Influence of Saccharomyces cerevisiae strains on fermentation and flavor compounds of white wines made from cv. Emir grown in Central Anatolia,Turkey

The effect of inoculation with selected Saccharomyces cerevisiae strains was studied on fermentation and flavor compounds of wines made from Vitis vinifera L. cv. Emir grown in Central Anatolia, Turkey. Flavor compounds were analysed and identified by GC-FID and GC-MS, respectively. The total concentrations of flavor compounds did not increase with the addition of indigenous and commercial wine yeasts, but differences were noted in individual volatile compounds. Cluster and factor analyses of flavor compounds also showed that wines produced were different depending on the wine strain used. Wines were completely fermented to less than 1.4 g/l residual sugar. Yeasts other than S. cerevisiae survived longer than previously reported. Inoculation with selected strains increased the ethanol level. Journal of Industrial Microbiology & Biotechnology (2002) 29, 28–33 doi:10.1038/sj.jim.7000258 Received 11 July 2001/ Accepted in revised form 27 March 2002     

红江橙体胚发生及影响因素的研究

红江橙花后４周的幼果,直径约１ｃｍ左右,这时期的胚珠最适于胚性愈伤组织的诱导。以ＭＴ为基本培养基,加上适当浓度的ＩＡＡ、ＢＡ和ＭＥ可显著提高胚性愈伤组织诱导率。体胚发生,以ＭＴ＋ＩＡＡ０．１ｍｇ１－１＋ＢＡ（ＺＴ）１ｍｇ１－１培养基较好,能诱导产生正常体胚,且频率较高。胚性愈伤组织继代次数对体胚发生也有一定的影响,继代６次以内,胚性愈伤组织具有旺盛产生体胚能力;继代至第９次时,产生体胚的能力明显下降;至第１２代时,不能产生胚状体。成熟胚转换成小植株,以ＭＴ＋ＧＡ２ｍｇ１－１＋ＮＡＡ０．１ｍｇ１－１培养基成苗率最高。     

Vessel-diameter distribution in roots of grapevines (Vitis vinifera L. cv. Shiraz)

The distribution frequency patterns of diameter of xylem vessels and percentage of total predicted axial conductances were studied in 190-day and 212-day-old main roots of grapevine (Vitis vinifera L. cv. Shiraz) grown under well-watered and stressed conditions. The protoxylem were the first to mature and were responsible for most of the theoretical conductance in root segments between the tip and 2.5 cm from the tip. Some large xylem vessels retained cross walls and protoplasm up to 22.5 cm from the tip. Statistical tests using the Kolmogorov-Smirnov two sample test showed that the pattern of distribution frequency of xylem vessels classified in different diameter classes varied with distance from the root tip. The distribution frequency of xylem vessels was similar in both well-watered and stressed plants from the tip up to 15 cm from the tip. At distances further from the tip the distribution frequency of xylem vessels of well-watered plants was significantly different from that of stressed plants, with the former having more larger vessels than the latter. The pattern of vessel distribution frequency was different from that of percent total axial conductance (K_h) predicted with fewer large vessels carrying most of the axial flow.     

Osmotic adjustment, gas exchanges and chlorophyll fluorescence of a hexaploid triticale and its parental species under salt stress

The effect of salt stress (NaCl 85.7 or 110 mmol/L) was investigated in the triticale T300 and its parental species, Triticum dicoccum farrum (Triticum df) and Secale cereale cv. Petkus. Triticum df and T300 were more salt-tolerant than the rye (110 mmol/L NaCl was the highest concentration allowing rye growth to the three-leaf stage). Na+, K+ and Cl- ions accounted for almost half of the osmotic adjustment in Triticum df and T300, and up to 90% in rye. Salinity decreased the net photosynthesis and transpiration rates of the three cereals as compared to control plants, but induced no significant change in chlorophyll a fluorescence parameters. Water-use efficiency (WUE) increased with salinity. In the presence of 110 mmol/L NaCl, the K+/Na+ ratio decreased markedly in rye as compared to the other two cereals. Proline concentration, which increased in Triticum df and T300, could have protected membrane selectivity in favour of K+. Proline content remained low in rye, and increasing soluble sugar content did not appear to prevent competition between Na+ and K+. The salt sensitivity of rye could be due to low K+ uptake in the presence of a high NaCl concentration.     

