六种固氮蓝藻提取液对玉米的促长作用和提取液成分比较

本文用六种固氮蓝藻的提取液处理玉米种子,同时对其提取液氨基酸组成和碳水化合物与维生素Ｂ１２的含量进行了分析。结果表明固氮鱼腥藻ＨＢ６８６（ＡｎａｂａｅｎａａｚｏｔｉｃａＨＢ６８６）、球孢鱼腥藻ＨＢ１０１７（Ａ．ｓｐｈａｅｒｉｃａＨＢ１０１７）、多变鱼腥藻ＨＢ１０５８（Ａ．ｖａｒｉａｂｉｌｉｓＨＢ１０５８）和小单歧藻ＨＢＴＴ（ＴｏｌｙｐｏｔｈｒｉｘｔｅｎｕｉｓＨＢＴＴ）的提取液中氨基酸、碳水化合物和维生素Ｂ１２的含量高于鱼腥藻ＳＰ．ＨＢ１０４２（Ａｎａｂａｅｎａｓｐ．ＨＢ１０４２）和繁育管链藻ＨＢ３８（ＡｕｌｏｓｉｒａｆｅｒｔｉｌｉｓｓｉｍａＨＢ３８）。同时,促进玉米种子萌发和幼苗生长的效果前四种藻较好,后两种则较差。     

水华杀藻微生物的分离与分子生物学鉴定

正除藻方法一般分为工程物理方法、化学药剂法和生物方法三大类。作为庞大的富营养化湖泊的藻类控制技术,利用工程物理方法和化学药剂法显然是行不通的,对环境友好的生物控藻技术受到越来越多的关注,国内外许多富营养化湖泊水华的控藻技术的研究热点转向生物控藻技术。在利用生物控藻上,目前主要有三个方面,一是以鱼类控制藻类的生长;二是以水生高等植物控制水体富营养盐及藻类; 三是以微生物来控制藻类的生长。其中由于微生物易于繁殖的特点,使得微生物控藻是生物控藻里最有前途的一种控藻方式。这些杀藻微生物主要包括细菌(溶藻细菌)、病毒 (噬藻体)、原生动物、真菌和放线菌等五类。国内外对杀藻微生物的分离和鉴定有一些报道,但都不够系统和全面, 本文以本实验室的工作为基础,较全面、系统地介绍前三类水华杀藻微生物的分离与纯化及其分子生物学鉴定方法。       

甜瓜细菌性斑点病拮抗菌P-13的鉴定及其抑菌物质的初步研究

从新疆甜瓜根际土壤中分离到1株甜瓜细菌性斑点病拮抗放线菌P-13, 根据其形态学、生理特征和16S rRNA序列分析, 鉴定该菌株为娄彻氏链霉菌(Streptomyces rochei)。琼脂扩散法生物活性研究表明, 其发酵液对细菌性果腐病菌(Acidovorax avenae subsp. citrull)BFB、细菌性角斑病菌(Pseudomonas syringae pv. Lachrymans)P4的抑菌圈直径分别为19 mm和17 mm以上; 发酵液中抑菌物质主要为胞外代谢物, 不溶于石油醚, 乙醚, 乙酸乙酯等有机溶剂。在100°C处理10 min、pH 6处理6 h或紫外线照射7 h, 该物质抑菌活性不变。纸层析结果表明, 该物质主要为碱性水溶性物质。     

鱼腥藻提取液对水稻生长发育和产量的促进作用

以田间小区试验和大区产量直接对比的方法研究了鱼腥藻提取认对水稻幼苗生长和产量以及产量构成要素的影响,并探讨了方便有效且适宜于大田使用的方法。用藻液处理后水稻幼苗增高,根数、根长增加,分蘖能力增强,秧龄提前,叶面积明显加大。水稻成熟后除株高比对照略有下降外,各项产量构成要素如粒数、粒重、有效分蘖数、植株干重、千粒重、穗长等都优于对照组,但增产幅度随水稻品种和处理方式不同而异。大田使用时以１％鱼腥藻提     

植物生长物质在胚培养法挽救陈年小麦种质中的作用

以陈年小麦离体胚为外植体,MS培养基为基本培养基,附加5种植物生长物质2,4-D、NAA、KT、6-BA、GA3进行单因子和正交试验,研究植物生长物质在陈年小麦离体胚萌发中的作用。单因子试验结果表明：单独使用6-BA 1．0mg／L、GA3 2．5mg/L均能在一定程度上促进陈年小麦离体胚出芽和生根,出芽率分别为70．0％和77．5％,比对照分别提高了21．7％和29．2％;生根率分别为63．3％和72．2％,比对照分别提高了21．3％和30．2％。正交试验结果显示GA3对陈年小麦离体胚的萌发影响显著,最佳植物生长物质组合为2,4-D2．0mg／L NAA 1．1mg／L 6-BA0．5mg/L GA3 4．0mg/L,出芽率为82．5％,生根率为60．0％,比对照分别提高了32．5％和17．5％。     

