陕甘宁老区脆弱生态环境定量评价——以榆林、延安两市为例

位于黄土高原中部的陕甘宁老区生态环境极为脆弱 ,近年来由于气候、人类开发资源等自然和人为原因 ,使生态环境的脆弱程度升高。选定年降水量、年均温、蒸发量等 8个指标 ,定量评价各县 1 970 - 2 0 0 0年的脆弱度状况 ,结果表明榆林、延安两市生态环境整体脆弱 ,脆弱度存在空间差异但差异不明显 ,时间段上的波动幅度不大。陕甘宁老区脆弱生态环境具有不稳定性 ,对外界干扰较敏感。     

不同粘度矿物油助剂对除草剂活性的影响

室内及温室内测定了10种不同粘度矿物油助剂对除草剂防除苘麻和稗草药效的影响及对玉米苗期的安全性。结果表明,10种矿物油助剂均不同程度地增加了氰草津和烟嘧磺隆防除两种杂草的活性。其中粘度为46 mm2/s (40℃)的矿物油乳剂(MOC46)对供试除草剂药效的增强作用最为明显,其次为粘度32 mm2/s (40℃)的矿物油乳剂。10种助剂对氰草津药效的增强作用大于对烟嘧磺隆。MOC46对除草剂活性的增加由高到低依次为:莠去津、氰草津＞莠去津+氰草津、莠去津+烟嘧磺隆、氰草津+烟嘧磺隆＞烟嘧磺隆;对玉米苗期安全性依次为:莠去津、烟嘧磺隆、莠去津+烟嘧磺隆＞莠去津+氰草津、氰草津+烟嘧磺隆＞氰草津。氰草津与MOC46混用对玉米苗期药害较重。     

几种除草剂对水稻纹枯病菌的影响

研究了丁草胺、环庚草醚、草甘膦、苄嘧磺隆、吡嘧磺隆和环丙嘧磺隆6种除草剂对水稻纹枯病菌菌丝生长和菌核形成的影响。结果表明,在一定浓度范围内,6种除草剂均能抑制菌丝生长,减少菌核形成数量,且浓度越高,抑制能力越强,但在较高浓度范围内,除草剂可增加菌核体积;吡嘧磺隆在5μg/ml、环丙嘧磺隆在10μg/ml时可增加菌核形成数量;在含除草剂培养基上产生的菌核都可萌发。     

25s rRNA 基因部分序列比较在香菇栽培菌种鉴定上的应用

对目前中国7个主要香菇栽培品种：科，26，939，135，9311，申10和7402和25s rRNA基因中的D1／D2片段进行了DNA序列测定，根据DNA序列测定结果对它们之间的同源性进行了分析。结果表明，所测定的7个香菇栽培品种之间的亲缘关系非常近，同源性很高。通过聚类分析，根据香菇之间的亲缘关系，可以将这7个品种分为2类，即苏香，939和9311为一类，26，申10，135和7402为一类。     

姬松茸与双孢蘑菇不同菌株的RAPD扩增研究

以4个姬松茸菌株和2个双孢蘑菇菌株为材料，用20个随机引物对它们进行RAPD扩增，通过对供试菌株遗传相似系数的估算和系统聚类分析，构建姬松茸和双孢蘑菇遗传相关树状聚类图谱，结果表明，进行RAPD扩增的20个随机引物中，有12个能产生三种带型，当遗传相似系数升至0.8713时，这6个菌株被分为3类，第一类为菌株18和26，第二类为菌株13和12，第三类为菌株33和45。     

强光下姜叶片的光呼吸及叶黄素循环

 姜叶片晴天中午的表观量子效率( AQY) 和PSÒ光化学活性(Fv/ Fm) 显著降低, 表明有明显的光抑制现象, 而干旱、高温、强光等逆境条件可显著加重光抑制程度。土壤水分胁迫使光呼吸速率( Pr) 降低, 峰值提前, Pr/ Pn 升高; 同时使叶黄素循环库增大, (A+ Z) / ( V+ A+ Z) 上升, 表明光呼吸和叶黄素循环是姜叶片耗散过剩光能的重要途径。     