Epiphytic microorganisms on strawberry plants (Fragaria ananassa cv. Elsanta): identification of bacterial isolates and analysis of their interaction with leaf surfaces

Epiphytic bacteria were isolated from strawberry plants cultivated in the field or in the greenhouse in order to investigate their interaction with leaf-surface transport properties. Colonization of lower leaf sides was higher on field-grown plants, whereas upper leaf sides were more densely colonized on plants cultivated in the greenhouse. Fungal isolates significantly contributed to total microbial biomass on leaf surfaces of greenhouse-grown strawberry plants, whereas these organisms were rarely abundant on field-grown plants. Microscopic investigations of bacteria in the phyllosphere revealed that the highest densities of bacteria were observed on living trichomes, which obviously provide a source of nutrients. Isolated strains were characterized by colony morphology, microscopy and histochemistry. About 324 isolated bacterial strains were grouped into 38 morphotypes. Of the morphotypes, 12 were identified by 16S rRNA gene sequencing. Dominating bacteria belonged to the genus Pseudomonas, Stenotrophomonas, Bacillus and Arthrobacter. Cuticular water permeability of isolated cuticular membranes and intact leaf disks was measured before and after treatment with one of the most prominent epiphytic bacteria, Pseudomonas rhizosphaerae. Results showed that cuticular transpiration was significantly increased by P. rhizosphaerae. This shows that leaf-surface properties, such as cuticular water permeability, can be influenced by bacteria, leading to improved habitable conditions in the phyllosphere.     

Dystroglycan contributes to the formation of multiple dystrophin-like complexes in brain

In muscle, dystrophin anchors a complex of proteins at the cell surface which includes alpha-dystroglycan, beta-dystroglycan, syntrophins and dystrobrevins. Mutations in the dystrophin gene lead to muscular dystrophy and mental retardation. In contrast to muscle, little is known about the localization and the molecular interactions of dystrophin and dystrophin associated proteins (DAPs) in brain. In the present study, we show that alpha-dystroglycan and dystrophin are localized to large neurones in cerebral cortex, hippocampus, cerebellum and spinal cord. Furthermore, we show that dystroglycan is a member of three distinct dystrophin-containing complexes. Two of these complexes contain syntrophin and both dystrophin and syntrophin are enriched in post-synaptic densities. These data suggest that dystrophin and DAPs may have a role in the organization of CNS synapses. Interestingly, the enrichment for syntrophin in post-synaptic densities is not affected in mice mutant for all dystrophin isoforms. Thus in the brain, unlike in muscle, the association of syntrophin with dystrophin is not crucial for the DAP complex which suggests that it may be associated with other proteins.     

外源ABA和GA3对红肉脐橙果皮主要色素含量变化的影响

测定了红肉脐橙果实发育期间果皮叶绿素和总类胡萝卜素含量的变化动态,并在果实转色前用不同浓度的外源ABA和GA₃处理后测定果皮色素含量的变化动态。结果表明,红肉脐橙果皮叶绿素总量于9月20日出现最大值(0.1469mg/gfw),总类胡萝卜素含量于12月20日达到最大值(0.0321mg/gfw);转色前用ABA处理后加速果皮叶绿素的降解,但抑制果皮类胡萝卜素的积累;转色前用GA₃处理后延缓果皮叶绿素的降解,并同样抑制果皮类胡萝卜素的积累,严重阻碍了果皮类胡萝卜素的合成。     

