and modeling results indicated that reservoir water quality was greatly affected by the dredged pool. The loads of T-N and T-P into the reservoir were reduced by the dredged pool, which may have induced the removal of nutrients by settling. However, the dredged pool may have had a negative effect on the reservoir in terms of COD and chlorophyll-a because of the internal production of organic matter and/or algae with water detention. Therefore, a dredged pool may be used for pollution control in a reservoir, as long as it is combined with measures to reduce concentrations of organic matter and/or algae.     

Characterization of a novel serine protease inhibitor gene from a marine metagenome

A novel serine protease inhibitor (serpin) gene designated as Spi1C was cloned via the sequenced-based screening of a metagenomic library from uncultured marine microorganisms. The gene had an open reading frame of 642 base pairs, and encoded a 214-amino acid polypeptide with a predicted molecular mass of about 28.7 kDa. The deduced amino acid sequence comparison and phylogenetic analysis indicated that Spi1C and some partial proteinase inhibitor I4 serpins were closely related. Functional characterization demonstrated that the recombinant Spi1C protein could inhibit a series of serine proteases. The Spi1C protein exhibited inhibitory activity against α-chymotrypsin and trypsin with K(i) values of around 1.79 × 10(-8) and 1.52 × 10(-8) M, respectively. No inhibition activity was exhibited against elastase. Using H-d-Phe-Pip-Arg-pNA as the chromogenic substrate, the optimum pH and temperature of the inhibition activity against trypsin were 7.0-8.0 and 25 °C, respectively. The identification of a novel serpin gene underscores the potential of marine metagenome screening for novel biomolecules.     

Siphonaxanthin,a Green Algal Carotenoid,as a Novel Functional Compound

Siphonaxanthin is a specific keto-carotenoid in green algae whose bio-functional properties are yet to be identified. This review focuses on siphonaxanthin as a bioactive compound and outlines the evidence associated with functionality. Siphonaxanthin has been reported to potently inhibit the viability of human leukemia HL-60 cells via induction of apoptosis. In comparison with fucoxanthin, siphonaxanthin markedly reduced cell viability as early as 6 h after treatment. The cellular uptake of siphonaxanthin was 2-fold higher than fucoxanthin. It has been proposed that siphonaxanthin possesses significant anti-angiogenic activity in studies using human umbilical vein endothelial cells and rat aortic ring. The results of these studies suggested that the anti-angiogenic effect of siphonaxanthin is due to the down-regulation of signal transduction by fibroblast growth factor receptor-1 in vascular endothelial cells. Siphonaxanthin also exhibited inhibitory effects on antigen-induced degranulation of mast cells. These findings open up new avenues for future research on siphonaxanthin as a bioactive compound, and additional investigation, especially in vivo studies, are required to validate these findings. In addition, further studies are needed to determine its bioavailability and metabolic fate.     

Optimal gate operation of a main drainage canal in a flat,low-lying,agricultural area using a tank model

Chiyoda basin is located in Saga Prefecture in Kyushu Island, Japan, and lies next to the tidal compartment of the Chikugo River to which the excess water in the basin is drained away. Chiyoda basin has a total area of about 1,100 ha and is a typical flat and low-lying paddy-cultivated area. The main problem in this basin is the appropriate operation of drainage structures during and after flood events in order to minimize the inundation damages for crop yield and to fulfill the irrigation requirement in the irrigation period. This paper presents a mathematical model of a drainage system in Chiyoda basin for calculating the flood inundation and optimizing the operation of gates in a main drainage canal. First, the algorithm of gate operation was simulated and the drainage model was then evaluated by comparing the simulated water levels with those observed during an actual rainfall event. The results show that the observed and simulated water levels are in good agreement, indicating that the proposed model is applicable for drainage and inundation analyses in flat, low-lying paddy-cultivated areas. Second, the optimization of gate operation was investigated by trial and error method using a stochastic rainfall time series with a return period of 30 years and the tidal conditions of spring and neap tides in the Chikugo River. Comparing a total inundation time, a total inundation area and maximum inundation depth in the paddy tanks at the upstream and the downstream ends, it was concluded that the present operation based on the gate operators’ experience was almost the optimal one, and the sooner start of opening operation and the later start of closing operation within the operationality of check gates were recommended to minimize the inundation damage. The present operation could be able to minimize the total inundation time, the total inundation area and the maximum inundation depths in paddy tanks and to meet fully both the drainage and the irrigation requirements.     

