马铃薯晚疫病流行学及防治方法研究进展   总被引：13，自引：3，他引：13  

曹静  客绍英 《中国马铃薯》2005,19(1):33-36

马铃薯晚疫病流行性强,危害严重,是限制马铃薯生产的主要病害之一。针对目前生产上该病害防治困难的现状,本文综述了马铃薯晚疫病流行学和防治方法的研究进展,并对今后的研究提出了建议。  相似文献   

外源添加物降低镉胁迫下香菇体内镉含量及对酶活性的影响   总被引：1，自引：0，他引：1  

杨晖  赵鹂  张龙  梁巧玲  柯乐芹 《核农学报》2015,29(1):183-191

香菇等可食用菇类比绿色植物体内更能逐步聚集浓度大的镉等重金属。子实体中的镉危及食用者的健康,因此减少菇类子实体中镉的含量,对人体健康意义重大。本研究检测了5种外源添加物水杨酸、沸石、石膏、壳聚糖及硫酸锌对镉胁迫下香菇体内镉含量的降低作用,并测定不同添加物对香菇羧甲基纤维素酶和漆酶活性的影响。试验结果表明,被测试的添加物中,硫酸锌对香菇808和868子实体中的镉含量著,石膏次之,表明硫酸锌是5种外源添加物中降低香菇体内镉浓度的最佳选择。此外,通过测定5种外源添加物在3 mg·kg-1镉胁迫下对香菇羧甲基纤维素酶和漆酶活性的影响,试验数据表明菌丝满袋期时,在添加硫酸锌或石膏时,香菇羧甲基纤维素酶和漆酶活性达到最高,说明培养料中添加硫酸锌或石膏在降低香菇体内镉含量的同时,也可以一定程度上增强生长代谢酶的活性。  相似文献   

安庆市宜秀区现代农业发展现状与对策     

柯冬芹 《安徽农业科学》2015,(8):264-266

近年来,安庆市宜秀区大力实施“产业富民”发展战略,充分发挥区位优势和资源优势,为现代农业的发展奠定了坚实的基础.该研究基于现代农业的内涵,分析了宜秀区现代农业发展的现状及存在的问题,提出了宜秀区现代农业发展的思路与对策,以实现农业发展、农村繁荣、农民增收的目标,打造“宜游宜秀”.  相似文献   

不同浓度有机水溶肥对热带设施甜瓜产量和品质的影响     

柯用春  曹明  杨小锋  任红  黄植  王育瑞  陈广旺  林福  许江伟 《新疆农业科学》2015,(2):217-221

【目的】研究叶面施肥对热带设施甜瓜产量及品质影响,探讨甜瓜有机水溶肥叶面施肥的应用效果,为热带设施甜瓜叶面肥的推广提供理论与实践依据。【方法】设计肥料浓度4种水平组合,以清水为对照,研究有机水溶肥料不同浓度对热带设施栽培甜瓜生长发育、产量和品质的影响。【结果】喷施有机水溶肥料的处理各次观测的叶片面积较对照高16.56%、18.36%和7.38%。叶片SPAD值平均较对照分别提高了13.75%、14.98%和13.70%。甜瓜纵横径增加,纵径分别提高6.75%、14.53%、15.88%和16.65%,横径分别提高3.28%、7.12%、9.33%和9.47%。随着用量的增加,产量也呈增加趋势,增产比例分别为9.01%、26.44%、28.50%、31.02%。【结论】不同浓度水溶肥料叶面喷施对热带设施甜瓜产量和品质有明显影响,采用伸蔓期200 ml/(667 m2·次),其它时期250 ml/(667 m2·次)的喷施方法可显著提高产量,提升品质。  相似文献   

中国股票市场理论价值定位探讨     

柯原 《福建农业大学学报(哲学社会科学版)》2005,8(3):40-44

回顾了中国证券市场理论估值的研究,发现用平均市盈率进行国际比较对股票市场估值有较大缺陷.认为一个国家股票市场的理论价值定位必须考虑一国的利率、经济增长率、国家风险等.本文运用两元增长模型加入国家风险对中国股票市场进行理论估值探讨,认为中国股票市场目前的估值合理,具备投资价值.  相似文献   

Immunogenicity of a temperature sensitive mutant Mycoplasma gaffisepticum vaccine     

KG WHITHEAR  SOERIPTO  KE HARRIGAN †  E GHIOCAS 《Australian veterinary journal》1990,67(5):168-174

The immunogenicity of the ts-11 vaccine strain of Mycoplasma gallisepticum was assessed following eye drop or coarse aerosol administration in chickens of various ages. Protection was evalualted following intra-abdominal (IA) or fine droplet aerosol administration of virulent M. gallisepticum, usually the Ap3AS strain and was measured mainly by the scoring of gross air sac lesions or by egg production. Vaccination of chickens with ts-11 did not elicit a substantial serum antibody response as measured by rapid serum agglutination test, or ELISA. Protection was never demonstrated when no M. gallisepticum serum antibody response was detected in a vaccinated group of chickens. Failure to protect occurred usually, although not invariably, following aerosol administration of the vaccine. Vaccination by eye drop usually, although not invariably provided protection against challenge. In one experiment, chickens vaccinated by eye drop at 8-weeks were as susceptible as non vaccinated controls when challenged by IA inoculation at 13-weeks-of-age. Yet other birds from the same vaccinated group were resistant when challenged in an identical way at 23-weeks. No measurable increase in M. gallisepticum specific serum antibody concentrations occurred in the intervening period. Equally surprising was the response of another group of birds in the same experiment that had been vaccinated with a higher dose of ts-11. An antibody response was detected in this group, but they were susceptible to challenge at 23-weeks. Interestingly, a drop in egg production commenced 4 weeks after challenge, 2 weeks later than that observed in a non vaccinated group challenged at the same time.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Pine needle abortion in cattle: a review and report of 1973-1984 research   总被引：1，自引：0，他引：1  

