铁皮石斛类原球茎增殖和分化的研究

通过单因素浓度试验和正交试验研究了5种金属离子、不同激素组合及不同天然附加物对铁皮石斛类原球茎增殖、分化的影响。试验结果表明,5种金属离子对类原球茎增殖影响的主次顺序为Mg2+(Fe2+(Ca2+(Mn2+(Zn2+,类原球茎增殖的最佳培养基为1/2MS+NAA 0.5mg/L+10%马铃薯汁+3%蔗糖(含Mg2+1.0 mmol/L、Ca2+2.0 mmol/L、Fe2+0.1mmol/L、Mn2+0.1mmol/L和Zn2+0.03 mmol/L)。培养基1/2MS+NAA 0.5mg/L+20%马铃薯汁+蔗糖20g/L+琼脂0.8g/L最适于铁皮石斛类原球茎的分化。     

Effect of diets containing low levels of methionine and oxidized oil on body composition, retina structure and pigmentation success of Japanese flounder

Diets reduced in methionine (Met) and with oxidized oil were formulated to induce visual deficiencies in Japanese flounder, Paralichthys alivaceus (T. & S.), in an attempt to link vision with pigmentation development. Even though Met-deficient diets have proved to be cataractogenic in salmonids, no cataracts were formed in flounder eye. However, both diets produced an abnormal morphology in the retinal pigment epithelium and the photoreceptor outer segments of the fish retina. The high presence of dead nuclei in the photoreceptor inner segment suggests a loss in the visual capability of fish fed these two diets, which produced lower pigmentation success than the control. A significant correlation was also found between pigmentation success and fatty acid composition (docosahexaenoic acid and arachidonic acid) of the head polar lipid fraction. The results suggest that a deficient intake of amino acids and fatty acids produces a change in retinal structure and composition, leading to reduced visual capability and suppression of the development of normal pigmentary pattern in flatfish.     

胚胎干细胞研究进展

胚胎干细胞最重要的生物学特征是具有发育全能性。要想获得具有发育全能性的胚胎干细胞，必需选择适当胚龄的胚胎和用正确的分化抑制物。本文从鼠类胚胎干细胞的获得、维持及胚胎干细胞的特征、生物学功能以及其他哺乳动物胚胎干细胞的研究等方面综述了胚胎干细胞的最新研究进展。     

Multinucleate parietal cells and cytoplasmic inclusion bodies in the gastric epithelium of callitrichids

Inclusion bodies (IBs) and multinucleate cells can be associated with viral infections; however, IBs and multinucleate cells have been described in normal tissue and with non-viral disease processes in multiple species. We examined fundic stomach from 50 callitrichids histologically for bi- and multinucleate parietal cells and cytoplasmic IBs in gastric epithelial cells. Callitrichids represented included 6 genera: Saguinus (4 spp.), Leontopithecus (1 sp.), Mico (3 spp.), Cebuella (1 sp.), Callithrix (1 sp.), Callimico (1 sp.), and 13 unspecified marmosets. Gastric epithelial IBs were present in 46 of 47 (98%) of the callitrichids from which the stomach was sufficiently well preserved to identify IBs. Cytoplasmic IBs were identified in gastric surface pit epithelial cells (43 of 44, 98%), mucous neck cells (43 of 44, 98%), parietal cells (43 of 44, 98%), and chief cells (43 of 44, 98%). The IBs were eosinophilic, ovoid, round, elongate, or variably indented, sometimes slightly refractile, and 1–6 × 1–13 µm. IBs were sometimes perinuclear and molded around the nucleus. Electron microscopy of the gastric epithelium of one marmoset indicated that IBs were composed of intermediate filaments. The IBs did not stain with immunohistochemical markers for cytokeratin AE1/AE3 or vimentin. Binucleate parietal cells were found in 49 of 50 (98%) callitrichids, and multinucleate parietal cells were observed in 40 of 49 (82%) callitrichids. Gastric epithelial cytoplasmic IBs and bi- and multinucleate parietal cells are likely a normal finding in callitrichids, and, to our knowledge, have not been reported previously.     