Kiamycin, a unique cytotoxic angucyclinone derivative from a marine Streptomyces sp

Kiamycin (1), a new angucyclinone derivative possessing an 1,12-epoxybenz[a]anthracene ring system, was isolated from the marine Streptomyces sp. strain M268 along with the known compounds 8-O-methyltetrangomycin (3) and 8-O-methylrabelomycin (4). Their structures were elucidated by detailed spectroscopic analysis and comparison with literature data. The new angucyclinone derivative showed inhibitory activities against the human cell lines HL-60 (leukemia), A549 (lung adenocarcinoma), and BEL-7402 (hepatoma) with inhibition rates of 68.2%, 55.9%, and 31.7%, respectively, at 100 μM. It appears to have potential as an anticancer agent with selective activity.     

Ecosystem Immunity as a Strategy for Controlling Insect Pests in a Biotic Community

Summary

Populations of insect pests sometimes increase beyond the economic threshold to become serious problems in crop production. However, their populations are usually maintained below the economic injury level by natural predator insects and parasites. Living bodies often develop a degree of immunity against pest invasion, such as macrophages in the human body. In this case, macrophages reproduce in the human body at the expense of blood and body fluid, but are suppressed below the level of illness to the human body. This is analogous to crops, which have developed defense mechanism in the biotic community against pests by means of natural enemies and provided immunity in a total system. However, natural enemies, parasites and predators, must be maintained themselves with little compensation or support from the agroecosystem. Some years ago I proposed a model “reproduction curve with two equilibrium points” to describe the fluctuation of insect populations (Takahashi, 1964). The lower equilibrium point in the model can be regarded as a latent period and the higher one as the outbreak level. This model is based on the S-shaped functional response curve of predator to prey density and is applicable in a biotic community where polyphagous predators predominate. To ensure stable populations of natural enemies in the biotic community, it is necessary to maintain their food supply in the field. The populations of monopha-gous predators, such as parasitoids, fluctuate in response to prey or host populations sometimes inducing dramatic increases in pest populations above the economic injury level. On the other hand, polyphagous predators can utilize ordinary organisms as alternate food sources and keep their population stable even when a pest population (i.e., their target food) decreases to low level. This model will be discussed with respect to the diversity of a biotic community.     

水稻中的磷转运蛋白基因在异源表达系统中的功能分析

为了更好地研究植物在磷素吸收过程中的分子机制以及生物化学过程的变化,将水稻中分离得到的一个磷转运蛋白基因（OsPT6）用于互补实验。互补实验结果表明,OsPT6能够与缺失磷转运功能的酵母突变体实现互补,并在低磷条件下促进酵母突变体对磷的吸收。进一步分析表明OsPT6属于水稻Pht1家族运输蛋白基因,所编码的蛋白对磷酸盐（Pi）的吸收Km值为96 μmol/L,属于高亲和的磷转运蛋白。不同的酵母转化子对不同pH环境的响应实验显示,OsPT6是一个与质子相偶联的磷运输蛋白,其吸收磷素的最佳pH为6.0。对OsPT6在人的胚胎肾细胞（HEK293）中的表达分析表明,该基因能够编码蛋白并定位于细胞膜,证明OsPT6的功能与酵母磷转运子PHO84相似,是一个定位于细胞膜上的具有吸收转运磷素作用的运输蛋白。     

Rode Eersteling: a false name for a well-known tuber colour mutant

Summary It is shown that the monectochimeraRote Holl?ndische Erstling used in Klopfer's chimera experiments does not correspond with the present homohistic Dutch potato varietyRode Eersteling. The latter seems to be identical with Klopfer's homohisticErstling Rouge.⁴ This misapprehension is caused mainly by replacing the original monectochimerical varietyRode Eersteling in 1942 by a homohistic red sport, derived from it, without changing the variety name.     

对一起违法经营大麦种子案件处罚的探讨

20 0 4年 8月 31日 ,接群众举报 ,反映射阳县某种业经营部经营的大麦种涉嫌假冒。射阳县农业行政执法大队随即派员前往调查。经查 ,该经营部经营的“新啤 2号”大麦种 ,包装上标注的生产单位为 :盐城市某农场 ,经销商为 :盐城某种业有限公司 ,品种说明中介绍为 ,品种来源为 :江苏某农场开发有限公司和盐城市某种业有限公司对俗名“趴地虎”大麦进行穗选改良、提纯复壮后选育而成。当事人于 2 0 0 4年 8月 30日从盐城市某种业有限公司购进该批种子 9375kg ,至检查时尚未销售。执法人员进行了询问笔录 ,随机抽取了样品 ,并当场扣押了该批种子…     

