Distribution,length and weight of roots in young plantations ofEucalyptus grandis W. Hill ex Maiden irrigated with recycled water

Summary The root systems ofEucalyptus grandis W. Hill ex Maiden, irrigated with recycled municipal effluent at two sites in north-western Victoria, Australia, were studied by excavation and coring. Trees at Robinvale were four years-old and were irrigated using micro-sprays that covered only 70% of the ground surface area, whereas at Mildura, effuent was uniformly was uniformly applied to six years-old trees by flood and sprinkler irrigation. At Mildura where roots were excavated from a 2.80×2.80×1.20 m block of soil, a total root length of 1193 m.m⁻² and a total root weight of 3.1 kg m⁻² were estimated in the top metre. For roots >1 mm diameter, 77% of intercepts were at 0–30 cm, whereas only 50% were in the 50–100 cm soil horizon. At both sites where roots in the top 30 cm were studied by coring, the vertical distributions of root intercepts, length and weight were similar. Root length was greatest in the 0–10 cm soil horizon at both sites, and intercepts of roots <1 mm diameter comprised 73% and 81% of all roots at Mildura and Robinvale respectively. Roots <1 mm diameter contributed 85% of total length at both sites, but only 19% and 21% of total weight at Mildura and Robinvale respectively. The horizontal distribution of roots differed at the two sites. With uniform application of effuent at Mildura, root intercepts and length were concentrated in the centre of the irrigation bay, but at Robinvale, the concentration occurred closer to the tree row due mainly to the different method of irrigation. Root weight at both sites was highest within 50 cm of the tree row. Root densities of 0.11 to 0.57 cm cm⁻³ were estimated in the two plantations; these were similar to root densities measured inPinus radiata D. Don plantations up to 46 months old, but were considerably lower than those estimated for pastures. The implications of the results for the management of irrigated plantations of eucalypts are discussed.     

中国东方铃蟾(Bombina orientalis)皮肤中C_(-12-b)肽的分离与鉴定

东方铃蟾鲜皮的甲醇提取液,可引起大鼠离体平滑肌的收缩。此液经碱性氧化铝柱层析分离,其80%乙醇洗脱的 C 组分显示生物活性。C 组分再经葡聚糖凝胶 G-15柱分离,其活性较强的早期洗脱组分 C_(_12),可被糜蛋白酶水解灭活,但其活性并不被5-HT 拮抗剂赛庚啶[2×10~(-6)mol/L]完全拮抗。继用反相高效液相色谱(RP-HPLC)分析,见分离出的 C_(_12_h)峰与铃蟾肽~*(Bombesin,BBS)的出峰时间相同,且具相同的氨基酸组成。上述实验结果提示,C_(_12_h)肽可能就是铃蟾肽。     

初期采脂对马尾松木材构造的影响

广东省韶关林场采用标准的采脂工艺,在其马尾松人工林进行了两年的初期采脂试验。 在这些马尾松的采脂树的采脂盘上,主要呈现泌脂和木材增生,而在其下方距离0.5m的影响盘上。仅有一些创伤轴向树脂道和树脂囊。创伤树脂道使其邻近的轴向管胞的形状不规则,又与树轴倾斜近45°。 从山中试验区不同的松树林分,在其对照盘(对照树的)、影响盘上,自髓向外每隔一个生长轮的离析材料;另在采脂盘上密切邻近采脂面两侧,自圆盘周围向内各选4轮材料;分别测定轴向管胞的长度,得知这些30(20)年生的马尾松树仍在幼态期间,其管胞长度一般是增加的;至于采脂面两侧的管胞却显出不同程度的减短,其中一些管胞呈现种种不规则形状。     

湿地松与茶树间作根系分布状况的研究

湿地松(Pinus elliottii)是阳性乔木,茶树(Camellia sinensis)是阴性灌木。这两种树种间作,形成针阔、乔灌两层树冠结构的茶园复合生态系统,可以改善茶树生态条件,提高茶叶的产量和品质。但间作存在胁地现象。一般认为这是上层树木的过度遮荫和根系间的竞争造成的。为了解这两种树种根系的分布状况和相互关系,并为间作茶园的合理配置和加强这种茶园的耕作管理提供依据,我们进行了湿地松与茶树间作根系分布状况的研究。     