L F James  R E Short  K E Panter  R J Molyneux  L D Stuart  R A Bellows 《The Cornell veterinarian》1989,79(1):39-52

Research has verified field observations that cows grazing ponderosa pine needles may abort. The incidence and nature of the abortions produced experimentally simulate very closely those reported by livestock producers and veterinarians. The incidence of experimentally-produced abortions varied markedly from year to year even though the needles were collected in the same general area each year. This suggests that the abortifacient compound(s) in the needles vary from year to year, probably due to environmental and site conditions. The impact of stress (cold and nutrition) as a factor in the abortions was examined. It was concluded that the only effects would be on the willingness of cows to eat the needles. The pine needle abortion problem, what is known of the etiology, and mechanisms of the abortion are reviewed. The usefulness of bioassay systems to study pine needle abortions is discussed.  相似文献   

Toxicosis in pigs fed selenium-accumulating Astragalus plant species or sodium selenate     

D C Baker  L F James  W J Hartley  K E Panter  H F Maynard  J Pfister 《American journal of veterinary research》1989,50(8):1396-1399

Three groups of 5 pigs each were fed a high selenium (Se) diet by mixing either Astragalus praelongus (31.6 ppm Se in feed), A bisulcatus (31.7 ppm Se in feed), or sodium selenate (26.6 ppm Se in feed) with commercial hog feed. Ten control pigs were fed only commercial hog chow containing trace selenium (0.44 ppm Se). Pigs were fed for 9 weeks and necropsied when they had ataxia or paralysis. Blood was collected for hematologic and serum biochemical determinations, and samples of various tissues were collected and fixed in neutral-buffered 10% formalin for histologic evaluation or frozen for determination of selenium concentration. All forms of selenium induced clinical signs of weight and hair loss, with cracked hooves and inflamed coronary bands developing in all Na2SeO4-fed pigs and 1 A praelongus-fed pig, but not in A bisulcatus-fed pigs. Serum calcium, phosphorus, and albumin concentrations were unchanged or significantly decreased from prefeeding values in groups fed selenium. Serum aspartate transaminase (AST) activities in Astragalus species-fed groups, and amylase activities and PCV in all groups of pigs fed selenium, were increased. Serum alkaline phosphatase and creatine kinase activities were significantly increased in the A praelongus-fed pigs and significantly decreased in Na2SeO4-fed pigs. Terminal tissue and body fluid selenium concentrations were determined in all groups of pigs fed selenium and compared with values in control pigs. Urine and bile concentrations were increased by the greatest factor (40 to 100x), with tissue concentrations of selenium increased by a lesser factor (6 to 17x).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Ultrasonographic imaging to monitor fetal and placental developments in ewes fed locoweed (Astragalus lentiginosus)   总被引：1，自引：0，他引：1  

K E Panter  T D Bunch  L F James  D V Sisson 《American journal of veterinary research》1987,48(4):686-690

Ultrasonographic imaging was used to monitor the effects of locoweed (Astragalus lentiginosus) on fetal, placental, and cotyledonary developments in pregnant ewes and proved to be a useful noninvasive method of monitoring the effects of locoweed poisoning on fetal and placental development. Ultrasonographic imaging may be a good research technique to observe the effects of toxicants on fetal movement, fetal heart action, and growth and development of the fetus and placenta. Known effects of locoweed poisoning in pregnant ewes, such as fluid accumulation in the placenta (hydrops allantois, hydrops amnii), altered cotyledonary development, and fetal death were observed with ultrasonographic imaging. A previously unknown effect of locoweed on fetal heart action also was observed. Locoweed decreased fetal heart rates, caused cardiac irregularity, and decreased the strength of heart contractions. All ewes, except No. 3525, fed locoweed aborted. At necropsy, aborted fetuses had hypertrophy of the heart, right ventricular dilatation, rounded at the apex of the heart, and generalized edema.  相似文献   

Ponderosa pine needle-induced parturition in cattle.     

K E Panter  L F James  R J Molyneux 《Journal of animal science》1992,70(5):1604-1608

Needles of the Ponderosa pine (Pinus ponderosa) induce premature parturition in cattle when ingested during late pregnancy, especially during the third trimester. The closer to term, the more likely that pine needles will induce parturition. Experiments were designed to describe the clinical signs and behavior associated with ingestion of pine needles. Pine needles adversely affected only pregnant cows and did not seem to affect nonpregnant, cycling cows, sheep, goats, or rabbits. Premature parturition was more likely if cows ingested the needles after the 8th mo of pregnancy, if they ingested pine needles over a period of 3 d or more, and if cows ate a relatively large amount of pine needles (about 2.2 to 2.7 kg/d). A synthetic progesterone, melangesterol acetate, and a prostaglandin inhibitor (ketoprofen) seemed to be of some prophylactic benefit; however, further research is required to assess the practicality of the approach and the magnitude of the benefit. Ponderosa pine bark and new-growth branch tips, which seem to be more potent inducers of premature parturition, may be useful in the extraction and identification of the parturifacient component(s).  相似文献