新时期农村产业结构优化调整的研究

农村产业结构优化调整已经成为我国农业经济增长和社会经济发展的必然要求。文章在对农村产业结构优化调整内涵进行理论剖析的基础上,指出了新时期我国农村产业结构现状及存在问题,分析了推进农村产业结构优化调整的必要性和紧迫性,最后,结合我国农村发展现状提出了相应的农村产业结构调整对策建议。     

蝴蝶兰无性决繁规模化生产中玻璃化原球茎状体产生的原因及其恢复

对蝴蝶兰（Phalaenopsis）组培生产中引起原球茎状体玻璃化的原因以及玻璃化原球茎状体再利用的效果进行了研究。结果表明：随着激素质量浓度增高和继代培养时间的延长，原球茎状体玻璃化程度加重。当激素NAA为5mg/L、BA为10mg／L，继代培养到第9代时，2种培养基中玻璃化率分别高达71％和65％。玻璃化原球茎状体的平均增殖率仅为2．2％，再生植物率为183株／瓶，明显低于正常的原球茎状体的5．3％和1297株／瓶。玻璃化原球茎状体在无激素培养基中经2～3代培养后，玻璃化原球茎状体的数量下降到0．84％，玻璃化现象可得到明显恢复，恢复后的原球茎状体的分化能力和植株生长状态与正常原球茎状体一致，无变异现象发生，可继续应用于组培生产。     

温度对鸡腿菇形成及酶活性的影响

鸡腿菇在２９℃培养，无子实体形成。基物中羧甲基纤维素酶（ＣＭＣ）和滤纸纤维素酶（ＦＰＡ）酶活性较低，淀粉酶活性较高，至２０天左右，酶活性达到高峰。在１９℃培养，随着子实体的形成，ＣＭＣ和ＦＰＡ酶活性迅速达到高峰。可见ＣＭＣ，ＦＰＡ酶活性的增加，淀粉酶活性的降低与培养温度和子实体的形成密切相关。     

培养基和添加物对蝴蝶兰原球茎分化幼苗的影响

以白色花系蝴蝶兰Phalaenopsis的原球茎(PLB)为材料,比较不同基本培养基(MS、NP、VW)、不同碳源(蔗糖、麦芽糖、山梨醇)和不同培养基添加物(椰子汁、马铃薯、香蕉)对蝴蝶兰PLB幼苗分化的影响.结果表明:以NP和VW为基本培养基时,PLB分化幼苗优于MS培养基;NP和VW相比较,NP培养基有利于幼苗地上部的生长,VW培养基则对PLB根的分化有良好影响;3种培养基添加物中,椰子汁和马铃薯优于香蕉;3种碳源相比较,蔗糖有利于苗的分化和生长.     

被污染水体的植物修复技术研究进展

本文从植物对水体富营养化的修复、重金属污染水体的修复、有机污染物的水体修复等方面,综述了近年来国内外关于植物修复技术对污染水体的研究及应用现状,并对植物修复技术的发展方向进行了展望。     

家蚕蛹体表预处理对高雄山虫草感染效果的影响

采用体表感染法以高雄山虫草茵丝段侵染家蚕蛹,对家蚕蛹体表进行预处理以提高感染率.试验研究了不同消毒剂、黏附分散剂和细菌发酵液预处理家蚕蛹体表后对感染的促进作用.结果表明:供试表面消毒剂提高感染率的能力为:5％聚维酮碘＞3％过氧化氢＞2％的汞溴红＞0.5％碘伏＞75％乙醇;0.05％吐温-80对高雄山虫草感染家蚕蛹有一定促进作用.不同浓度的高岭土与细菌发酵液无促进感染的作用.