丛枝菌根真菌种间差异对柚苗营养生长及矿质含量的影响

在温室盆栽条件下研究了3种AM真菌Gigaspora margarita、Glomus mosseae和Glomus versiforme对长寿沙田柚(Citrus grandis cv. Changshou Shatian You)无菌苗营养生长及矿质含量的影响.结果表明,接种AM真菌的植株均有效地被感染;与对照相比,接种AM真菌能显著促进植株地上和地下部分生长,尤其促进了须根的生长,接种Glomus mosseae处理的主根长度比对照增加了22.7％,侧根数量增加了35.7％,须根数量和总长分别增加了160.8％和103.2％;接种AM真菌显著地提高了叶片的N、P、K、Ca、Mg、Zn、Cu和Mn含量,与对照相比,3种真菌处理的P含量分别增加了46.8％、88.7％和32.3％.3种AM真菌处理中,以接种Glomus mosseae处理营养生长最好,菌根依赖性最大,矿质元素N、P、K、Ca、Zn和Cu的含量最高,其效应顺序为Glomus mosseae＞Gigaspora margarita＞Glomus versiforme,可见,3种AM真菌对长寿沙田柚生长均有正效应,以Glomus mosseae最为显著,为长寿沙田柚适宜的优良菌种（株）.     

不同管理措施对毛竹林节肢动物群落结构和组成的影响

通过对不同管理措施下毛竹林Phyllostachys heterocycla cv. pubescens节肢动物群落的系统调查,研究了垦复施肥、垦复、劈草、化学除草和撂荒5种典型管理措施对群落结构和组成的影响。结果表明,与撂荒林相比,其他各管理措施均降低了群落竹冠层和林下层类群的丰富度,在林下层主要表现为蜘蛛目、膜翅目、半翅目和鞘翅目物种的减少,在竹冠层主要表现为膜翅目和鞘翅目物种的减少,这些减少的物种主要是偶见种（相对丰盛度小于0.01）。垦复施肥、垦复和劈草增加了林下层中性功能群和减少了捕食性功能群的个体数量,垦复施肥、垦复、劈草和化学除草增加了竹冠层捕食性功能群和减少了植食性功能群的个体数量。总体上各种管理措施均降低了林下层和提高了竹冠层类群的多样性和均匀度,但化学除草对林下层的影响较小,垦复对竹冠层的影响较小。长期撂荒和垦复林毛竹叶部害螨的优势度较高,长期撂荒、劈草和化学除草林蠕须盾蚧Kuwanaspis vermiformis的优势度较高,长期垦复施肥、垦复和劈草林刚竹毒蛾Pantana phyllostachysae的优势度较高,说明长期的单一管理措施可能导致特定种类害虫的暴发。因此提出在毛竹林的管理中,应避免长期采用单一方式,注重不同年份多种管理措施的轮换。     

灵武长枣果实质膜和液泡膜H~+-ATPase和H~+-PPase活性与果实糖分积累

以不同发育时期灵武长枣(Ziziphus jujuba cv.Lingwuchangzao)的果实为材料,通过测定与分析果肉组织中细胞质膜、液泡膜H+-ATPase和H+-PPase活性、果实糖分含量变化,研究了灵武长枣果实质膜、液泡膜H+-ATPase和H+-PPase活性与糖积累特性的关系。结果表明:(1)果实第二次快速生长期之前主要积累葡萄糖和果糖,之后果实迅速积累蔗糖,葡萄糖和果糖含量则逐渐下降,成熟期果实主要积累蔗糖。(2)在果实发育的缓慢生长期S1,质膜H+-ATPase活性最低;第一次快速生长期,质膜H+-ATPase活性最高;缓慢生长期S2,其活性降低;第二次快速生长期,质膜H+-ATPase活性升至次高;完熟期,质膜H+-ATPase活性下降幅度较大。(3)在果实发育过程中,液泡膜H+-ATPase和H+-PPase活性的变化趋势相似。缓慢生长期S1,液泡膜H+-ATPase和H+-PPase活性较低;从缓慢生长期S1至第一次快速生长期缓慢下降至最低;从第一次快速生长期开始,液泡膜H+-ATPase和H+-PPase活性呈现为逐渐增高的变化趋势;除第二次快速生长期以外,液泡膜H+-PPase活性始终高于H+-ATPase。由此推测,质膜H+-ATPase和液泡膜H+-ATPase、H+-PPase对灵武长枣果实糖分的跨膜次级转运起到重要的调控作用。