草甘膦对土壤微生物的影响

以东北地区黑土为材料,探讨草甘膦对土壤呼吸、土壤可培养菌种群数量、大豆固氮根瘤菌和大豆根腐镰刀菌数量的影响。研究结果表明,随着草甘膦浓度的加大,土壤呼吸的抑制作用增强,土壤中草甘膦含量为1 mg&;#8226;kg-1、10 mg&;#8226;kg-1、100 mg&;#8226;kg-1时,危害系数分别为1.20、0.322、0.0760,远小于无危害标准系数20,确定草甘膦对土壤微生物低毒或无实际危害。不同浓度的草甘膦对土壤真菌、放线菌种群数量具有一定影响。土壤可培养菌种群数量随草甘膦浓度的升高抑制作用逐渐增强,随着草甘膦加入时间的延长,真菌、细菌、放线菌的种群数量有所恢复,其中放线菌与真菌同细菌相比对草甘膦敏感,土壤细菌对草甘膦具有较强的耐受或降解能力。草甘膦对大豆根瘤菌和大豆根腐镰刀菌有一定影响,对大豆根瘤菌的抑制作用与草甘膦浓度呈正比;低浓度草甘膦对镰刀菌产生激活作用,高浓度草甘膦对镰刀菌具有抑制作用;伴随草甘膦加入时间的延长,其对大豆根瘤菌和大豆根腐镰刀菌的抑制作用逐渐减弱。     

遮光处理对金森女贞生长和光合特性的影响

研究不同遮光处理(0、20%、40%、60%)对金森女贞生长及光合特性的影响。结果表明:金森女贞具有较高的光饱和点(1 050μmol.m-2.s-1)和较低的光补偿点(53.88μmol.m-2.s-1),属于阳性植物,但具有一定的耐荫性;净光合速率日变化呈双峰曲线,有光合"午休"现象;不同遮光处理下,净光合速率平均值均高于对照,枝叶生长加快,比叶质量下降,叶绿素总量增加,a/b下降,其中以40%遮光处理效果最佳。     

渗透胁迫对连香树幼树生理特性的影响

以2年生连香树实生苗为试材,研究不同渗透胁迫对其生理特性的影响.结果表明,随着胁迫浓度的增加和时间的延长,叶片中总叶绿素含量明显降低.随着聚乙二醇(PEG)浓度的增加,可溶性蛋白、可溶性糖、脯氨酸和丙二醛(MDA)含量增加,保护性酶过氧化物酶(POD)活性升高,过氧化氢酶(CAT)活性下降,而超氧化物歧化酶(SOD)活...     

AM fungi and rhizobium regulate nodule growth,phosphorous (P) uptake,and soluble sugar concentration of soybeans experiencing P deficiency

To understand the mechanisms behind the beneficial combinations of the existence and formation processes of tripartite symbiosis of arbuscular mycorrhizal fungi (AMF) and nitrogen (N)-fixing rhizobia in phosphorus (P) deficiency. The effects of different inoculations of Bradyrhizobium japonicum (BJ) and Glomus mosseae (GM) on plant growth, P uptake, and soluble sugar concentration of soybeans in a P-deficient environment were investigated utilizing split-root systems supplemented with either KH₂PO₄ (0.01 mM, I-P) or Phytin (200 mg P kg^?1, O-P) for 56 days. Six treatments were applied: (1) mono-inoculation of BJ in organic P compartment, O-BJ; (2) mono-inoculation of BJ in inorganic P compartment, I-BJ; (3) mono-inoculation of BJ in organic P compartment and mono-inoculation of GM in inorganic P compartment, O-BJ/I-GM; (4) mono-inoculation of BJ in inorganic P compartment and mono-inoculation of GM in organic P compartment, O-GM/I-BJ; (5) dual inoculation of BJ and GM in organic P compartment, O-BJ/GM; and (6) dual inoculation of BJ and GM in inorganic P compartment, I-BJ/GM. Compared with sole inoculation of BJ, dual inoculation increased the plant and nodule biomass, which were higher in I-BJ/GM and O-BJ/I-GM treatments compared to O-GM/I-BJ and O-BJ/GM treatments. Roots inoculated with GM in I-P grew better regardless of whether BJ was inoculated or not. GM inoculation in I-P also increased the number of leaves and the rate of photosynthesis. Nodule P concentration following dual inoculation in I-P was increased 2.1-fold compared to that in sole inoculation with BJ. Shoot soluble sugar concentration with dual inoculation in O-P was less than that in the other three treatments. Inoculated with GM in I-P increased the root soluble sugar concentration compared with the non-GM plants or GM inoculation in O-P. The present findings may explain a regulatory system for the nutrition of beneficial microbial interactions by the nodule or by AM fungal hyphae at selecting the best performing tripartite symbiotic partners in P deficiency.     