东方法老蛛雌蛛的描述（蜘蛛目：跳蛛科）

报道采自甘肃文县的东方法老蛛雌蛛,为该种雌蛛的首次记述。     

An attempt to correlate brain areas containing melatonin-binding sites with rhythmic functions: a study in five hibernator species

High affinity melatonin-binding sites have been described, by means of autoradiography with 2-¹²⁵I-melatonin as the ligand, in more than 60 brain areas of about 20 mammalian species, with dramatic variations in the nature and number of labelled structures among the different species studied. As melatonin is involved in the synchronization of biological rhythms, we have tried to correlate the brain areas containing melatonin-binding sites with some rhythmic functions typical of give species. Therefore, we have studied the location of melatonin-binding sites in the complete brain of five long-day breeders with hibernation cycles, viz. one insectivore and four rodents. With the exception of the suprachiasmatic nuclei and the pars tuberalis of the pituitary, both of which contain binding sites in all five species, few reactive structures are common, even among species from the same family, e.g. the edible dormouse and the garden dormouse.     

东方次睾吸虫电镜研究(吸虫纲:后睾科)V.雌性生殖器官

东方次睾吸虫雌性生殖器官（卵巢、输卵管、卵黄－输卵管、卵模、梅氏腺和子宫）透射电镜 观察。卵巢内有不同成熟期的生殖细胞,成熟初级卵母细胞有几个靠近核的核仁样小聚体和许多沿 质膜的皮质颗粒。首次发现并描述卵巢和输卵管接合处（卵巢壶腹）的超微结构。输卵管上皮为纤 毛状。梅氏腺仅一种类型膜状小体细胞,经有微管支持的细小管道穿过卵模将膜状小体排入卵模腔 内。在卵黄－输卵管和卵模中有精子,卵模和子宫中有受精卵、虫卵（扫描电镜）：大小 ２６. ０５× １１．４６－１３．５５μｍ,卵盖直径６．２６－６. ８９μｐ,卵壳表面布满膜状隆起。文中对卵巢和梅氏腺的超微 结构特点进行了讨论。     

DOCA—Salt高血压大鼠模型的一种简易制备方法：DOCA硅胶管皮下埋入法

用外径４ｍｍ,内径２．５０ｍｍ的硅胶管制成长２５ｍｍ,管内填入ＤＯＣＡ１００ｍｇ,管壁钻有１０一１４个直径约３００μｍ微孔的药管,埋入雄性ＳＤ大鼠（１４０±９ｇ）右下腹皮下,摘除一侧肾脏,术后喂１％盐水。埋管后３周即可形成高血压,埋管后８周大鼠的收缩压达２３．３±０．３７ｋＰａ。而ＤＯＣＡ皮下注射组大鼠（１０ｍｇ／周）术后５周形成高血压,术后１３周大鼠的收缩压达２３．３±０．６６ｋＰａ。两组升压曲线回归系数（１．２９５和０．６９２）之间的差异有极显著性意义（Ｐ＜０．００１）。对照鼠的收缩压一直保持在正常水平（１６±０．１６ｋＰａ）。与ＤＯＣＡ皮下注射法相比,皮下埋管法具有两个显著优点：（１）升压速率较快,升压幅度较大;（２）方法简便可靠,重复性好。     

田林老山中山两类森林凋落物研究

田林老山中山两类森林凋落物研究梁宏温（广西农学院林学分院,南宁５３０００１）ＳｔｕｄｉｅｓｏｎｔｈｅＬｉｔｔｅｒｆａｌｌｏｆＴｗｏＦｏｒｅｓｔＴｙｐｃｓｉｎＭｉｄ—ＡｌｔｉｔｕｄｅｏｆＬａｏｓｈａｎＭｏｕｎｔａｉｎｉｎＴｉａｎｌｉｎＣｏｕｎｔｙ．￥Ｌ...     

东方蝾螈繁殖生态的研究

本文报道东方蝾螈(Cynops orientalis)的繁殖生态,内容有精巢分叶、精子形态、怀卵量、性征、性比、求偶、交配、纳精、产卵及孵化等,并对产卵场中性比的周年变化、精包形态、精子存活力及与蓝尾蝾螈的种间差异进行了观察和讨论。