赤霉素浸泡与层积时间对山樱种子萌发的影响

研究了层积前用不同浓度的赤霉素浸泡48 h以及层积时间对山樱(Cerasus serrulata Don.)种子萌发的影响.结果表明:山樱种子具有低温休眠的特性,未通过休眠的种子不发芽,通过低温层积能打破休眠,促进发芽.层积前用赤霉素浸泡能显著缩短层积时间,提高种子发芽率.在所有处理组合中,以1 500 mg/L赤霉素浸泡48 h后层积60 d和层积40 d两处理打破休眠效果最好,其种子发芽率分别达到92.2%和88.1%,极显著或显著地高于其它处理组合.清水浸种虽能在一定程度上促进种子的发芽,但效果并不明显.     

Hybrid drying with high-frequency heating and hot air under atmospheric pressure IV: water movement in <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> wood during high-frequency heating

 The relations among internal temperature, internal pressure, and moisture content distribution in sugi square lumber during high-frequency (HF) heating were determined to clarify the mechanism of water movement during the combination of HF heating and hot air exposure. Green sugi square lumbers were subjected to HF heating under atmospheric pressure. The water movement and pathways in the lumber during HF heating were also investigated. Results showed that internal pressure is the driving force of water movement. HF heating causes a rise in the internal temperature and internal pressure in sugi square lumber. Ordinarily, water in lumber evaporates from the surfaces of lumber during hot air drying. However, with HF heating the internal pressure is generated by the increased temperature, and liquid water is driven not only parallel to the grain but also perpendicular to the grain of the lumber. The ratio of the amount of liquid flow in the parallel and perpendicular directions ranged from 2 : 3 to 1 : 3. When the movement of water in the lumber was traced with a 0.5% aqueous solution of acid fuchsin, water was found to move through the lumber in the longitudinal direction and then flow in a direction perpendicular to the grain or in the radial and tangential directions. Received: June 15, 2001 / Accepted: February 8, 2002 Acknowledgment The authors thank Dr. O.R. Pulido, Institute of Wood Technology, Akita Prefectural University, for discussions and for proofreading this paper. Part of this research was presented at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001 Correspondence to:Y. Kawai     

The penetration rate of laser pulses transmitted from a small-footprint airborne LiDAR: a case study in closed canopy, middle-aged pure sugi (Cryptomeria japonica D. Don) and hinoki cypress (Chamaecyparis obtusa Sieb. et Zucc.) stands in Japan

Penetration rates of laser pulses transmitted from a small-footprint airborne light detection and ranging (LiDAR) system in closed-canopy, middle-aged (40–50 years old) hinoki cypress (Chamaecyparis obtusa Sieb. et Zucc.) and sugi (Cryptomeria japonica D. Don) plantations that had similar levels of canopy openness were studied. The number of transmitted pulses was 107 427 points/ha for the hinoki cypress stand and 122 883 points/ha for the sugi stand. The penetration rates of the first (P_f) and second pulses (P_s) that reached the ground were 0.1% and 1.0% in the hinoki cypress stand, and 2.6% and 5.5% in the sugi stand, respectively. Penetration rates for the total number of pulses (P_f+s) that reached the ground within each stand were 1.1% and 8.1%, respectively, and values for P_f+s, P_f, and P_s for sugi and hinoki cypress stands were significantly different (P < 0.001). The results of this study indicated that the generation of accurate digital terrain models in dense hinoki cypress stands with complex topographies using only the data from laser pulses with poor laser penetration rates is likely to be difficult.     

Water resources management of the southern rivers of Russia with reference to fisheries requirements

Water consumption from Russia's southern rivers has increased substantially in recent years as a consequence of intensified economic activity. The volume of irreversible river-flow withdrawal from the Azov Sea basin varies between 11 and 13 km³ year^1. The majority of the abstracted water is used for irrigation. By 1990, the decrease in discharge into the Caspian Sea was 41 km³ year^1. Withdrawals of water from the Kura, Terek, Ural and other rivers have so far exceeded the ecologically admissible limits and become critical. The paper discusses methodological approaches for the elaboration of standards for water withdrawal and ecologically safe discharges into the southern seas. New data are presented on the dynamics of fish abundance as a function of the hydrological characteristics of rivers and water salinity. The results of the system analysis and regressive modelling formed the basis of a programme to develop policies for water management for fisheries in the lower Don. The principles and criteria for water withdrawal under variable hydrological regimes for the rivers entering the Azov and the Caspian Seas should be tested for their applicability for other water bodies (e.g. rivers, water reservoirs and lakes).     

