桉树抗寒生理研究进展

桉树是我国南方重要的速生用材树种。低温是限制桉树栽培的主要因素之一,研究低温胁迫下桉树的抗寒机理不仅对引种栽培具有重要的理论意义,而且对增加我国的木材产量具有一定的应用价值。对低温胁迫下桉树的细胞膜透性、保护酶活性、丙二醛含量、细胞膜脂肪酸含量、光合性能以及可溶性糖、可溶性蛋白和游离脯氨酸含量的变化进行综述,并提出未来桉树抗寒领域的研究热点为桉树抗寒生理指标与生态学特性的关系、抗寒锻炼和引种驯化、对抗寒生理指标的综合评价、信号转导和基因工程等。     

Compartmental changes in the contents of total lipid, lipid classes and their associated fatty acids in developing yolk-sac larvae of Atlantic halibut, Hippoglossus hippoglossus (L.)

Total lipid, lipid classes and their associated fatty acids have been measured in whole halibut, Hippoglossus hippoglossus (L.) larvae and in dissected animals separated into yolk and body compartments. At hatching the larval body contained 17 μg ind^?1 of lipid (11% of larval body dry weight), while the yolk contained 190 μg ind^?1. Phosphatidylcholine (PC) accounted for 57% of total yolk lipids while phosphatidylethanolamine (PE), triacylglycerol (TAG), cholesterol and sterol ester (SE) accounted for 12%, 12%, 9% and 6% respectively. The main fatty acids in the PC fraction were 22:6n-3 (25.6 μg ind^?1), 16:0 (19.2 μg ind^?1) and 20:5n-3 (12.6 μg ind^?1). Between hatch and 200 day-degrees post hatch (D°PH) a net decline in total lipids of 29% was seen. There seemed to be some, but relatively minor, changes in the relative composition of lipids in the yolk throughout development, which are indicative of a non-selective endocytotic bulk uptake of lipids from the yolk. Towards first-feeding there was a selective catabolism of PC and a net synthesis of PE in the developing body, resulting in a shift in the lipid class composition in the body compared with that of the yolk. The fatty acids released from lipid hydrolysis were mainly used as energy substrates by the growing halibut larvae; 22:6n-3 was quantitatively one of the most important fatty acid fuel in energy metabolism. At the same time 38% and 23% of the 22:6n-3 released from PC was retained by the PE and neutral lipids in the growing larval body respectively. Except for 20:5n-3 (2%, 14%) no similar retention was seen in any of the other fatty acids. The observed net synthesis of PE in developing yolk-sac larvae of Atlantic halibut and the preferential retention of 22:6n-3 into it, increasing from 28% at hatching to 45% at 200 D°PH, may point to a high biological value of this compound.     

Haematological and biochemical analyses of Atlantic salmon, Salmo solar L., suffering from coldwater vibriosis ('Hitra disease')

Abstract. Juvenile Atlantic salmon, Salmo salar L. were sampled from a commercial Norwegian fish farm during an outbreak of 'Hitra-disease'. One group of fish subjectively judged as healthy and another as diseased were defined on the basis of the classical apathetic behaviour seen in'Hitra-disease ď salmon. Haematological and biochemical analyses were carried out from blood and organs in 10 fish from each group. The diseased fish were severely anaemic. The blood indices MVC, MCH and MCHC indicated active erythropoiesis to compensate for the loss. Alkaline phosphatase (AP) activity, total protein, albumin, creatinine, triglycerides and total cholesterol were significantly reduced in the serum of diseased fish, while the activities of aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) showed normal and significantly increased values respectively. Liver and spleen weight relative to the body weight and the content of water and lipid in the liver were significantly elevated in diseased fish. Furthermore, the iron content of the spleen was increased, whereas the zinc content showed no changes. The branched-chain amino acids valine, leucine and isoleucine were significantly higher and serine significantly lower in muscle extracts of diseased fish.     