Value of a tomato byproduct as a source of dietary fiber in rats

A residue consisting of tomato peel and seeds is a byproduct of thetomato paste industry. This product had, after drying and grinding,101.4 g water, 175.6 g protein, 95.9 g lipids, 36.4 g ash and590.7 g total carbohydrates per kilogram of residue. The carbohydratesin the residue were mainly dietary fiber (495.3 g) from which 405.4 gwere insoluble fiber. Additionally, the residue had ascorbic acid 0.25 g, P 3 g, Ca 1.7 g, K 13.1 g, Mg 2.4 g, Cu 0.013 g, Fe0.248 g, Mn 0.018 g and Zn 0.174 g per kilogram of residue. Theresidue fed to rats at increasing concentrations in the diet (0, 134, 263and 387 g/kg diet) over 18 days had no effect on body weight gain;caused an increase in food intake and slightly reduced feed efficiency.Incorporation of the residue in the diet caused a substantialincrease in fecal mass, which was proportional to the dietary fiber providedby the residue (r = 0.89); apparent absorption of protein, energy,Ca, Mg, Fe, Zn and Cu present in the diets was reduced. These reductions were proportional to the amount of dietary fiber provided by the residueand became substantial when the residue was included at 263 or 387g/kg. However, when the residue was included at 134 g/kg, little effect onthe apparent absorption of the dietary nutrients was noted. Because thisconcentration provided the rats with approximately 10 times more fiberthan that recommended for humans, one can expect that if this tomatoresidue were consumed at concentrations recommended for humans, itshould have no effect on nutrient availability. These results indicate that thistomato residue represents an attractive source of fiber, which in rats had alow apparent absorption (52–56%). In addition, it was very effective inincreasing fecal mass with no negative effects on growth performance.     

GmNLP7a inhibits soybean nodulation by interacting with GmNIN1a

Nitrogen(N) is an essential macronutrient for plant growth and productivity. Leguminous plants establish symbiotic relationships with nitrogen-fixing rhizobial bacteria to use atmospheric dinitrogen gas to meet high N demand under low-N conditions. Nodule formation and N fixation are energy-consuming processes and are inhibited by nitrate present in the environment. Previous studies in model leguminous plants characterized NIN-LIKE PROTEIN(NLP) proteins that mediate nitrate control of root nodul...     

Structure of a Rice Grain Represented by a New Three-Dimensional Visualisation Technique

Three-dimensional (3D) structures of a rice grain were visualised by means of the new 3D visualisation technique. This technique produced a virtual 3D model of a sample material by stacking a set of captured sequential section images in a personal computer (PC); thus, the internal structure of the sample material was constructed. The 3D structure of an immature rice seed, e.g. the formation of the vascular bundle, was visualised by reconstructing a virtual 3D model from sequential captured images of the cut-off face. The 3D structure of a brown rice grain, e.g. the location of the central line, was also visualised by means of reconstruction from captured images of stained sequential sections.     

Potential Chemopreventive Activity of a New Macrolide Antibiotic from a Marine-Derived Micromonospora sp

Agents capable of inducing phase II enzymes such as quinone reductase 1 (QR1) are known to have the potential of mediating cancer chemopreventive activity. As part of a program to discover novel phase II enzyme-inducing molecules, we identified a marine-derived actinomycete strain (CNJ-878) that exhibited activity with cultured Hepa 1c1c7 cells. Based on this activity, a new macrolide, juvenimicin C (1), as well as 5-O-α-l-rhamnosyltylactone (2), were isolated from the culture broth of a Micromonospora sp. Compound 1 enhanced QR1 enzyme activity and glutathione levels by two-fold with CD values of 10.1 and 27.7 μM, respectively. In addition, glutathione reductase and glutathione peroxidase activities were elevated. This is the first reported member of the macrolide class of antibiotics found to mediate these responses.     

Making Rice a Perfect Food

Abstract

Despite a significant increase in food production during the last century, world production will need to be doubled or tripled by the year 2050 to meet the needs of an expected 10 billion global population. Fortunately, a second revolution in agriculture appears to be taking place from advances in biotechnology. Worldwide in 1999, about 40 million hectares of transgenic plants were grown, and this area is expected to increase significantly for years to come. Rice (Oryza sauva L.) is the staple food of the majority of 3.5 billion people in Asia. Increases in population in the rice growing regions of Asia will require 70% more rice in 2025 than is consumed today. In addition, rice, in its milled form, is poor in essential amino acids and a range of vitamins and micronutri-ents, which creates malnutrition. With the increasing number of genes discovered in plants and other organisms, transgenic research is being utilized to improve agronomic traits of rice, such as resistance to biotic and abiotic stress, and to increase photosynthetic efficiency which collectively increase yield. Research is also moving toward improvement of grain quality traits, including amino acids, micronutrients, and vitamins. Genome sequencing and the techniques for rice transformation have been developed. Thus, collaborative efforts in genomics, transformation, and molecular breeding of rice are expected to lead to a significant contribution to global food security. In this article, we review the current status of genetic improvement of rice. Improved methods for transgene expression in rice and potential modifications that will significantly improve yield and grain quality of rice are also discussed.