香蕉分生小球体途径胚性细胞悬浮系的建立

 以7 个香蕉品种未成熟雄花为外植体均获得了分生小球体(meristematic globules) 。分生小球体的诱导率因基因组型和品种而异, 为15 %～81 % , 分生小球体的特点及开始出现的时间也受基因组型和品种的影响。以分生小球体为起始材料, 建立了‘广东2 号’、‘华农7 号’及‘河口龙牙’3 个品种的胚性细胞悬浮系, 并通过体胚发生途径获得了前两个品种的再生植株。     

茎瘤芥新品种涪杂1号的选育

涪杂1号茎瘤芥母本是胞质雄性不育系96118-3A,父本是优良的茎瘤芥自交系920154。该一代杂种从出苗至现蕾150～155 d(天),属中熟类型。瘤茎近圆球形,加工性能好,品质优,适于四川盆地茎瘤芥产区种植,一般每667 m2产量2 500—3 000 kg,最高可达4 000 kg。     

β-氨基丁酸、茉莉酸及其甲酯诱导辣椒抗TMV作用的研究

β -氨基丁酸 (BABA)、茉莉酸 (JA)及其甲酯 (MeJA)喷雾处理辣椒叶片和茎秆后可诱导辣椒获得对TMV的抗性。研究结果表明 :3种诱抗剂对不同辣椒品种所表现的诱抗效果没有显著差异 ;诱抗效果受诱抗剂的使用浓度、作物的生育期和TMV的接种浓度所影响 ;最高的诱抗效果可达到 5 0 %以上 ;BABA处理后 5～ 6d ,JA与MeJA处理后 6～ 10d接种TMV ,辣椒植株开始表达出较高的诱导抗性 ,这种抗性可持续 15d以上 ,并表现出与数量抗病性相似的特性。     

台湾稻螟发生期预测技术与应用

作者采用室内外结合的方法,根据台湾稻螟幼虫、蛹、卵的形态特征,制定了台湾稻螟分龄分级标准,并按所测定的相应虫态历期,采用分龄分级法进行了3年的发生期预测验证,平均准确率达96.7％,用于指导大田防治1.93万hm~2,平均防治效果达85.8％。     

温度对稻茎毛眼水蝇实验种群增长的影响

试验结果表明:在17～31℃恒温范围内,稻茎毛眼水蝇的发育速率随温度上升呈逻辑斯蒂曲线趋势。幼虫、蛹存活率、成虫产卵量、种群增长指数随温度的上升呈抛物线趋势。卵孵化率在20～31℃范围内无显著差异,均在92％以上。在17℃和35℃时,孵化率下降至86.67％和76.36％。在35℃时,幼虫不能存活,成虫不产卵。     

对虾的免疫机制及其疾病预防策略的研究

在对虾的细胞免疫中血细胞是主要的作用因素,而体液免疫是血淋巴中的一些酶和调节因子,机体还可以被诱导产生特殊的免疫保护反应.应用免疫增强剂、疫苗和基因工程技术为预防对虾病害提供了有效的途径.本文根据国内外的有关资料,就对虾的免疫机制和疾病预防策略进行了综述.     

种植方式与种植密度对大力士高粱的影响

本试验用裂区设计,研究了大力士高粱在16种不同种植密度、3种种植方式下,产草量、生产速度、茎叶比、茎粗的变化情况。结果表明,在撒播密度为18 kg/hm2、条播为22.5 kg/hm2、穴播为28.5 kg/hm2时达到最高产量;生长速度在第53-55 d时最高,达5.7 cm/d;茎叶比随着产量的增加逐渐减少;茎粗随着种植密度的增大而有减小的趋势。     

Rat mesenchymal stem cells differentiate into neuron-like cells induced by berberine in vitro

AIM: To investigate whether berberine can induce rat mesenchymal stem cells (MSCs) to differentiate into neuron -like cells in vitro. METHODS: MSCs were separated from young rat femurs marrow and expanded in culture medium. MSCs were induced to differentiate by berberine. The morphological changes of MSCs were evaluated by light microscope.Neuron-spcific enolase (NSE), neurofilament (NF), glial fibrillary acidic protein (GFAP) were detected by immunohistochemistry. RESULTS: Induced by berberine for 8 hours,MSCs exhibited neurotype . The expression of NSE and NF in the neuron-like cells was positive, but the glial astrocyte marker GFAP didn't express. CONCLUSION: Berberine may induce adult rat MSCs to differentiate into neuron-like cells in vitro.     

Expression of cyclooxygenase-2 in IL-1β-stimulated mesangial cells is medicated by NF-κB/IκB signal pathway

AIM: To investigate the role of NF-κB/IκB signal pathway in the regulation of cyclooxygenase-2 (COX-2) expression in human mesangial cells (HMC). METHODS: The PGE₂ concentration in supernatants of HMC was measured by radioimmunoassay. COX-2 mRNA and protein expression were determined by RT-PCR and Western blot. Electrophoretic mobility shift assay (EMSA) and Western blot were used to detect the activity of NF-κB and degradation of IκB. RESULTS: IL-1β significantly upregulated COX-2 expression and PGE₂ production in HMC. Significant up-regulation of NF-κB activation, nuclear translocation of p65 subunit, and degradation of IκB α and IκB β were observed in IL-1β-induced HMC. CONCLUSION: Expression of COX-2 in IL-1β-induced HMC is mediated by NF-κB/IκB signal pathway.     

Regulation of MMP-2 and TIMP-3 expression by uPA signal transduction system in human bone giant cell tumor

AIM: To study effects of urokinase-type plasminogen activator (uPA) signal transduction on expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-3 (TIMP-3) in giant cell tumor of bone (GCT). METHODS: Expression of uPAR, MMP-2 and TIMP-3 in GCT tissue was detected by immunohistochemistry. Phosphorylation level of mitogen-activated protein kinase (p44) in uPA/uPAR signal pathway in cultured GCT cells was detected by immunoprecipitation. The expression of MMP-2 and TIMP-3 in cultured cells after treatment with uPA-ATF or anti-uPAR antibody was also detected by Western blotting. RESULTS: 1) Urokinase-type plasminogen activator receptor (uPAR) was positive on the cell membrane and in cytoplasm of some mononuclear stromal cells (MSCs) and multinucleated giant cells (MGCs); 2) MMP-2 was positive in the cytoplasm and on the cell membrane of almost all of MSCs and some of MGCs. The polar distribution of MMP-2 in the cytoplasm of MGCs was especially obvious; 3) The expression of TIMP-3 of some MSCs and MGCs in GCT was much lower than MMP-2. The positive signal also showed a prominent polarity; 4) After treatment with uPA-ATF, the phosphorylation level of p44 in GCT cultured cells was much higher than the control. Addition of anti-uPAR antibody in the cells remarkably down-regulated the phosphorylation level of p44 as compared with the control group, suggesting that uPA-ATF participates cell signal transduction and this reaction can be inhibited by anti-uPAR antibody; 5) uPA-ATF cell signal pathway up-regulated expression of MMP-2 and TIMP-3, while anti-uPAR antibody down-regulated the expression of MMP-2 and TIMP-3. CONCLUSION: These results demonstrate for the first time that uPA-ATF directly regulates the expression of MMP-2 and TIMP-3 by signal transduction pathway, and the over-expression of MMP-2 and TIMP-3 may play an important role in local osteolysis of GCT.