禾本科牧草在典型草原区的适应性研究

2001-2003年在内蒙古锡林郭勒盟太仆寺旗通过小区试验,对来自美国、加拿大和中国的21份禾本科牧草进行了物候期、产草量和种子产量的评价和适应性研究.结果表明,来自美国和中国的6份材料不仅适应性较强,而且产草量和种子产量也相对较高,可作为该地区人工草地建设和天然草场改良的优良种质材料.     

生态适应性在植物水生诱导上的运用

本文通过论述植物普遍存在的生态适应性与环境变化对适应性形成及进化上的影响,以及植物生态适应性形成过程中胁迫环境的重要性,分析了植物水生诱导过程中相关的生理生化及生态方面的变化规律,提出了利用人工环境模拟技术来促进植物通气组织形成的技术路线,形成一套完整可操作的植物水生诱变操作流程,并展现了植物水生诱变技术在生产、生活、生态上的广阔应用前景。     

Adaptability to drought in sugar beet cultivars

The effects of NaCl and polyethylene glycol (PEG) on superoxide dismutase (SOD) and peroxidase (P) activities, lipid peroxidation (LP) and proline content in seeds and leaves of drought tolerant (FC-506 and MS-100) and drought sensitive (MS-612 and MS-13) sugar beet cultivars were examined. After PEG and NaCl treatment in tolerant cultivars both in seeds and leaves SOD activity mainly increased, though P activity increased only in leaves of tolerant cultivars. In drought sensitive cultivars the decrease of SOD and P activity was mostly observed. LP increased in seeds and leaves of all examined cultivars. The proline content increased in the leaves of examined cultivars and was significantly higher in drought tolerant plants. On the other hand, in the seeds only slight increase in proline content was found. The results obtained indicated that drought tolerance could be correlated with high proline content and enzymatic defense against lipid peroxidation.     

Temperature Adaptability of Psychrotrophic Pseudomonas

The rate of oxidation of glucose and alanine at low temperatures by washed cells of psychrotrophic strains of Pseudomonas is related to growth temperature.     

6个品种樱花在北京地区的适应性研究

为丰富北京地区樱花种植品种,选择大渔樱(Cerasus×kanzakura ‘Tairyo-zakura’)、修善寺寒樱(Cerasus×kanzakura ‘Rubescens’)、阳春(C. spachiana ‘Yoshun’)、天之川(C. serrulata ‘Erecta’)、兰兰(C. serrulata ‘Ranran’)、红华(C. serrulata ‘Kouka’)等6个品种樱花进行实验性种植。在田间观测的基础上,测定低温胁迫下根系脱氢酶活性、枝条脯氨酸含量,高温胁迫下叶片的电导率、可溶性蛋白含量。结果表明,6个品种中,随着温度下降,6个品种樱花根系脱氢酶还原量、枝条脯氨酸含量均呈现先上升后下降的趋势。大渔樱、修善寺寒樱、兰兰在-10 ℃时脱氢酶活性与脯氨酸含量达到最大值,阳春、天之川、红华在-15 ℃脱氢酶活性与脯氨酸含量达到最大值。6个品种的叶片相对电导率,均随着温度的上升不断升高。而叶片可溶性蛋白含量变化趋势,品种间差异较大。阳春、天之川、红华在北京地区适应性良好,大渔樱、修善寺寒樱、兰兰可在小环境较好的区域栽植。     

附生植物生理生态适应性研究进展

附生植物是生活在其它植物体或残体上的特殊植物类群,大多生长于森林冠层,空间上远离地面土壤,在光能、水分和养分吸收方面具有明显的局限性。对附生植物的类群、分布、生态功能及对环境的适应性进行了综述,着重分析了附生植物在环境资源有限的生境中生长旺盛并占据重要生态位的原因。同时对今后的研究方向进行了展望,即更新附生植物数据库,明确附生植物水分和养分来源及利用策略,加强对附生植物开发利用及资源恢复重建的研究。     

