日本亮耳菌——一种新的杀线虫真菌

从贵州省宽阔水自然保护区采到的日本亮耳菌Lampteromycesjaponicus(Kawam.)Sing.这一中国新记录种,其菌丝体及其丙酮粗提物对线虫有毒杀作用,是一类有应用前景的食线虫真菌资源。     

云南新植物

发表天南星属(天南星科)一新种苍山南星Arisaema cangshanense X.D.Dong,通泉草一新变种,白花通泉草Mazus japonica(Thunb.)O, Kuntze var.leucanthus X.D.Dong和光叶蔷薇一新变种,重瓣光叶蔷薇Rosa wichuraiana Crep.var.multipetala X.D.Dong     

Genome Analysis of Lotus japonicus

Lotus japonicus , a model legume plant, was reviewed and compared with Medicago truncatula and soybean. Several mutant libraries are being analyzed, focusing on the nodulation mechanism. The first plant nodulation gene nin was cloned by Ac-transposon tagging. Soybean remains as the most studied legume, especially in relation to the disease resistance genes. However, Lotus japonicus offers several advantages for molecular genetics, and the remained lackings were recently filled up, namely 1) an appropriate crossing partner for Gifu, accession Miyakojima, was proposed for its 4% polymorphism and smooth recombining ability; 2) a genome library with long inserts, average of 140 kb, and 8.2 genome equivalents of library size, has been established; and 3) the rather low polymorphic rate between Gifu and Miyakojima can be overcome with the HEGS (High Efficiency Genome Scanning). With this infrastructure, positional cloning of the causative genes of several mutant libraries will be accomplished in a short term. Genome sizes of L. japonicus acc. Gifu and Miyakojima were determined with high accuracy, to be 494±0 MB and 512±1 MB, respectively. The feasibility of constructing a physical map of the entire genome, for functional genomics, was discussed. Received 5 September 2000/ Accepted in revised form 11 October 2000     

Large Scale Structural Analysis of cDNAs in the Model Legume, Lotus japonicus

Lotus japonicus possesses certain characteristics suited to molecular genetic and genomic analyses and has been adopted as a model species in the study of legume plants. To make a catalogue of genes expressed in L. japonicus and understand biological processes specific to legume plants, large scale EST analyses have been performed. To date, more than 26,000 EST sequences of L. japonicus have been deposited in the public databases. These sequences were developed by five laboratories using different organs. In this review, information obtained from two EST projects carried out in Japan is presented. Some 7137 non-redundant EST groups from young plants and 718 groups from flower buds were generated. A similarity search revealed that homologues of nodulin genes in other legume plants, as well as genes related to secondary metabolism, seed development and the reproductive process, were included in the EST collection, indicating the usefulness of the EST clones in the study of biological phenomena distinctive to legume plant species. Received 23 August 2000/ Accepted in revised form 22 September 2000     

学习经历在平腹小蜂寄主选择过程中的作用

研究了已经交配与未经交配的平腹小蜂在羽化后不同时间对中间寄主柞蚕卵信息记忆的持效性,比较了经学习训练与未经学习训练的平腹小蜂在不同时间对其自然寄主荔枝蝽卵和中间寄主柞蚕卵的选择性。结果表明：交配过的平腹小蜂在大量羽化后96h检验柞蚕卵的时间和数量都显著增多,而未经交配的平腹小蜂在此时搜索寄主的时间也显著延长,说明平腹小蜂在此时对柞蚕卵信息的记忆开始明显减弱。经学习训练的和未经学习训练的平腹小蜂在大量羽化后96h对荔枝蝽卵的第一选择数和刺卵数都明显提高,并且前者较后者在各个时段对荔枝蝽卵的第一选择数、检验卵数以及刺卵数都多,说明经学习训练的平腹小蜂对荔枝蝽卵的趋性较高,并且随着时间的延长受柞蚕卵信息的干扰逐渐减小,对荔枝蝽卵的学习效果不断增强。     

中国对虾继饥饿后的补偿生长研

1999年7至8月份,在25.0±0.5℃条件下对中国对虾（湿重,1.454±0.150g）进行了不同时间的饥饿处理后再供食的恢复生长实验。对照组C连续饱食投喂32d;处理组S4、S8和S12分别饥饿4、8和12d后再饱食投喂28、24和20d。主要结果如下饥饿结束时各处理组的干重和湿重显著低于对照组（P<0.05）;实验结束时S4组和对照组间的干重和湿重差异不显著（P>0.05）,而S8和S12两组的干重和湿重仍显著低于对照组（P<0.05）;恢复生长后各处理组的湿重摄食率显著高于对照组（P<0.05）。实验结果表明,中国对虾继饥饿后再恢复喂食出现完全或部分补偿生长效应,且这种补偿生长效应主要是通过恢复生长阶段食欲增大,摄食水平提高实现的。     

