Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production

Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic antibiotics have been applied during the grafting practice. However, the use of such antibiotics presents a number of problems associated with their incomplete biodegradability, limited efficacy in some cases, and an increased risk of selecting for antimicrobial resistant bacteria. We investigated the application of a marine antimicrobial peptide, tachyplesin, which is present in the Japanese horseshoe crab Tachypleus tridentatus, in combination with two marine bacterial exopolymers as alternative treatment agents. In field studies, the combination treatment resulted in a significant reduction in graft failures vs. untreated controls. The combination of tachyplesin (73 mg/L) with two bacterial exopolysaccharides (0.5% w/w) acting as filming agents, reduces graft-associated bacterial contamination. The survival data were similar to that reported for antibiotic treatments. These data suggest that non-antibiotic treatments of pearl oysters may provide an effective means of improving oyster survival following grafting procedures.     

中国天然橡胶生产的生产函数分析

为了稳定和提高天然橡胶产量,保证中国战略物资的安全,分析了年均开割面积、年末从业人员数、化肥施用量、硫磺粉施用量、乙烯利施用量、天然橡胶固定资产投资额、全年开割天数等影响天然橡胶生产的主要因素。应用计量经济学的方法构建了天然橡胶的生产函数模型,用该模型比较了近15年来各因素对天然橡胶产量的贡献率。结果表明：年均开割面积和全年开割天数是天然橡胶增产最主要的贡献因素。     

The Use of Allelopathic Studies in the Search for Natural Herbicides

Summary

The use of herbicides is claimed to negatively affect the environment and actually it does not represent an appropriate tool for the control of some weeds developing resistance. Allelopathic studies offer a challenge for discovering new lead compounds with new target sites. Then, they might be able to control the actual resistant weeds. A Standard Bioassay with selected Standard Target Species (belonging to both monocotyledonous and dicotyledonous species) is proposed to overcome the low reproducibility and the difficulties in comparing results from different research groups. This bioassay includes a commercial herbicide of known levels of activity. Herein, we illustrate this procedure with the results of studies performed with different plants belonging to wild and agricultural ecosystems that have rendered many allelochemicals belonging mainly to several terpene families.     

绿色有机水稻生产技术要点

绿色有机水稻不仅对人类的身体健康有益,而且具有良好的经济效益。本文分别从水稻生产的转换期、育苗材料的选择、本田管理等方面总结了绿色水稻生产的技术要点。     

天然茶咖啡碱工业化生产技术研制成功

咖啡碱,又名咖啡因,化学名为１,３,７－三甲基黄嘌呤,是一种重要的食品添加剂和药用原料。目前市场上的产品多属化学合成品,不符合人们追求自然的要求,加上合成产品中含有不易除去的中间合成产物,因此国内外市场对天然咖啡碱的需求趋旺。茶叶中的咖啡碱是其主要成...     

自然低温环境胁迫单株选择法及其在广占63S原种生产中的应用

利用正季自然低温条件的环境胁迫作用,建立了水稻光温敏核不育系广占63S核心单株筛选及原种生产的技术体系,该体系具有方法简便、适宜大量繁殖原原种的特点.实践表明,此方法可用于防止光温敏不育系不育起点温度向上漂移的问题,是选择核心单株的新途径.     

我国天然橡胶生产潜力分析

根据现有资料,结合作者对海南、云南和广东三大天然橡胶主产区的调研结果,从可拓展面积、割胶技术、栽培技术、品种改良、管理方式、政策支持等方面对我国天然橡胶的生产潜力进行了较系统的分析。     

浦城县绿色食品水稻标准化生产技术

南平市浦城县于2014年申请创建全国绿色食品原料(水稻)标准化生产基地,该基地于2019年通过验收。总结了浦城县从选择土壤灌溉水洁净度高的农田,使用绿色食品生产资料、化学投入品减量化配比和生态栽培等关键环节运用绿色食品标准的经验做法。     