贵州4个蓝莓品种的海拔适应性研究

为了探讨蓝莓对贵州山林环境的适应特性,选择贵州低海拔(800 m)、中海拔(1100 m)和高海拔(2000 m) 3个区域栽培的兔眼蓝莓Vaccinium ashei‘灿烂’、‘圆蓝’和高丛蓝莓V. corymbosum‘蓝雨’、‘莱克西’等4 个品种,测定分析其叶片和果实的相关生理指标。结果表明,4 个品种的丙二醛(MDA)含量和过氧化氢酶(CAT)活性均随海拔升高呈显著下降趋势,叶片相对电导率、过氧化物酶(POD)活性、超氧化物歧化酶(SOD)活性和总叶绿素含量则随海拔上升呈显著增加趋势;而在相同海拔区域中,‘灿烂’的叶片相对电导率和MDA 含量是4 个品种中最低的;其SOD 活性则在各海拔区域中是最高。在蓝莓果实品质方面,高海拔地区的VC 含量以‘莱克西’为最高,‘灿烂’最低,低海拔和中海拔地区则以‘圆蓝’为最高,‘蓝雨’最低;花青素含量依次为‘圆蓝’＞‘灿烂’＞‘莱克西’＞‘蓝雨’,蓝莓果实单重表现为‘莱克西’＞‘灿烂’＞‘圆蓝’＞‘蓝雨’,均具有一定的规律性;‘圆蓝’的糖酸比在低、中海拔区均为最高,在高海拔区则以‘灿烂’为最高。以上说明4 个蓝莓品种在贵州不同海拔地区中抗性指标和叶绿素的变化表现出一定的抗逆境能力,是对环境的适应性表现;其中,‘灿烂’的适应性最好,果粒较大,在高海拔区糖酸比最高;‘圆蓝’的适应性弱于‘灿烂’和‘莱克西’,果粒较小,糖酸比在中低海拔区域最高,适口性最好,VC 和花青素含量最高。     

Steroid-transforming enzymes in fungi

Fungal species are a very important source of many different enzymes, and the ability of fungi to transform steroids has been used for several decades in the production of compounds with a sterane skeleton. Here, we review the characterised and/or purified enzymes for steroid transformations, dividing them into two groups: (i) enzymes of the ergosterol biosynthetic pathway, including data for, e.g. ERG11 (14α-demethylase), ERG6 (C-24 methyltransferase), ERG5 (C-22 desaturase) and ERG4 (C-24 reductase); and (ii) the other steroid-transforming enzymes, including different hydroxylases (7α-, 11α-, 11β-, 14α-hydroxylase), oxidoreductases (5α-reductase, 3β-hydroxysteroid dehydrogenase/isomerase, 17β-hydroxysteroid dehydrogenase, C-1/C-2 dehydrogenase) and C-17-C-20 lyase. The substrate specificities of these enzymes, their cellular localisation, their association with protein super-families, and their potential applications are discussed. Article from a special issue on steroids and microorganisms.     

Pectolytic enzymes in Rhizobium

A sensitive pectin agar plate assay was used to demonstrate low levels of pectolytic enzymes in infective and noninfective strains of Rhizobium. The possible relation of this characteristic to legume infection is discussed.     

Hydrolytic enzymes in aquaticHyphomycetes

Thirty-five species of aquatic hyphomycetes were screened for the ability to degrade polysaccharides and some other obvious components of plant tissues. Under laboratory conditions, nearly all strains tested were able to degrade lignin, pectin, cellulose and protein, as well as the secondary products of cellulose, xylan and amylose decomposition.     

Immobilized enzymes in analysis

The sensitivity and specificity of enzyme reactions has led to the widespread use of enzymes as reagents in analysis. This article surveys the applications of immobilized enzymes in clinical analysis with particular emphasis on bioluminescent and chemiluminescent assays and test devices intended for use outside the main clinical laboratory.