早熟、优质、耐贮梨新品种新梨7号选育研究

以库尔勒香梨为母本,早酥梨为父本,有性杂交选育成新梨７号品种。该品种同时兼备优质、早熟与耐贮藏性;该品种遗传了父本的早熟性,比父本更早熟１５~２０ｄ,盛花期~果实可食期约８０~９５ｄ,属于早熟品种;且遗传了母本品质性状的质地酥脆、耐贮、清香、阳面红晕,比母本果个大,果心小。果柄木质化,丰产抗风。新梨７号果实贮藏期的可溶性固形物、果实重量、果实硬度和果实前期腐烂率的变化与库尔勒香梨基本相似,但耐热能力高于母本。凡适宜香梨、早酥、苹果梨和巴梨种植的地区,都适宜该品种的种植。     

Establishment of chronic obstructive pulmonary disease rat models by passive cigarette smoking and intratracheal instillation of lipopolysaccharide

AIM:To establish rat chronic obstructive pulmonary disease(COPD) models by passive cigarette smoking plus intratracheal instillation of lipopolysacchride(LPS) or passive cigarette smoking only, which would be similar to the pathogenesis of human COPD. METHODS:48 Wistar rats were randomly divided into 4 groups.(1) Healthy control I group(n=12), rats were bred 4 weeks;healthy control II group(n=12), rats were bred for 3months. (2) Model group I (n=12), 200μg lipopolysaccharide(LPS) was instilled intratracheally once for every two weeks and the rats were exposured to 5% of cigarette smoke, 0.5 h/d for 4 weeks.(3) Model group II(n=12),rats were exposed to 5% of cigarette smoke, 0.5 h/d for 3 months. The pathologic changes of airways and lung tissues, pulmonary function and blood gas analysis were determined. The airway wall lymphocytes and alveolar macrophages were counted. The cross areas of epithelial layer, smooth muscle layer and lamina propria of bronchi were measured. The hydroxyproline of lung tissue homogenates was determined by biochemistry method.RESULTS:The pathologic changes of airways and lung tissue of two models were similar to but milder than those of COPD patients(biopsy data). The collagen deposition and the cross areas of epithelial layer and smooth muscle layer in airway walls of two model groups were significantly increased than those of control groups(P＜0.01,P＜0.05).FEV_0.3/FVC% of two model groups, PaO₂ and SaO₂ of model I group were significantly decreased, while R_i and R_e in model I group were significantly increased than that of control I group(P＜0.05). The PaCO₂ and the counts of lymphocytes and alveolar macrophages of both model groups were significantly increased than those of the control groups (P＜0.01). Lots of alveolar macrophages had phagocyted smoke granules. The amounts of hydroxyproline of two model groups were significantly increased than those of control group((P＜0.05) and were negatively related to the FEV_0.3/FVC%, respectively (P＜0.01,P＜0.01) and positively related to airway resistance of model I group(P＜0.01). CONCLUSIONS:COPD rat models were successfully established by passive cigarette smoking plus intratracheal instillation of LPS and cigarette smoking only. The pathologic changes were similar but milder than those of COPD patients. The airway obstruction of model I group was more severe than that of model II group, but they have no significant difference.     

Relationship between expression of somatostatin and DNA ploidy in breast cancer

AIM: To investigate the relationship between somatostatin and the pathologic type, estrogen receptor,DNA ploidy of nuclei in tumor cells of breast cancer.METHODS: 67 cases of primary breast cancer and 25 cases of benign breast tumor were examined by immunohistochemical stretomyces avidin peroxidase method. 26 cases of breast cancer selected at random were analyzed by flow cytometry.RESULTS: Somatostatin expressed significantly higher in low malignant breast cancer than that in high malignant breast cancer (P<0.05). Most of cancers with positive staining of somatostatin were diploidy,most of cancers with negative staining were aneuploidy,there had significant difference between two groups (P<0.05).CONCLUSION: Somatostatin may delay the progress of breast cancer,and somatostatin levels in cancer tissues may become a useful indicator for assessing prognosis of patients with breast cancer.     

稻水象甲发生规律与药剂试验方法的探讨

稻水象甲是国际检疫对象，已经是我国北方水稻产区最重要害虫之一，并且呈迅速蔓延之势。此虫主要借助交通工具作远距离传播。成虫危害叶片，幼虫危害根系。一年繁殖一代但有两个危害高峰。新农药田间药效试验如果针对防治成虫、幼虫或者兼治，应在相应的时间、采取不同的方法进行。