赣南红壤侵蚀区植被退化和恢复演替的初步研究

在对赣南典型红壤侵蚀区进行调查的基础上，结合有关资料论述了赣南红壤侵蚀区植被退化和恢复演替的基本规律，并结合退化和恢复过程提出了重要植被的措施。     

Phytophthora disease of alder (Alnus glutinosa) in France: investigations between 1995 and 1999

A severe decline of alder associated with an undescribed Phytophthora species was identified for the first time in England in 1993. No generalized decline of alder was reported in France before 1990. The first diebacks and mortalities of common alder were observed at the beginning of the 1990s, but the so‐called alder Phytophthora was not isolated in France until 1996. First, a synthesis about alder declines that were known in France before 1995 is presented. Then, a survey was established in north‐eastern France; 108 sites were visited and the alder Phytophthora was isolated from 57 of them. All the main rivers were found to be affected and damage levels are significant along some of them. The frequency of the alder Phytophthora and other fungi isolated from declining alders is discussed. Finally, information on other alder declines in France is presented region by region, and a map summarizes the known distribution of the disease. The alder Phytophthora is quite common and widespread in France, with western and north‐eastern France being especially affected; however, the number of diseased or dead trees varies greatly from one site to another. All records are from Alnus glutinosa; other Alnus species were seldom seen in the surveys.     

热带松树种、种源引种试验初报

地处南亚热带的福建省长泰岩溪国有林场引种 5种热带松树的 7a栽培试验表明 :湿地松×加勒比松F1、F2 代生长均优于马尾松、湿地松 ;台库努曼松、马克西姆松与湿地松持平 ,各种源间初显差异。卵果松生长虽好 ,但抗逆能力差 ;墨西哥松基本不能适应新的环境     

Methods for isolating the alder Phytophthora

Phytophthora disease of alder (Alnus spp.) is now widespread in Europe. In France, difficulties were initially encountered in attempts to isolate the pathogen from necrotic bark tissue but, with experience, a high degree of success was achieved by direct plating onto agar media. Both corn meal agar and a selective medium derived from PARBHy were satisfactory. Success depended largely on the activity of the fungus in the bark tissue and some evidence was obtained that this varied from year to year. However, autumn was found to be a generally good period for isolation. It is possible to store collected samples at 7 ± 4°C for some days. The alder Phytophthora was isolated from the water of two rivers with a baiting method using alder twigs but the efficiency of the method was low.     

谈应用Photoshop cs软件绘制林业规划设计图的方法

介绍利用Photoshop CS软件绘制林业规划设计图,方法时尚、便于掌握、色彩鲜艳、成本低和效率高。在使用中,注意电脑系统、相关设备的配置;绘制方法和手段要正确;掌握一些技巧,才能充分发挥该软件的优越性,得到高质量的林业规划设计图。     

In Vitro Compaction of Germinal Vesicle Chromatin is Beneficial to Survival of Vitrified Cat Oocytes

The immature cat oocyte contains a large-sized germinal vesicle (GV) with decondensed chromatin that is highly susceptible to cryo-damage. The aim of the study was to explore an alternative to conventional cryopreservation by examining the influence of GV chromatin compaction using resveratrol (Res) exposure (a histone deacetylase enhancer) on oocyte survival during vitrification. In Experiment 1, denuded oocytes were exposed to 0, 0.5, 1.0 or 1.5 mmol/l Res for 1.5 h and then evaluated for chromatin structure or cultured to assess oocyte meiotic and developmental competence in vitro . Exposure to 1.0 or 1.5 mmol/l Res induced complete GV chromatin deacetylation and the most significant compaction. Compared to other treatments, the 1.5 mmol/l Res concentration compromised the oocyte ability to achieve metaphase II (MII) or to form a blastocyst. In Experiment 2, denuded oocytes were exposed to Res as in Experiment 1 and cultured in vitro either directly (fresh) or after vitrification. Both oocyte types then were assessed for meiotic competence, fertilizability and ability to form embryos. Vitrification exerted an overall negative influence on oocyte meiotic and developmental competence. However, ability to reach MII, achieve early first cleavage, and develop to an advanced embryo stage (8–16 cells) was improved in vitrified oocytes previously exposed to 1.0 mmol/l Res compared to all counterpart treatments. In summary, results reveal that transient epigenetic modifications associated with GV chromatin compaction induced by Res is fully reversible and beneficial to oocyte survival during vitrification. This approach has allowed the production of the first cat embryos from vitrified immature oocytes.