The Suppression of Verticillium Wilt of Potato Using Corn as a Green Manure Crop

Field studies involving the effects of growing sweet corn (Zea mays var. Jubilee sweet corn and var. Jubilee super-sweet corn) as a green manure for 2 or 3 seasons demonstrated both suppression of verticillium wilt by 60–70% (Verticillium dahliae Kleb.) and increased potato yields. Although these treatments showed no direct effect on V. dahliae soil populations, the colonization of V. dahliae on potato feeder-roots and in potato tissue of stem apices were reduced. Feeder-root colonization by V. dahliae was positively correlated with verticillium wilt incidence (P?≤?0.05 to P?≤?0.01) and negatively correlated with yield (P?≤?0.05). Corn green manures additionally increased populations of several soilborne fungi which included Ulocladium, and Fusarium equiseti. Specific nutritional and microbial effects were secondary to the effects of cropping practices. When compared with the fallow treatments for 1994, 1995, and 1997, the percentage yield increases for 1994 were: +34% for total yield, +57% for U.S. #1’s, and +127% for tubers >280 g; for 1995 (a year of reduced degree-days and decreased verticillium incidence): +14% for total yields, +15% for U.S. #1 yields, and +21% for tubers >280 g; for 1997: +24% for yield totals, +74% for U.S. #1’s and +179% for tubers >280 g. For establishing these yield benefits, stalks with and without ears of corn were used as green manures. Corn varieties differed for effectiveness as a green manure, which could be accounted for by differences of biomass. When compared with the super-sweet corn, the sweet corn produced an increase (>2-fold) of biomass with less than half of the resulting wilt incidence. When potato was grown consecutively for 2 years, the benefits from green manures became mostly eliminated. However, following 2 consecutive years of potato, a single green manure of sweet corn was sufficient to return the potato crop to the original benefits of verticillium suppression and increased yields. This occurred even though soilborne V. dahliae inoculum levels had increased by >4-fold from 45 to 182 cfu g^?1 of soil. Results of this study demonstrate the importance of green manures and soil-ecology to the management of the Russet Burbank potato.     

促进剂TBSI/ZDiBC并用对天然胶乳及其胶膜性能的影响

N-叔丁基-双(2-苯并噻唑)次磺酰亚胺(TBSI)为硫化平坦性宽、硫化胶强度高、但硫化速度较慢的环保型促进剂,二异丁基二硫代氨基甲酸锌(ZDi BC)是超速级的低亚硝胺环保型促进剂,因此将两者组成活化的并用体系时,不仅降低了胶乳制品中的N-亚硝胺含量,而且缩短了正硫化时间,硫化曲线平坦,进一步提高了硫化胶力学性能。本研究以TBSI/ZDi BC为促进剂,采用硫磺硫化体系,考察了促进剂TBSI/ZDi BC的并用比例、贮存时间对天然胶乳胶体性能、胶膜硫化特性、力学性能的影响,同时考察了硫化温度对天然胶乳配合胶膜硫化特性及力学性能的影响。结果表明:增大促进剂TBSI/ZDi BC中TBSI的用量,配合胶乳机械稳定性(MST)降低,热稳定性(HST)和粘度增大;随贮存时间的延长,配合胶乳机械稳定性(MST)呈先稍下降后上升,最后又下降的趋势,热稳定性(HST)先升后降,粘度变化不大;促进剂TBSI/ZDi BC并用具有协同作用,且并用比为1∶2时,硫化胶综合性能最佳;硫化温度提高,硫化速率增大,定伸应力、拉伸强度、撕裂强度都呈先升后降的趋势。     

稻田养蟹绿色生产技术规程

为合理有效利用土地、灌溉水、温光等资源,提高水稻、河蟹的产量及品质,减少化肥农药对稻谷、河蟹及周边环境的污染,按照绿色食品生产的相关规定,结合辽宁滨海稻区稻田养蟹的现状,在深入调研及专家组评审的基础上,制定了《稻田养蟹绿色生产技术规程》。从前期准备、工程建设、水稻生产技术、河蟹养殖技术等方面提出了稻田养蟹的相关要求。     

播种方式和栽插密度对毯苗机插水稻南粳9108产量及光合物质生产的影响

以南粳9108为试验材料,在印刷播种和常规播种方式下,探讨不同栽插密度对毯苗机插水稻产量及其光合物质生产特征的影响。结果表明,与常规播种相比,印刷播种方式下水稻增产1.9%~6.3%,差异显著;长生育期、大群体颖花量和高干物质积累量是印刷播种方式水稻增产的重要途径;适当降低栽插密度可使印刷播种方式毯苗机插水稻获得高产,行株距30.0 cm×13.0 cm是印刷播种方式水稻获得高产的较优配置。     

The Use of True Potato Seed as Pro-poor Technology: The Efforts of an International Agricultural Research Institute to Innovating Potato Production

The International Potato Center (CIP) and collaborating institutions implemented an intensive research programme over a period of 25–30 years on the use of botanical seed of potato as an alternative way of growing a potato crop. The use of botanical or ‘true’ potato seed (TPS) had many advantages over the use of seed tubers. Potentially, the use of TPS was especially attractive for small-scale farmers in developing countries. The difference of using TPS as compared to using seed tubers meant in many respects the development of a new crop–commodity chain, requiring research on breeding, seed production, agronomy and marketing aspects. This research made it possible to produce potatoes from TPS at commercial scale: it removed a number of important constraints in the uniformity and earliness of the TPS varieties and in seed physiology. Experimentation and adoption by farmers in a wide range of countries showed that the technological advantages of using TPS were only translating in economical benefits as compared to tuber seed when the last one was costly or not available. Since the economic performance of seed tubers is likely to continue to fluctuate, TPS remains an interesting alternative. Study of the use of TPS in various countries could contribute to better understanding of factors that promote or inhibit crop technology innovation. The article gives an overview of the various areas of TPS research in CIP and presents information on the application of TPS technology in several developing countries.     

