野牡丹采穗圃建立和扦插繁殖技术研究

经过2年来对野牡丹采穗圃的建立和管理及穗条的不同药剂浓度、不同扦插时间、穗条所处不同部位、不同的修剪方式试验研究,结果表明:(1)苗圃中选择的优树建立的采穗圃当年每株母树采穗量达18条～54条,丛生性母株留低桩1 cm～2 cm采穗量最大,达到54条/株;(2)穗条用200 mg.L-1GGR6生根粉处理后的扦插效果最好,生根率达到88.5%,清水处理的穗条扦插效果最差,生根率为68.5%;10月中旬是扦插野牡丹的最佳时间,成活率可达90.5%;枝条上部的穗条扦插成活率最高,可达91.5%;穗条的不同修剪方式对扦插成活率影响不明显,平均成活率80.4%。     

杜仲组织培养的研究

以杜仲无菌苗的幼茎为外植体接种于MS培养基上,并附加相应的植物生长调节剂进行杜仲愈伤组织的诱导和增殖的研究;另外,对不同培养基、光照条件、pH值等理化因子对杜仲愈伤组织增殖的影响进行了研究。结果表明,MS培养基(0．8％琼脂 3％蔗糖)附加2．0 mg／L NAA 0．5 mg／L6-BA有利于杜仲愈伤组织的诱导。B5培养基(0．8％琼脂 3％蔗糖)附加1．0mg／LNAA 1．5mg／L6-BA,并控制pH值为6．5,12 h／d光照有利于愈伤组织的增殖。     

促消化功能性韧性饼干的研制

鸡内金、陈皮、山楂是具有促消化作用的天然物质。通过正交试验确定三者在韧性饼干中的添加量,研制具有促消化功能的韧性饼干。在基本配方的基础上,确定最佳添加量(以面粉为基准)为:鸡内金1.0%,陈皮2.0%,山楂12.0%,可生产出色泽均匀、形状整齐、薄厚一致、酥松香甜、具有促消化功能的韧性饼干。     

木薯花叶联体病毒复制形DNA提取和克隆及其双体的构建

 木薯花叶病毒(Cassava mosaic virus)具有两个约2.7kb的单链环状DNA,属于联体病毒(Geminivirus)组。我们用氯化铯平衡密度梯度离心的方法,从染病烟草组织中部分纯化其复制型双链环状DNA,用合适的限制性核酸内切酶切成线形,将两个组份分别克隆到pUC19质粒中,再用合适的限制性核酸内切酶切开重组质粒,分别构建成了两个组份的头尾相连的双体,测定克隆的病毒DNA的侵染性工作正在进行。     

Modulatory effects of calf thymus extract on the subset of T lymphocytes in Trichinella spiralis-infected mice

The immunotropic properties of calf thymus extract (TFX-Jelfa) is connected with the mimic action of the thymus to modulate the differentiation, maturation and function of prothymocytes and mature thymus dependent (T) cells. The studies were carried out on CFW male mice aged 3 months. The animals were infected per os with 200 larvae of Trichinella spiralis. TFX-Jelfa was administered i.p. at a dose of 10 mg/kg seven times at 24 hour intervals prior to infection. The percentage of CD4+ and CD8+ in suspension of splenocytes and mesenteric lymphonode cells by flow cytometry using monoclonal antibodies coupled with fluorescein isothiocyanate (FITC) or phycoerythrin (PE) were determined. At the same time, cryostat preparations, made from jejunum and muscle samples, were examined by the direct immunofluorescence method using FITC-labeled antibody to mouse CD4+ and CD8+. It has been found that infection with T. spiralis in mice decreases the percentage of CD8+ splenocytes, while the percentage of CD8+ mesenteric lymphonode cells does not change. However, in infected mice the percentage of CD4+ spleen cells and mesenteric lymphonode cells is increased. It has been also found that during the course of infection an increase in the number of CD8+ and CD4+ cells in the basal lamina propria of the intestines was observed. In infected mice, CD4+ lymphocytes were visible in the inflammatory infiltrates of the muscle tissue on the 14th day, whereas CD8+ lymphocytes were first observed a week later. Pretreatment with TFX does not change the inhibitory effect of infection on the percentage of CD8+ splenocytes, but potentiates the percentage of CD4+ spleen cells and mesenteric lymphonode cells increased by infection. Furthermore, administration of TFX prior to infection also potentiates the stimulatory effect of T. spiralis on the number of CD8+ and CD4+ in the basal lamina propria of the jejunum, and on the number of CD8+ cells in the inflammatory infiltrates of the muscle tissue.     

