中国香瓜与菜瓜地方品种资源白粉病抗性评价

春秋2个季节在温室利用风媒接种方法对搜集的102份香瓜和14份菜瓜种质资源进行了白粉病抗性评价,结果鉴定出7份香瓜和1份菜瓜高抗白粉病,其病情指数为零,1份菜瓜抗病,其病情指数0.9,表明我国香瓜和菜瓜地方品种资源中蕴涵着潜在的改良甜瓜白粉病抗性的基因资源。     

菌根与植被恢复

菌根不仅可促进植物的营养吸收、生长发育、抗病、抗逆,而且在保持良好的土壤结构、控制水土流失方面具有直接的作用。在我国西北许多地区,菌根菌与植物间的共生关系已被中断,要恢复该地区的植被,治本的方法应是重建植物与菌根菌的共生关系,形成健康的生态系统。文中还提出了菌根技术在植被恢复中的应用策略。     

Effect of cyclophosphamide on proliferation and apoptosis of rat mesangial cells in vitro

AIM:To investigate the effect of cyclophosphamide(CTX) on proliferation and apoptosis of mesangial cells(GMC) of rat in vitro. METHODS:GMC proliferat ion was detected by MTT method,GMC apoptosis was examined by inverted microscopy for phase-contract and fluoroscopy and flow cytometry analysis.The levels of Fas and Bcl-2 were also detected by immunohistology. RESULTS:The proliferation of GMC were inhibited by CTX, methylprednisolone(MP), low molecular weight heparin(LMWH). Apoptosis of GMC was induced by CTX, the apoptosis rate of GMC was 8.2%, and the Fas level was increased. CONCLUSION:CTX could inhibit proliferation and induce apoptosis of GMC possibly by enhancing the Fas level.     

发菜形态特征及其与环境因子的关系

通过野外调查和室内观察分析 ,天然发菜原植体的形态主要有柱状和带状两种 ;群体形态有单丝体、团块状、辫状、束状和网状。原植体的形态特征受环境湿度的影响较大 ,在降水量较大的地区 ,发菜原植体增粗 ,直径在 0 .0 5～ 0 .2 5 mm之间 ,带状发菜的比例较大 ,占 30～ 60 % ,吸水后藻体的颜色一般呈棕褐色 ;在降水量较小或极端干旱地区 ,发菜以细丝状为主 ,直径在 0 .0 2～ 0 .2 2 mm之间 ,带状发菜的比例不足 2 5 % ,吸水后藻体的颜色呈绿色或浅棕褐色。发菜群体形态的形成和发育与自身的生长特性有关外 ,主要与环境因子特别是降雨量、地形及自然外力 (地面径流和空气流动 )有关。     

Selection and amplification of the liver stem cell subset from rat bone marrow cells with a medium containing cholestatic serum in vitro

AIM: To explore the feasibility of direct separat and selective enlargement of the bone marrow-derived liver stem cells (BDLSC) from bone marrow cells with a culture system containing cholestatic serum in vitro. METHODS: Bone marrow cells of rats were cultured with selective media containing 2%, 5%, 7% and 10% cholestatic rat serum, respectively. The BDLSC were then induced to proliferate with the addition of hepatocyte growth factor (HGF) on the firth day. BDLSC were characterized using immunocytochemistry and RT-PCR for lineage markers, glycogen staining and urea synthetic assay for functions 2 weeks later. RESULTS: Bone marrow cells were unble to form colony in the presence of 2% cholestatic serum and apopotosis appeared gradually in 7% or 10% cholestatic serum. The BDLSC survived in the medium containing 5% cholestatic serum while the other types of cells did not. The survival cells proliferated with a high speed during the second week and then formed hepatocyte-like colony-forming units (H-CFU). Cells in the H-CFU expressed the characteristic proteins of fetal hepatocytes. Furthermore, they had glycogen storage and urea synthesis functions, two of the critical features of hepatocytes. CONCLUSION: The selective micro-environment effectively selected BDLSC from the bone marrow cell, and will be a new way to provide an abundant source of donor hepatocytes for clinical cell therapy.     

