不同时期喷施多效唑对花生生理特性、产量和品质的影响

为确定高产条件下不同花生品种的最佳化控时期,以小花生品种‘花育20’(HY20)和大花生品种‘花育25’(HY25)为试验材料,研究了多效唑(PBZ)不同喷施时期对花生根系活力、叶绿素含量、叶片保护酶和碳、氮代谢酶活性,以及荚果产量和籽仁品质的影响.结果表明:不同时期喷施PBZ均提高了2个品种花生在结荚期的叶绿素含量、根系活力,以及叶片超氧化物歧化酶、过氧化物酶、过氧化氢酶、蔗糖合成酶、蔗糖磷酸合成酶和磷酸烯醇式丙酮酸羧化酶活性,降低了丙二醛(MDA)含量以及硝酸还原酶、谷氨酰胺合成酶、谷氨酸脱氢酶和谷氨酸合成酶活性,且PBZ喷施时间越早效果越明显.在饱果期,HY25的各指标以主茎高25cm时喷施PBZ的效果最好,但HY20在主茎高25 cm时喷施PBZ的保护酶活性降低,化控时间过早导致植株早衰,叶绿素含量、根系活力以及碳代谢酶活性也略低于CK,HY20的指标以主茎高30 cm时喷施PBZ效果最好.适宜时期PBZ处理提高了2个品种的荚果产量和经济系数,提高了脂肪含量和油酸相对含量以及O/L值.高产条件下,HY25和HY20的最适多效唑处理时期分别为花生主茎高25和30 cm左右.     

福建省兰科植物2种新记录

在福建省武夷山药用植物资源普查中,发现2种兰科植物,经鉴定为七角叶芋兰Nervilia mackinnonii (Duthie) Schltr.和柄叶羊耳蒜Liparis petiolata (D. Don) P. F. Hunt et Summerh.,皆为福建省新记录。凭证标本存放于福建中医药大学标本室(FJTCM)。     

Some biological and genomic properties of rice tungro bacilliform badnavirus and rice tungro spherical waikavirus from Nepal

A survey of rice fields during the main growing seasons in 81 locations from 21 districts of the Southern Terai region of Nepal indicated that rice tungro was primarily restricted to the Hardinath (Janakpur) and Parwanipur (Bara) regions. The tungro incidence in Hardinath ranged from 17% to 51% and in Parwanipur from 6% to 61% causing about 89% grain yield loss in Hardinath. Both rice tungro bacilliform badnavirus (RTBV) and rice tungro spherical picornavirus (RTSV) were found in tungro isolates collected from Hardinath and Parwanipur. These isolates were transmitted by Nephotettix virescens and leaf extracts reacted to antisera against RTBV and RTSV. In a dot blot hybridisation assay, leaf extracts of 12 weed species collected from the tungro-affected area in Hardinath and Parwanipur also reacted with RTBV DNA probes. On mass inoculation of 15 popular rice cultivars most became more than 50% infected and only cv. Radha 9 had low (22.2%) infection. RTBV DNA and the coat protein region of RTSV from the Hardinath isolate were cloned and partially characterised. A comparative analyses by restriction endonuclease digestion, cross hybridisation, the polymerase chain reaction and partial sequencing indicated that the Nepalese RTBV DNA clone and the cDNA clones of the RTSV RNA were more similar to the various tungro isolates from the Indian subcontinent than to those from the Philippines.     

羟泰米酚的抗着床作用及其对小鼠子宫雌二醇和孕酮受体含量的影响

经雌激素拮抗剂－羟泰米酚处理后的怀孕小鼠,胚泡着床受到明显抑制;同时,着床前子宫细 胞质雌二醇受体和孕酮受体明显减少,细胞核受体明显增加;拮抗剂还使血清雌激素和孕酮含量显 著降低。结果表明：羟泰米酚的抗着床作用效应与子宫雌二醇受体和孕酮受体的正常功能受到干扰 可能是有密切关系的。     

青海花蝇科一新种（双翅目）

本文记述采自青海省花蝇科泉种蝇属一新种。单锥泉种蝇Ｐｅｇｏｈｙｌｅｍｙｉａ ｍｏｎｏｃｏｎｉｃａ ｓｐ．ｎｏｖ．模式标本保存在中国科学院上海昆虫研究所。     

多天线糖链对运铁蛋白与受体结合及内吞的研究

应用系列凝集素柱层析法（伴刀豆球蛋白,小扁豆凝集素,欧曼陀罗凝集素）分别从正常人血清及孕妇血清中提纯含有二天线无核心岩藻糖复杂型糖链的运铁蛋白及含有多天线无核心岩藻糖复杂型糖链的运铁蛋白。与正常的含有二天线糖链的运铁蛋白相比,含有多天线糖链的运铁蛋白与ＳＭＭＣ－７７２１细胞膜表面的运铁蛋白受体的亲和力下降,但最大结合量不变,此外,其在内吞过程中于细胞膜上的停留时间延长。结果表明糖链结构改变对运铁蛋白的功能有影响。     

鸡肝二氢叶酸还原酶在盐酸胍溶液中构象的序变与激活

用蛋白质内源荧光、疏水荧光探针TNS及蛋白酶K限制性酶解等方法研究了二氢叶酸还原酶在盐酸胍变性过程中的构象变化及动力学,并与活力变化进行了比较.TNS可以监测到与激活同步的构象变化;盐酸胍浓度大于0.75mol/L时,二氢叶酸还原酶被蛋白酶K水解速度增大;当盐酸胍浓度大于1.2mol/L时,才能监测到酶分子整体构象的变化.以上结果表明二氢叶酸还原酶在盐酸胍溶液中的变性并不符合标准的二态模型,而是先经历构象逐步松散的序变过程,然后发生协同的构象伸展.二氢叶酸还原酶在低浓度盐酸胍溶液中的激活是由于酶活性部位构象的微小变化引起的.酶活性部位构象的变化虽然降低了酶与废物的结合能力,但加快了酶促反应限速步骤,即底物解离速度而使酶活力升高.     

Functional expression of opioid receptor—like receptor and its endogenous specific agonist nociceptin／orphanin FQ during mouse embryogenesis

INTRODUCTIONOpioidreceptorsbelongtotheG-protein-coupledreceptorfamilythatischaracterizedbytheseventransmembranespanningdomainsinstructure.Threesubtypesoftheopioidreceptors(H,6,andK)havebeenclonedandcharacterizedthroughtheir1.CorrespondingauthorFunctionalexpressionofORLIandN/OFQduringmouseembryogenesisdistinctaffinitiesfordifferentopioidligands.TheseopioidreceptorsareallcoupledtotheinhibitoryGprotein(Gi)andnegativelyregulateadenylatecyclase[1].Opioidreceptor--likereceptor(ORLI),anew…