大豆田苣荬菜综合防除技术研究

提出了大豆田恶性杂草—苣荬菜的综合防除技术体系：１）降低大豆在整个轮作体系中的比例，将苣荬菜消灭于禾谷类作物四；２）深翻抑制芽根的萌发；３）大豆前茬作物收获后秋季茎叶处理２．４－Ｄ丁酯，最佳用药量为０．８１～１．３５ｋｇ／ｈｍ２，最佳施药时期为１０月５～１０日；４）作为挽救措施可在大豆播后苗前施２．４—Ｄ丁酯，用药量为０．７２ｋｇ／ｈｍ２，并可与乙草胺、赛克津等常规大豆田除草剂混用．     

桃需冷量遗传特性的研究

对桃的９个杂交组合４６３株杂种实生苗需冷量进行测定,统计结果表明：桃需冷量是由多基因控制的,Ｆ＿１需冷量平均值较亲中值短,不同组合偏离程度不同,南山甜桃、红日、玛丽维拉、白凤、大久保需冷量育种值分别为１５９、２１６、３１９、８３１、８３４ｈ,遗传传递力分别为７９%、５４%、９２%、８３%、９３%。需冷量的遗传力为８９．６９%。萌芽开花与需冷量密切相关。     

大肠杆菌耐热性肠毒素ST1—K99／LacZ基因重组的研究

将构建的ｐＢＳＴ２～６工程菌质粒用限制性内切酶ＢａｍＨＩ／ＢｇｌⅡ酶切，经琼脂糖凝胶电泳和电洗脱，回收１４７ｂｐ的目的ＳＴ１基因。随之将该基因分别重组到能有效表达Ｋ９９菌毛抗原和ＬａｃＺ酶的ｐＧＫ９９之Ｋ９９基因ＢｇｌⅡ位点和ｐＵＣ１８的ＢａｍＨＩ位点中。通过ＳＴ１基因探针菌落原位杂交、特定酶切分析及ＤＮＡ序列分析，筛选并鉴定出了理想重组子，从而构建出了能分别表达ＳＴ１融合基因产物的工程菌株ｐＳＫ２１９和ｐＸＳＴ１。     

漆树酶在漆酚树脂上的固定化研究

介绍了漆酚树脂吸附金属离子后对漆树酶的固定化方法，比较了Ｆｅ＾３＋和Ａｌ＾３＋、漆酚树脂和漆酚－水杨酸接枝树脂对漆树酶的固定化结果显示，漆酚－水杨酸－Ａｌ螯合树脂对漆树酶的固定化活力最高，测定了溶液ＰＨ，环境温度对固定化漆树酶活性的航固定化漆酶的重作用性。另外，测定了固定化漆树酶的米氏常数，Ｋｍ＝４．９×１０＾－３，并讨论了Ｋｍ小于天然漆树酶的米氏常数的原因。     

Factors influencing decline in soil pH in Hawaiian Eucalyptus and Albizia plantations

Soil pH declined from 5.9 to 5.0 in 8 years beneath plantations of Eucalyptus saligna (Sm.) in Hawaii. In stands of Albizia falcataria, (L.) Fosberg, the soil pH change was more dramatic, declining from 5.9 to 4.6. We measured several components of soil acidity beneath four mixtures of the two tree species to gain insight on the processes responsible for the decline in soil pH. These components were studied using an empirical method of comparing acid quantity, degree of neutralization (depletion of base cations), and acid strength. The decline in soil pH differed between species as a result of differences in the degree of neutralization of the soil exchange complex; the larger decrease in soil pH under Albizia was produced by greater acidification of the exchange complex. Empirical titration curves suggested that differences in acid strength moderated the divergence in soil pH beneath the species. Had the acids accumulating in the soil under Albizia been as strong as those in the Eucalyptus soil, the difference in soil pH would have been greater. Though the two species had contrasting effects on soil pH, the differences in degree of neutralization, responsible for the pH decline, were small compared with differences in the amount of cations stored in tree biomass. Continued supply of nutrient cations (from weathering or fertilization) will ultimately control both the extent of soil pH decline and the level of productivity sustained by the forest.     