竹叶兰的无菌播种快繁技术研究

以竹叶兰种子为外植体进行无菌播种,成功诱导原球茎并再生植株,建立其快繁体系。试验结果表明：(1)1/2 MS＋香蕉泥30.0 g/L为最佳种子萌发与原球茎诱导培养基;(2)1/2 MS＋6-BA 1.0 mg/L＋NAA 0.1 mg/L＋香蕉泥30.0 g/L为最佳芽增殖培养基,且芽生长健壮;(3)1/2 MS＋IBA 0.5 mg/L为最适生根培养基。     

长春花4种提取物肝癌细胞毒活性的研究

用溶剂萃取法对长春花地上部分的95%乙醇提取物进行分段处理,以肝癌细胞系SMMC-7721为筛选模型,利用MTT法测定各提取物的体外肿瘤细胞毒活性,对长春花的肝癌细胞毒活性部位进行了筛选。结果表明：长春花乙醇总提取物和正丁醇提取物对体外肝癌细胞表现出较强的抑制活性,石油醚提取物﹑乙酸乙酯提取物和水提取物则没有活性。说明正丁醇提取物部分是长春花体外肝癌细胞毒活性部位。     

RAPD Marker Diversity Within and Among Natural Populations of the Clonal Tree Cryptomeria japonica D. Don.

Abstract

The Japanese cedar, Cryptomeria japonica D. Don., is one of the most important endemic species in Japan. A long history of heavy logging has resulted in natural populations being discontinuously distributed and scattered among small, restricted areas. An understanding of the patterns of genetic variability among and within populations of C. japonica is important for conserving the genetic resources of this economically important species. We studied genetic variation by random amplified polymorphic DNA (RAPD) markers in C. japonica of Kyoto prefecture, western Japan. A total of 398 plants sampled from six natural populations were analyzed by ten arbitrarily chosen decamer primers, resulting in 50 highly reproducible RAPD bands. Analysis of molecular variance partitionated the RAPD variation into the among- and within population components. The within-population component accounted for 93.75% of the variation. The among-population component accounted for only 6.25%. Indirect estimates of gene flow indicated that the average number of migrants exchanged among six populations per generation was 3.72. A Mantel test for each population did not yield significant correlations between geographic and genetic distances. The extent and distribution of C. japonica diversity in the Kyoto prefecture is in agreement with the conclusion that long-lived, wind-pollinated, out-crossing species with wide ranges retain a considerable amount of genetic diversity within populations and exhibit little genetic differentiation among populations.     

微波等离子体处理木材表面接枝甲基丙烯酸甲酯的XPS分析

应用X-射线光电子能谱(XPS)技术，对微波等离子体引发木材与甲基丙烯酸甲酯(MMA)发生接枝共聚反应前后的木材表面结构及物理化学特性进行了分析。分析表明：1)微波等离子体处理使木材表面O／C原子比增加，C1含量降低，而C2、C3含量增加，并有C4峰的出现，这表明经微波等离子体处理后木材表面产生了大量的含氧官能团或过氧化物；2)微波等离子体接枝材表面的O／C比有所增加，但介于素材与微波等离子体处理材之间，C18谱峰主要变化是强C4峰的出现，这表明木材表面产生了大量的O-C=O官能团；3)微波等离子体接枝材的O1／O2值基本接近1，大于素材(0．11)和微波等离子体处理材(0．21)的值，说明接枝材表面的C=O含量大幅度增大。以上结果表明木材表面接枝上了大量的MMA分子。     

薤软腐病的研究

薤软腐病是由胡萝卜软腐欧氏杆菌胡萝卜致病变种(Erwinia carotovorasub sp.carotovora)引起的。有病鳞茎和带菌土壤是大田发病的初侵染源,病菌通过伤口侵入寄主,导致组织腐烂,甚至全株死亡。经人工接种试验,该病菌至少能为害7科14种植物。在发病初期使用24%农用链霉素可溶性粉剂100~200mg·kg-1水溶液、25%叶枯宁可湿性粉剂600~900倍液和45%代森铵水剂600~900倍液等能有效控制病情发展。     

不同分离方法对黄杜鹃叶提取物灭蚜活性的影响

黄杜鹃(Rhododendron molle)叶提取物对桔二叉蚜(Toxoptera aurantii)有较强的毒杀作用。用水提醇沉法和醇提水沉法获得的提取物对蚜虫的致死中浓度(LC₅₀)分别为4 030 mg／L和5 791 mg／L。水提醇沉提取物的乙酸乙酯萃取物对桔二叉蚜的毒力较其他萃取物强,其LC50为1 949 mg／L,表明黄杜鹃叶含有的杀虫活性物质主要存在于乙酸乙酯萃取物中。对水提醇沉提取物进行硅藻土柱层析分离,得到的第3组分得率和灭蚜效果均优于氧化铝柱层析分离到的第3组分。