苹果锈果病(ASSD)类病毒的侵染性

 用机械接种的方法研究了苹果锈果病类病毒(ASSV)的侵染性.在嫁接时将接种原滴于砧木和接穗的切面上,用针刺切面,然后观察症状表现,所有接穗都取自同一株健康“国光”.用半提纯的ASSD—RNA—1和ASSD—RNA—2接种的,成活的3株中有2株发病;用提纯的ASSD—RNA—1和ASSD—RNA—2接种的,成活的3株中有1株发病;用病组织的澄清汁液接种的,成活的4株中有1株发病;用缓冲液模拟接种的健康对照成活的5株均未发病.发病苗木的症状为叶片卷曲,随后叶片从叶柄处断裂.从发病的,不发病的及健康对照的苗木茎部提取核酸,用双向及两次聚丙烯酰胺凝胶电泳分析,表现症状的4株均测出了ASSD—RNA—1,未发病的及用缓冲液模拟接种的健康对照均未检测出类病毒核酸带.结果表明ASSD—RNA—1可通过机械传播,为苹果锈果病的类病毒病原提供了又一次证据,也表明ASSD—RNA—1代表了能独立复制的苹果锈病类病毒.     

植物病毒卫星RNA生防制剂CMV-S52防治番茄病毒病

 1976年Kaper等发现,有些黄瓜花叶病毒(CMV)中除含有CMV基因组RNA1-4外,还含有1种可伴随CMV复制的RNA5,称CMV卫星RNA,它的存在能够改变CMV在各种寄主上的症状及其严重程度,还能干扰CMV-RNA1-4的复制,降低植株内病毒浓度。     

含与不含前导序列的乙肝病毒表面抗原在转基因番茄中表达的研究

将携带有乙型肝炎病毒（ａｄｗ亚型）表面抗原（ＨＢｓＡｇ）基因和ＨＢｓＡｇ及其前导序列（ＨＢｓＡｇ＋ｐｒｅＳ１＋ｐｒｅＳ２）基因的植物表达载体ｐＲＯＫＩＩ，分别导入农杆菌ＬＢＡ４４０４中，通过叶盘转化法得到转基因番茄及其后代。Ｓｏｕｔｈｅｒｎｂｌｏｔ杂交证明现任中外源基因已插入到植物染色体中。ＥＬＩＳＡ检测结果表明用ＨＢｓＡｇ基因转化的番茄叶片和果实中都能表达ＨＢｓＡｇ，而用含ｐｒｅＳ的ＨＢｓＡｇ基     

清远市珍稀濒危植物资源和保护对策

１９９８年６月～２０００年６月,对清远市野生珍稀濒危植物资源进行了调查,发现野和珍稀濒危植物４１种,其中蕨类植物３科３属４种,裸子植物５科７属７种,被子植物２２科２８属３０种;国家一级保护稀有植物３种,国家二级保护渐危植物１２种,稀有植物１５种,广布种２种,国家三级保护渐危植物５种,稀有植物３种,省级保护稀有植物１种;另外还发现栽培的国家一级保护植物４种,二级保护植物２种。它们具有种类组成丰富,地     

乙酸对杜仲愈伤组织胶含量的影响

对培养基中影响杜仲愈伤组织胶合成的前体物质乙酸浓度进行了研究。结果表明,以S4代杜仲愈伤组织为原料,随着培养基中乙酸浓度的增加,杜仲愈伤组织中胶含量不断提高,但过高浓度的乙酸会抑制愈伤组织的生长;最适乙酸添加浓度为1.0~1.5 mm o l/L,此时,不会影响愈伤组织的生长,且其平均增长率为1 977.97%,其平均含胶量达原植株的81.20%,从而提高了杜仲愈伤组织的含胶量。