Sustainable cement-based concrete materials are primarily used for construction,among which vermiculite as lightweight fine aggregate gains more future development prospect.First,a bacterial solution was sprayed over vermiculite and wrapped using calcium sulphoaluminate(CSA)cement to replace with fine aggregate in concrete.Secondly,based on a preliminary test on compressive strength results,10％of Ground Granulated Blast Furnace Slag(GGBS)and a healing solution propor-tion of 9∶1 was selected for preparing self-healing concrete.The fine aggregate was replaced in concrete using vermiculite in 0％,5％,10％and 15％and the findings suggest that bacterial vermiculite replacement should be at most 5％to achieve better results in strength and durable properties.The strength enhancement observed for compressive strength,strength regain,split tensile strength,flexural strength,and ultrasonic pulse velocity were 29.22％,45.5％,34.02％,28.03％and 41.4％respectively.Surface crack healing at 7,14 and 28 days of BIVC was 38.23％,58.82％and 79.41％,which is 3-4％lower than internal crack healing.Microstructural analysis by Scanning Electron Microscopy(SEM),X-Ray Diffractometer(XRD),and Energy Dispersive Spectroscopy(EDS)reveals the existence of calcite,and it was formed due to the bio-mineral action of bacteria with available nutrients in sustainable concrete.

以伊藤杂种'和谐'(Itoh hybrids'He Xie')的鳞芽为材料建立离体快繁技术体系,可克服传统方法繁育较慢的缺点,加速伊藤杂种优良品种的繁育推广.采用单因子试验设计,分别探究不同灭菌时间、不同植物生长调节剂浓度、不同根诱导时间以及不同生根苗等级对'和谐'组培苗启动、增殖、生根和驯化效果的影响.结果表明,用2％次氯酸钠溶液的最佳灭菌时间为12分钟,鳞芽污染率为9.09％;最佳初始培养基配方为MS+1.5 mg·L-1 6-BA+0.2 mg·L-1 GA3+0.5 mg·L-1 AgNO3;最佳增殖培养基配方为MS+450 mg·L-1 CaCl2+0.5 mg·L-1 6-BA+0.2 mg·L-1 IBA+0.2 mg·L-1 GA3+0.5 mg·L-1 AgNO3,增殖系数为3.3;无根苗在根诱导培养基1/2MS+1.0 mg·L-1腐胺+2.0 mg·L-1 IBA上,经4℃低温暗培养8天后常温光照培养30天,再转入根形成培养基1/2MS+1.0 g·L-1 AC,培养20天生根率达66.7％;苗移栽的基质为珍珠岩:蛭石:草炭土=1∶1∶1(v/v/v),移栽60天后,一级苗成活率最高为52.0％,二级苗和三级苗则大部分死亡,表明生根质量对移栽成活至关重要.

高碱环境和土壤养分的匮乏严重限制了我国热带珊瑚岛土壤环境下植物的生长适应能力,因此,珊瑚砂改良对促进珊瑚岛植被恢复,维持珊瑚岛生态环境可持续健康发展具有重要意义.该研究通过室内土柱模拟试验,对比了同一梯度下 4 种常用土壤改良材料(蛭石、珍珠岩、生物炭和钙基膨润土)对珊瑚砂理化性质、氮素淋溶以及总氮含量的影响.结果表明,与对照(CK)相比,施用生物炭使珊瑚砂pH显著降低1.4%,钙基膨润土、生物炭和蛭石能够显著提高珊瑚砂的阳离子交换量至CK的24.21、10.43和9.43倍.同时,施用生物炭、钙基膨润土和蛭石并不能降低以硝态氮形式为主的氮素淋失,但是能显著减少其他途径的氮素损失,从而达到促进珊瑚砂氮素固持的效果,3 种改良剂施用下的珊瑚砂总氮损失相较于CK分别降低了 40.92%、27.32%和 25.09%.因此,施用生物炭、钙基膨润土和蛭石均能有效提高珊瑚砂土壤质量,对改良珊瑚砂和热带珊瑚岛植被恢复具有重要意义,其中生物炭的改良效果最为显著,是改良珊瑚砂的理想材料.

荒漠地衣石果衣Endocarpon pusillum中未能检测出任何次级代谢产物,然而,其共生菌基因组中却含有14个PKS基因和2个NRPS基因.通过激活培养后从中分离出3个次级代谢产物,4,6,9-三羟基-7-甲基-1H,3H-萘并[1,8-cd]吡喃-1,3-二酮(lamellicolic anhydride)、石果衣菌素A(endocarpin A)及石果衣菌素B(endocarpin B),后二者为新结构化合物.从其共生藻柯氏复球藻Diplosphaera chodatii中分离出3个脱镁叶绿素类化合物,即脱镁叶绿素甲酯酸b(phaeophorbide b)、13-表-脱镁叶绿素甲酯酸a(13-epi-phaeophorbide a)及脱镁叶绿素甲酯酸a(phaeophorbide a).其中脱镁叶绿素甲酯酸b具有中等的清除DPPH活性.

以玉米品种"农大108"为实验材料,用蛭石栽培,首先筛选出合适浓度的Hoagland营养液和γ-氨基丁酸(GABA),然后比较含有等量氮素的GABA(1 mmol/L)、甘氨酸(Gly)、甲硫氨酸(Met)、脲素灌根处理对玉米生长发育的影响.结果表明:Gly、Met与空白对照差异不大,GABA与脲素都能显著提高玉米发育进程,都可以提高硝酸还原酶活性,加快可溶性糖的消耗,促进蛋白质的合成,但二者无显著作用差异.在元素吸收方面差异显著,GABA较脲素显著增加了多种元素的吸收.