羊角拗甙对日本血吸虫虫卵肉芽肿的影响

对人工感染18条日本血吸虫尾蚴的雌性小鼠分别于感染后41 d起灌服羊角拗甙及吡喹酮,观察其对小鼠肝内虫卵肉芽肿和肉芽肿内嗜酸性粒细胞的影响。结果表明,小鼠肝内虫卵肉芽肿平均直径和肉芽肿内嗜酸性粒细胞明显减少,羊角拗甙与吡喹酮对血吸虫虫卵肉芽肿具有明显抑制作用。     

日本血吸虫还原性辅酶I(SjNADH)基因的克隆表达及其免疫保护效果分析

为了评估日本血吸虫还原性辅酶I(SjNADH)在小鼠体内诱导的免疫保护效果,应用PCR获得SjNADH基因片段,其开放阅读框为474 bp,编码157个氨基酸,并在大肠杆菌中成功表达,纯化得到该重组蛋白。Western blot结果显示,SjNADH在日本血吸虫童虫和成虫中的表达量稳定,SjNADH融合蛋白也能被免疫血清识别,具有较好的免疫原性。应用重组蛋白免疫小鼠能诱导产生较高的特异性抗体水平,并诱导了20.13%的减虫率和23.06%的肝脏减卵率。结果表明,获得的SjNADH重组蛋白在小鼠体内诱导产生了部分免疫保护,有作为血吸虫疫苗候选抗原分子的潜力。     

日本血吸虫WD40信号蛋白的原核表达

本研究克隆了编码日本血吸虫WD40信号蛋白的cDNA,并分析了WD40在日本血吸虫不同发育时期的转录情况.同时还利用原核表达系统对该蛋白的部分序列进行了表达,并进行了重组蛋白的纯化和多克隆抗体的制备,Western blot分析表明本研究中获得多克隆抗体可与重组表达的蛋白和血吸虫全虫蛋白裂解物具有特异性反应.本试验结果为进一步研究WD40信号分子的功能奠定了初步基础.     

濒危物种连香树资源繁育与开发利用

介绍了连香树种资源分布的自然地理概况,人工繁育技术,人工幼林生物学特性及生长状况,并提出了有关连香树的开发利用和保护措施。     

基于2种中间寄主的稻螟赤眼蜂生命表编制与分析

旨在寻求适合繁殖稻螟赤眼蜂(Trichogramma japonicum Ashmead)种群的中间寄主。笔者以小菜蛾[Plutella xylostella (L.)]卵和甜菜夜蛾(Spodoptera exigua Hübner)卵为中间寄主,编制稻螟赤眼蜂的种群生命表,分析比较生殖参数,评价其对2 种中间寄主的适合性。结果表明,稻螟赤眼蜂在小菜蛾卵上的净生殖力R0、内禀增长率rm、周限增长率λ与平均世代历期T 分别为6.12、0.1996、1.2210、9.0728,在甜菜夜蛾卵上的上述各项参数分别为10.58、0.2573、1.2934、9.1678。稻螟赤眼蜂在甜菜夜蛾卵上各项生殖参数都要高于在小菜蛾卵上的表现。甜菜夜蛾卵较小菜蛾卵更适合用作稻螟赤眼蜂繁殖的中间寄主。     

Microbial inoculation of Rhizobium and phosphate-solubilizing bacteria along with inorganic fertilizers for sustainable yield of soybean [Glycine max (L.) Merrill]

A field experiment was conducted to assess the effect of microbial inoculants and inorganic fertilizers for sustaining the yield of soybean. Application of 100% recommended dose of fertilizer (RDF) gave significantly highest yield (2433 kg ha^?1) over 75% RDF (2317 kg ha^?1) and without RDF (2205 kg ha^?1). Seeds inoculated with Rhizobium (Bradyrhizobium japonicum) and phosphate-solubilizing bacteria (2480 kg ha^?1) gave significantly highest soybean yield over without inoculation (2191 kg ha^?1). Rhizobium and phosphate-solubilizing bacteria with 100% RDF (2674 kg ha^?1) gave significantly highest seed yield than rest of the treatment combinations. Root nodules and their dry weight were remained un-influenced due to fertilizer levels, whereas in bio-fertilizers, it was significantly higher with Rhizobium inoculation (24.3 and 408 mg, respectively) followed by dual inoculation of Rhizobium and PSB. 100% RDF and dual inoculation with Rhizobium and PSB earned Rs. 47916/- and Rs. 51182/- net returns per ha, respectively.