Plant-growth regulators derived from the sweetener stevioside

A series of isosteviol derivatives such as aromatic esters and amino acid amides were synthesized. Their effects on seed germination and root elongation of the crop plants, Capsicum annuum, Lens culinaris medicus, Lycopersicon esculentum, Trifollium spp. and Triticum vulgare, were studied. The derivatives could be arranged into four groups: (1) seed germination inhibitors (2) root elongation inhibitors (3) root elongation inducers (4) general inhibitors.     

Effect of arbuscular mycorrhizal fungi on the acclimatization of micropropagated banana plantlets

 The effect of arbuscular mycorrhizal fungi (AMF) on micropropagated banana plantlets was evaluated during the acclimatization period. Plants were inoculated with Acaulospora scrobiculata, Glomus clarum or Glomus etunicatum. After cultivation in a greenhouse for 3 months, height, leaf area, fresh weight and dry matter of root and shoots, level of AMF colonization, nutrient level, photosynthesis and transpiration rate, water potential and stomatal conductance were measured. The number of AMF spores produced in each treatment was also determined. Plantlets inoculated with AMF had greater height, leaf area and fresh weight of shoots and roots, as well as higher rates of photosynthesis and transpiration than controls. Plants inoculated with Glomus were superior in most of the evaluated parameters. Accepted: 24 May 1999     

Variability in tolerance to UV-B radiation among Beauveria spp. isolates

Solar radiation, particularly the UV-B component, negatively affects survival of entomopathogenic fungi in the field. In an effort to identify Beauveria spp. isolates with promise for use in biological control settings with high insolation, we examined 53 Beauveria bassiana isolates, 7 isolates of 4 other Beauveria spp. and Engyodontium albus (=Beauveria alba). The origins of these fungi varied widely as to host/substrate and country, but approximately 30% of these isolates were B. bassiana from ticks in Brazil. A preliminary trial with three B. bassiana isolates (Bb 19, CG 310 and CG 481) at several UV-B dosages indicated that 2h of weighted UV-B irradiance at 978mWm(-2) (providing a total dose of 7.04kJm(-2)) allowed separation of isolates into low, medium or high UV-B tolerance. This dose, therefore, was selected as a single dose to compare UV-B tolerances of all 60 Beauveria spp. isolates. There was high variability in tolerance to UV-B radiation among the B. bassiana isolates, ranging from virtually zero tolerance (e.g., Bb 03) to almost 80% tolerance (e.g., CG 228). In addition, surviving B. bassiana conidia demonstrated delayed germination; and this is likely to reduce virulence. Conidia of the other species were markedly more sensitive to UV-B, with E. albus (UFPE 3138) being the least UV-B tolerant. Among B. bassiana isolates originating from 0 degrees to 22 degrees latitudes, those from lower latitudes demonstrated statistically significant greater UV-B tolerances than those isolates from higher latitudes. Isolates from above 22 degrees , however, were unaffected by latitude of origin. A similar analysis based on host type did not indicate a correlation between original host and UV-B tolerance. The identification in this study of several B. bassiana isolates with relatively high UV-B tolerance will guide the selection of isolates for future arthropod microbial control experiments.     

悬铃木属植物果皮毛性状及其对小鼠肺部的致炎作用

观察了3种悬铃木聚合果的形态、坚果形态、聚合果上坚果数量、坚果上果皮毛数量、聚合果总果皮毛数量,比较了3种悬铃木聚合果的形态学差异,发现二球悬铃木的聚合果最大,聚合果上的坚果数量与坚果的果皮毛数量最多;采用石蜡切片染色观察和NaOH处理证明悬铃木果皮毛主要有果胶质、纤维素和木质素3种主要成分;通过用不同浓度粒级符合PM10大小的果皮毛对小白鼠进行支气管染毒试验,证明染毒后小鼠肺泡灌洗液中磷酸还原酶(ACP)含量升高,显示肺细胞受损;GSH-Px含量下降,显示小鼠肺部氧化和抗氧化系统失衡.试验结果证明,悬铃木果皮毛破碎后所形成的可吸入颗粒物PM10对小鼠的呼吸道具有致炎作用.     