中国沿海日本囊对虾线粒体16S rRNA基因序列变异及遗传分化

对中国东南沿海4个日本囊对虾地理群体16S rRNA基因片段进行了序列测定和分析.在获得的467bp 序列中,共检测到45个变异位点,多态位点比例为9.64%.具有10种单倍型,三亚群体单倍型多样性最高(0.900±0.161).各群体的核苷酸多样性(π)为0.0007～0.0082,其中三亚群体核苷酸多样性最为丰富,远高于湛江、北海和海口群体.群体间遗传分化指数(F_(st))为0.000～0.945.结合已报道的16S rRNA基因序列,构建了NJ分子系统树,中国海域日本囊对虾可分为3支.香港至台湾沿岸所有单倍型聚集为一分支,湛江、海口和北海群体内的所有单倍型聚集成另一分支,两分支分别属于已报道的变种Ⅰ和变种Ⅱ,但三亚群体内的4个单倍型单独聚集成一分支,与前两分支的核苷酸序列差异大(7.95%～8.35%),遗传分化明显,可能为一亲缘关系很远的新种(或变种).研究结果可为日本囊对虾的资源管理和遗传选育提供参考.     

专一识别脱落酸甲酯的单克隆抗体的制备与应用

专一识别２－顺（Ｓ）ＡＢＡ甲酯的单克隆抗体来源于以ＡＢＡ分子中的１－ＣＯＯＨ为偶联位点合成的免疫原。它与游离态ＡＢＡ和结合态ＡＢＡ葡萄糖酯的交叉反应仅分别为１％与３．５％,而与ＡＢＡ类似物,如２－顺－黄质醛、紫黄质以及ＡＢＡ的２－反式异构体和（Ｒ）－对映体则无交叉反应。利用该抗体建立的高度灵敏和精确的ＡＢＡｍｅ酶联免疫测定法,其检测线性范围为０．０４８～１．５２ｐｍｏｌ。通过ＡＢＡｍｅＥＬＩＳＡ和ＧＡ１＋３ＥＬＩＳＡ分析可知羊蹄叶片衰老与内源ＧＡ１＋３／ＡＢＡ比值的下降有关。     

PCR方法制备地高辛标记DNA探针检测中国对虾非包涵体型杆状病毒

A pair of primers created from information of PmNOBⅢ genome DNA Sal I fragment produced a 355bp band by using Penaeus chinensis non occluded baculovirus (PcNOBV),the WSBV isolate from P.hinensis in mainland China,as the DNA template.The specific PCR product was cloned,sequenced and labeled with digoxigenin (DIG)DNA labeling kit(Boehringer Mannheim).The DIG labeled fragment was tested by dot blot hybridization for sensitivity and specificity with purified PcNOBV nucleocapsid,PcNOBV infected shrimp tissues and healthy shrimp tissues.The detection limit of the DNA probe is 6.8pg of purified PcNOBV DNA.No hybridization signals were observed using DNA from healthy shrimp as template.Healthy P.chinensis,artificially infected P.chinensis and pond reared adult P.chinensis were screened for PcNOBV infection by both PCR and the hybridization assay.The results showed a good relationship between PCR and the hybridization assay.These findings demonstrate that the DIG labeled probe can be used as a sensitive,specific and cost effective reagent for detection of PcNOBV.     

湛江棕囊藻对南美白对虾虾苗和多种鱼苗的毒性研究

测定了湛江棕囊藻赤潮海水和棕囊藻(Phaeocystis globosa)对南美白对虾(Penaeus vannamei Boone)虾苗、青石斑鱼(Epinephelus awoara)、鲻鱼(Mugil cephalus)和尖吻鲈鱼(Latescal carifer)鱼苗的毒性。结果表明,棕囊藻对虾苗有一定的毒性,24 h LC50为1.0×109 cells L-1,去除囊泡液后的棕囊藻碎片对虾苗毒性较弱,细胞密度为1.0×109 cells L-1时,24 h虾苗的死亡率仅为10%,赤潮海水对虾苗无毒性;棕囊藻囊泡液对青石斑鱼有一定毒性,24 h LC50为囊泡液占海水总体积的10.9%,赤潮海水对青石斑鱼苗无毒性;棕囊藻对尖吻鲈鱼和鲻鱼鱼苗无毒性。