Monoclonal antibodies to bovine viral diarrhea virus: cross-reactivities to field isolates and hog cholera virus strains.

Monoclonal antibodies to bovine viral diarrhea virus (BVDV) were examined for binding with a large number of North American BVDV isolates and eight strains of the serologically related pestivirus, hog cholera virus (HCV). No single BVDV monoclonal antibody reacted with all BVDV isolates. The most cross-reactive monoclonal antibody was an anti-p80/p125 antibody which showed a positive reaction with 173 of 180 (96%) North American isolates. From a fewer number of isolates tested, one anti-gp53 monoclonal antibody also showed a high cross-reactivity (94%). All BVDV isolates showed a positive reaction with at least one of the seven monoclonal antibodies in the panel. Thus, the results indicated that a pool of these monoclonal antibodies may be used in place of polyclonal antisera for the detection of BVDV contamination of cell lines or for virus isolation. For HCV, all three anti-p80/p125 monoclonal antibodies reacted positively with all eight virus strains. In contrast, none of the anti-gp53 monoclonal antibodies were reactive to HCV strains. Thus, the anti-gp53 monoclonal antibodies may be useful for distinguishing between usually innocuous BVDV infections and the highly significant HCV infections in swine for foreign animal disease surveillance.     

Comparative effects of mu and kappa opiate agonists on the cecocolic motility in the pony.

The electrical and mechanical activity of the large intestine and its response to administration of opiate mu and kappa agonists were assessed from electrodes and inductograph coils chronically implanted on the cecocolic segment in six ponies given a diet of hay and concentrates. Before the drugs were given, migrating complexes propagating from the cecum into the colon occurred at the rate of 1.5 to 16/hour. During this propulsive activity, the cecocolic sphincter opened and closed allowing the outflow of cecal contents and preventing the backflow of colic contents. Each pony was used as its own control and was given fentanyl (0.01 and 0.05 mg/kg of body weight, IV) and U50488H (0.1 and 0.5 mg/kg, IV) at weekly intervals. The mu agonist fentanyl elicited a marked phase of inhibition of the propulsive activity and a closure of the cecocolic sphincter that lasted one to two hours depending on the dose. The kappa agonist U50488H induced an inhibition of the short spiking activity, i.e. of the resting muscle tone. It did not disturb the occurrence of migrating complexes nor that of the openings of the cecocolic sphincter. These kappa compounds may be drugs of choice to alleviate visceral pain in colic stases without inducing delay of transit unlike mu compounds.     

原木灵芝孢子粉和浸膏粉中的牛磺酸

采用热水提取－磺基水杨酸沉淀法进行样品的前处理，利用氨基酸自动分析仪测定供试样品的牛磺酸含量。试验结果表明，原木灵芝孢子粉和破壁孢子粉中牛磺酸含量分别为8．44mg/100g-9.23mg/100g和7．34mg/100g-7.89mg/100g，而灵芝浸膏粉中牛磺酸含量高达140．82mg/100g-157.38mg/100g.     

果树水分胁迫研究进展

从水分胁迫对果树叶、根的形态指标及显微结构 ,叶片气孔行为、光合作用、光抑制、活性氧代谢、脂氧合酶代谢、多胺代谢、脯氨酸、核酸代谢、内源激素变化等生理生化方面综述了近十几年来的研究成果 ,为全面研究果树抗旱机理及进一步制定抗旱措施奠定理论基础     

茉莉酸对苹果气孔运动及抗旱性的影响

50、75、100、150 mg／L JA处理苹果叶片表皮，使开放气孔的气孔开度分别减小27．4％、37．5％、56．9％和63．8％，使关闭后的气孔在光下开放时气孔开度分别减小15％、18％、28．8％、52．5％、61．3％；处理植株后干旱胁迫，叶片相对电导率分别降低15％、18％、31％、58％，脯氨酸含量分别提高0．09％、0．40％、0．42％、0．54 ng／gFW，可溶性糖含量分别提高1．89％、2．53％、3．80％、5．06％。25 mg／L JA处理与对照均无显著差别。JA的作用表现出明显的浓度效应。