烤烟顶杈腐解液对烟草生长和相关生理指标的影响

以烤烟品种K326烟株为材料,采用漂浮育苗试验方法,研究了烤烟顶杈腐解液（腐解液浓度梯度为0.00,0.25,0.50,0.75,1.00 g/mL）对其生长的影响。结果表明：顶杈腐解液对烟草生物性状上表现为＂高抑低促＂的作用,0.25 g/mL的腐解液能促进烟草生长,而其他浓度的处理则对烟草生长产生一定程度的抑制作用,并随着浓度增大而增强;在生理生化指标上,腐解液对总叶绿素含量、烟草根系活力与硝酸还原酶活性都能产生抑制作用,抑制作用也随着浓度的增大而加强;烟草过氧化物酶活性和丙二醛含量两项抗逆性指标数据均高于对照组。     

全国水土保持生态修复类型分区研究

生态修复是水土保持工作的主要任务之一.因地制宜,分区实施水土保持生态修复,意义重大.在<全国水土保持生态修复分区研究>的基础上,对全国水土保持生态修复分区做了进一步研究.从增强地方编制及实施水土保持生态修复规划的可操作性的角度出发,以县为单位界定了4个一级生态修复类型区和13个二级生态修复类型区的边界,绘出了全国水土保持生态修复类型区图,阐述了各类型区的自然、经济和社会状况.     

绿色饲料添加剂糖萜素及其在动物生产中的应用

近年来,抗生素的大量使用和滥用造成了动物的抗病性降低,同时也危害到食品安全,使得残留在畜产品中的抗生素直接危害到人类的健康.糖萜紊作为一种安全、无毒、稳定的饲料添加剂,具有促进动物生长、增强动物免疫力等作用.是较理想的抗生素替代品.     

水稻外观品质稳定性分析及G×E互作与气候因子的关系

基于AMMI模型,研究了25个水稻品种外观品质性状与环境的交互作用,并对参试品种垩白品质性状的稳定性、G×E互作与气候因子的关系及气候生态适应性进行了探讨.结果表明,稻米长、宽及长宽比的G×E互作效应差异不显著,垩白率和垩白度的G×E互作效应达到了1%的显著水平.在此基础上将参试品种分为稳定性最好垩白适中、稳定性适中垩白较小及稳定性和垩白性状均较差三类.垩白品质性状的iPCA与水稻生育期内的气温、日照、降雨的相关分析表明气候因子是决定G×E互作的一项重要环境因子.据此得到不同品种对气候因子的最佳品质适应性,如品种V9和V24(沈农9819和0142)的垩白率对温度较低的环境,V23(盐优5858)的垩白度对相对寡照高温的环境具有特殊适应性,在实际生产中选择与这些品种有负向互作的地点可获得较低的稻米垩白率和垩白度.     

蓝浆果在贵州省的应用栽培区划与评价研究

对贵州省野生蓝浆果资源的自然分布和区系特征进行了调查研究,根据蓝浆果的栽培适应性,结合贵州省的自然气候条件进行了分析,采用植物种植区划法对引种成功的地区和区划推广种植的地区的气候进行比较。认为：贵州省黔东南、黔南、黔中是蓝浆果的适栽地区,黔北、黔东北及黔西北较适合栽培蓝浆果,并对蓝浆果在贵州省的推广栽培提出意见和建议。     

猪传染性胸膜肺炎放线杆菌溶血素的研究进展

猪传染性胸膜肺炎是由胸膜肺炎放线杆菌引起的一种呼吸道疾病。根据荚膜多糖和脂多糖抗原表位不同,将胸膜肺炎放线杆菌分为15个血清型,不同血清型的菌株毒力大小不同,致病性也有强弱之别。该菌的致病性与多种毒力因子密切相关,而溶血素是决定该病原菌致病性强弱的关键因素。本文主要就其溶血素的研究进展作综述。     

逆境条件对植物光合生理影响的研究

综述了光照、温度、气体、水分以及矿质元素等因素造成的逆境条件对植物光合生理的影响,并对该领域的研究前景进行了展望。