新型数值分类软件X-Cluster的开发及应用

针对目前常用数值分类软件的不足,采用多种设计模式开发了新型数值分类软件X-C luster。该软件具有界面友好、操作方便、体积小、速度快、功能强大、应用范围广等特点,能够满足大多数情况下数值分类研究工作的需求,并在芽孢杆菌分类研究中得到了验证。     

Unusual glycoconjugates in the oesophagus of a tilapine polyhybrid

The aim of this work is to elucidate the glycoconjugate composition of the secretory products of the oesophageal mucous cells in a tilapine polyhybrid. Lectin histochemistry gave evidence of the presence of β-galactose, α-N-acetylgalactosamine and sialic acid residues in the terminal position. The majority of sialic acid belongs to short side chains; a few sialic acid residues are acetylated at the C₇ and/or C₈ and/or C₉ level. The heterogeneity of the carbohydrate chains may mask potential receptor sites for micro-organisms and hamper the formation of multiple bonds.     

福建红曲醋中产酸菌株的分离及鉴定

添加含有高浓度乙醇的红曲酒至福建传统红曲醋醋母中富集产酸菌株,采用高浓度乙醇平板,依据溶解圈指标从福建传统红曲醋液体循环工艺样品中分离出7株产酸菌株。综合菌株形态、生理生化实验以及16S r DNA序列测定等信息,确定这7株菌株分类地位为变形菌门(Proteobacteria)α-变形菌纲(Alphaproteobacteria)红螺菌目(Rhodospirillales)醋酸菌科(Acetobacteraceae)葡糖酸醋杆菌属(Gluconacetobacter),其中菌株Y5052、Y5054、Y5072、Y5092鉴定为斯氏葡糖酸醋杆菌(Gluconacetobacter swingsii);菌株Y5032、Y5033、Y5071鉴定为欧洲葡糖酸醋杆菌(Gluconacetobacter europaeus)。测定这些菌株的产酸能力,菌株Y5052产酸量最低,7 d达15 g/L;菌株Y5054产酸能力最强,7 d产酸量达57.0 g/L。     

卡马西平降解菌的筛选及降解特性研究

药品和个人护理品类污染物日益成为新兴污染物研究的重点, 药品卡马西平因具有多种药效被广泛使用, 在环境中频繁被检出, 且浓度较高, 不易去除, 通常作为环境中药品和个人护理品污染状况的指示化合物。本研究从某制药厂的污水处理厂中分离到一株细菌HY-7, 能以卡马西平为唯一碳源、氮源和能源生长, 通过生理生化以及16S rDNA、gyrB基因序列分析鉴定并命名为Acinetobacter sp. HY-7。该菌株生长和降解卡马西平的最适条件为25°C和pH 6.0, 经HPLC分析10 d内能将初始浓度为20 mg/L的卡马西平降解48%。菌株HY-7还能以邻苯二酚、吲哚、萘、蒽等芳香族化合物为唯一碳源生长。     

Forest succession in the subalpine region of Mt. Fuji,Japan

Subalpine forest succession was studied on Mt. Fuji, Japan, where various types of forests in different successional phases occur owing to volcanic action. Ninety stands were subjected to ordination using an index (SI) defined by the relative basal area and the life span of component woody species, and the cover of canopy layer of the sample stands. Two different sequences of sample stands were found. One was from deciduous scrubs, through Larix kaempferi forests and Abies forests, to Tsuga diversifolia forests, and the other from Abies-Tsuga thickets to Abies forests. Through analyses of the forest structure and composition, soil survey and identification of fallen logs, the former sequence was recognized as the primary sere and the latter as a regeneration sere following gap formation. During forest succession, basal area reached a maximum in the seral phase with a multi-layered structure. The Tsuga forests, whose understory is restricted to a moss layer, were regarded as the climax. The death or fall of Tsuga stems resulted in gaps, which were subsequently occupied by Abies-Tsuga thickets. The second Abies forests were distinguished from the ones in the primary sere by the occurrence of Dryopteris and Cacalia and the lack of Rhododendron in the understorey. Both Abies forest types included Tsuga saplings. Thus, a cyclic relation is supposed between Abies and Tsuga.Nomenclature follows Ohwi (1975) and Nakaike (1982) for vascular plants, Iwatsuki & Noguchi (1973) for mosses, Inoue (1981) for hepaticae, Kashiwadani (1981) for lichens, respectively. Abies veitchii, A. mariesii were lumped as Abies spp.I wish to express my sincere gratitude to Prof. Toshio Hamaya, Tokyo, for the cordial guidance and encouragement. I also thank Prof. M. Numata and Dr. M. Ohsawa, Chiba, Prof. K. Okutomi, Tokyo, Dr. K. Suzuki, Tokyo, Dr. M. Suzuki, Kanazawa, and Mr. H. Taoda, Kumamoto, for their valuable advice and discussions.