Effect of mutant β-catenin gene on the proliferation of hepatocytes

AIM:The β-catenin is a key molecule in the Wnt signal pathway, which plays a critical role in normal development and tumorigenesis. However, the mechanisms of the β-catenin on the cell growth control are still not completely defined. The aim of this study was to test the hypothesis that the mutant β-catenin may regulate the hepatocyte proliferation. METHODS: The immortalized murine hepatocyte cell line, AML12, was used for this study. A plasmid that contain mutant β-catenin S33Y was transfected into the AML12 cells and a stable cell line AML12S33Y was established. The cell growth property of this cell line and the parental cell were compared by flow cytometry analysis and direct cell count. The cells were also tested for the ability to form soft agar colonies, and the ability to form tumors in the severe immune deficient mice (SCID). RESULTS:1. The mutant β-catenin containing cell line AML12S33Y has higher proliferating index compared with the parental AML12 cells (P<0.01), suggesting that mutant β-catenin promotes cell growth. 2. The mutant β-catenin cells formed small colonies in soft agar after 4 weeks of culture, but did not generate tumor in SCID mice. CONCLUSION:The mutant β-catenin promotes liver cell growth.     

Effects of FK506 on anti-glomerular basement membrane nephritis in rats

AIM:To investigate the effects of FK506 on anti-glomerular basement membrane(GBM) nephritis in rats. METHODS: Anti-GBM nephritis model was elaborated by rabbit anti-rat GBM antibody injection in SD rats in this study. The rats were divided into three groups: FK506 treated group(0.5 mg·kg^-1·d^-1, sc), untreated nephritis control group and normal control group. FK506 was administered daily six hours after injection of anti-GBM IgG. All the rats were observed urinary protein at the 4th day, the 14th day and the 21st day. At the same time, the kidney specimens were collected, and T cell transforming function was also monitored.RESULTS:Rats injected with rabbit anti-GBM Ab developed heavy proteinuria by 4 days, and serum creatinine and serum urea appeared which kept on the rising. Glmerular hypercellularity, crescents, and protein casts were observed in nephritic rats. By electron microscopy, the thickening of GBM and loss of foot processes were seen. T cell transforming function was higher than normal. But, all pathological changes obviously turned for the better in FK506 treated group. CONCLUSION:FK506 could inhibit the progression of rat anti-GBM nephritis.     

Powdery Mildew of Prairie Gentian: Characteristics,Molecular Phylogeny and Pathogenicity

In March 1999, we found prairie gentian (Eustoma grandiflorum) infected with powdery mildew in a greenhouse in Oita Prefecture, Japan. Morphological observation revealed that the causal fungus belongs to the mitosporic genus Oidium subgenus Pseudoidium [teleomorph: Erysiphe sensu Braun and Takamatsu (2000)]. Precise taxonomic position of the fungus, however, is uncertain due to lack of the perfect stage. We determined the nucleotide sequence of the rDNA ITS region of the fungus. Comparison of the sequence with those obtained from DNA databases of this fungal group revealed that the sequence is identical to those of powdery mildews from garden four-o'clock (Mirabilis jalapa) and broad bean (Vicia faba). Inoculation of an isolate from garden four-o'clock caused mildew on prairie gentian and broad bean, suggesting that the prairie gentian mildew originates from garden four-o'clock or broad bean. Molecular phylogenetic analysis indicated a close relationship of this fungus to Erysiphe baeumleri on Vicia spp. and E. trifolii on Trifolium pratense. From these results, we propose that prairie gentian mildew diverged from a Fabaceae-parasitic ancestor. Received 14 March 2002/ Accepted in revised form 28 May 2002     

区域旅游资源开发定位研究——以内蒙古赤峰市为例

区域旅游资源开发是发展区域旅游的基础 ,开发的定位研究有助于为一地旅游业的发展指明方向。本文从区域角度和空间经济一体化思想出发 ,以赤峰市为例 ,通过对旅游资源的定量与定性研究 ,得到旅游资源的综合评价图式 ,结合区际分析归纳出赤峰市旅游资源开发利用的方向和层次。从而为区域旅游开发的定位研究进行了一般理论的探讨及例证分析     

几种除草剂药液表面张力、叶面接触角与药效的相关性研究

在除草剂氟磺胺草醚、灭草松和精喹禾灵药液中添加不同浓度的喷雾助剂ABS(十二烷基苯磺酸钠)和JFC ,以温室盆栽法测得各处理抑制杂草的效果,结果表明,在多数情况下添加喷雾助剂可使3种供试除草剂的药效显著提高。