钾肥在马铃薯上的肥效试验研究

半干旱地区在常规施肥基础上增施钾肥具有显著的增产增效作用 ,以施 6 0～ 90kg/hm2的K2 O效果较好 ,较无肥对照增产 75 4 9 5～ 94 0 0 5kg/hm2 ,净增产值 30 4 5 0 5～ 386 2 5 5元 /hm2 ,较单施氮、磷肥对照增产 2 799 0～ 4 6 5 0 0kg/hm2 ,净增产值 1183 5～ 2 0 0 1 0元 /hm2 ,使马铃薯商品薯率提高 0 1%～ 5 3%。     

促腐农家肥对马铃薯产量影响研究初报

施用HM发酵促腐农家肥能有效促进马铃薯早生快发,提高了马铃薯产量。其中鸡粪促腐有机肥产量最高,667m2为1971.9kg,比CK增产49.14%;猪肥促腐有机肥产量为1877.0kg,位居第二,比CK增产41.92%;牛羊粪促腐有机肥产量为1870.6kg,排位第三,比CK增产41.47%,促腐有机肥各处理均比CK增产均达极显著水平。     

Nematodes as a Limiting Factor in Potato Production in Scandinavia

Plant parasitic nematodes associated with potato feed on roots and/or tubers. About 70 species, representing 24 genera, have been reported from potato. Since nematodes attack underground plant parts, there are no reliable foliar symptoms to show that nematodes may be the major cause of poor growth and reduced tuber yields. Potato roots damaged by nematodes may show lesions, abnormal proliferation of lateral roots, emerging white females and brown cysts. Nematode attacks may render plants vulnerable to other pathogens, so disease caused by microorganisms may have nematodes as an etiological component. Therefore, nematode damage may often have been attributed to other factors. In Scandinavia, potato cyst nematodes (Globodera rostochiensis and Globodera pallida) are by far the most important nematodes on potato. In Norway, the cost of compensations schemes due to imposed statutory regulations of potato cyst nematodes may some years exceed the compensation for any other pests or diseases organism in agriculture. Other important nematodes include root lesion nematodes (Pratylenchus spp.), stubby root nematodes (Trichodorus spp. and Paratrichodorus spp.), and potato rot and stem nematodes (Ditylenchus spp.). Root knot nematode Meloidogyne hapla is considered less important. Meloidogyne chitwoodi and Meloidogyne fallax are not known to be present in Nordic countries. In the control, crop rotations using non-host crops, alternating susceptible and resistant potato cultivars, are an important control measure. However, the use of resistant potato cultivars requires knowledge of the species and pathotypes present in the field.     

基于GIS的河南省小麦自然生产优势区域评价研究

为了直观显示河南省小麦生产优势区域的分布状况,给自然资源合理开发提供指导,在作物生产潜力研究的基础上,利用地理信息系统(GIS)建立了河南省小麦生产空间数据库和属性数据库。采用机制法通过对光、温、水、土逐级衰减计算了河南省各县市小麦的光、温、水、土自然生产潜力。结果表明,河南省小麦生产光能潜力在22 241~29 150 kg.ha-1之间,并从东北至西南逐渐变小;光温潜力值在11 501~15774kg.ha-1之间,东北部、中部以及南部值较大,西部山区潜力值最小;气候生产潜力值在8 262~15 349 kg.ha-1之间,空间分布趋势是南部较高,东部、中部的部分县市以及西部较低;土地生产潜力全省位于2 612~14551 kg.ha-1之间,北部和中东部的部分县市潜力值较高,西部的绝大部分潜力值最低。     

湖南安乡棉区棉花生产绿色发展之我见

通过对湖南安乡棉区棉花生产效益和生产模式的分析,以及棉花生产对环境影响的分析,提出了从肥料和农药投入、棉秆还田、棉田用养结合、实现彩棉生产等方面发展棉花产业链,搞活棉业经济、改善环境,以适应现代农业可持续性发展的需要。     

马铃薯脱毒试管薯工厂化生产技术及应用研究

研究明确了2倍MS培养基培育健壮母株是提高试管薯的结薯率和单薯重的基础。不同激素与配比对试管薯诱导的效果有很大差异,明确了BA是诱导试管薯的重要激素之一。利用试管薯繁殖原原种较试管苗直接移栽,显著提高了单株块茎数和产量。试验结果证明,直接利用试管薯有利于工厂化生产和原原种的繁殖。     

蒸青绿茶安全生产管理及质量追溯系统的构建与实现①

以广东华海糖业发展有限公司“ 雄鸥牌”蒸青绿茶的生产为实证,通过分析蒸青绿茶生产工艺流程。构建了绿茶质量安全可追溯系统,建立完善的产品质量追溯管理制度,实现茶叶生产企业的安全生产管理,并为消费者提供质量追溯查询信息。