生防菌株HG18基因组信息分析与抗菌功能基因挖掘

贝莱斯芽胞杆菌（Bacillus velezensis）HG18是1株低温生防菌株,能够分泌抗菌物质。为挖掘和利用其抗菌功能基因,服务农业生产,采用二、三代相结合测序技术,对其进行全基因组测序,获得菌株完整基因组序列。基因组全长4 461 844 bp,包含一个染色体和一个质粒,GC含量44.06%,编码4 643个基因,编码基因总长度3 893 994 bp,占基因组87.27%。发现6个几丁质降解相关基因,2个葡聚糖酶基因和1个壳聚糖酶基因,2个脂肽类抗菌物质芬芥素与表面活性素合成基因簇,2个细菌素subtilin和bacillolysin合成基因。研究为提高抗菌物质产量的菌株定向遗传改造以及植物抗病育种提供基因资源。     

Influence of environmental factors on content and composition of essential oil from common juniper ripe berry cones (Juniperus communis L.)

Abstract

The present study evaluated the influence of some environmental factors on the quantity and composition of essential oil (EO) in ripe berry cones of Juniperus communis L. The berry cones were collected from juniper shrubs growing wild at five localities of north-east Slovakia during the years 2012–2014. The EO yield ranged from 0.4 to 1.9%, depending on the locality and year. In the EO, eight monoterpenes (α-pinene, β-pinene, β-myrcene, sabinene, limonene, terpinene-4-ol, borneol, bornylacetate) and one sesquiterpene (β-caryophyllene) were identified. The dominant component was the monoterpene α-pinene, ranging from 31.0 to 49.0%. The amount and composition of the EO was affected by soil composition (content of humus and pH) and topographic environmental factors, including air temperature and precipitation. According to the composition of the EO, the studied juniper shrubs belong to the α-pinene chemotype.     

In vitro effects of bisphenol A on the quality parameters,oxidative stress,DNA integrity and adenosine triphosphate content in sterlet (Acipenser ruthenus) spermatozoa

Among endocrine disruptors, the xenoestrogen bisphenol A (BPA) deserves particular attention due to widespread human exposure. Besides hormonal effects, BPA has been suspected to be responsible for adverse effect on reproductive ability of various species. In the present study the effect of BPA on the quality parameters, oxidative stress, the DNA integrity and intracellular ATP content of sterlet (Acipenser ruthenus) spermatozoa were investigated in vitro. Fish spermatozoa were exposed to concentrations of BPA possibly occurring in nature (0.5, 1.75, 2.5, 5 and 10 μg/L) for 2 h. Results revealed that BPA significantly decreased spermatozoa motility and velocity of spermatozoa at concentration of BPA 2.5–10 μg/L. Significant positive correlation (r = 0.713, P < 0.05) was found between percent motile spermatozoa and ATP content. Oxidative stress was observed at concentrations 1.75–10 μg/L, as reflected by significantly higher levels of protein and lipid oxidation and superoxide dismutase activity. Intracellular ATP content of spermatozoa decreased with increasing concentrations of BPA. A dramatic increase in DNA fragmentation expressed as percent tail DNA (2.2% ± 0.46) and Olive tail moment (0.37 ± 0.09 arbitrary units) was recorded at concentrations of 1.75 μg/L and above. The present study confirms that concentrations of BPA that can be encountered in nature are capable to induce oxidative stress, leading to impaired sperm quality, DNA fragmentation and intracellular ATP content.     

Characterization and removal of biofouling from reverse osmosis membranes (ROMs) from a desalination plant in Northern Chile,using Alteromonas sp. Ni1-LEM supernatant

Abstract

Biofouling control in reverse osmosis membranes (ROMs) is challenging due to the high cost of treatments, and reduction in the life of ROMs. This study characterizes the biofouling in the ROMs from a desalination plant and reports its effective removal using the supernatant obtained from Alteromonas sp. strain Ni1-LEM. The characterization of the bacterial community revealed that the most abundant taxa in ROMs were the genera Fulvivirga and Pseudoalteromonas, and unclassified species of the families Flavobacteriaceae and Sphingomonadaceae. This bacterial community significantly decreased upon treatment with the supernatant from Alteromonas sp. Ni1-LEM, resulting in the prevalence of the genus Pseudoalteromonas. Furthermore, this bacterial supernatant significantly inhibited cell adhesion of seven benthic microalgae isolated from ROMs as well as promoting cell detachment of the existing microbial biofilms. The study showed that the extracellular supernatant modified the conformation of extracellular polymeric substances (EPS) in the biofouling of ROMs without any biocidal effects.     

水稻Rop基因OsRac5表达特性

Rop在植物生长、发育、免疫及环境信号应答等多种生物学过程中具有重要作用。已有研究显示水稻Rop基因OsRac5可能与育性控制有关,但是该基因的表达特性,以及非生物胁迫和植物生长物质对其表达的影响尚不清楚。本文采用qRT-PCR技术检测了OsRac5在水稻生长发育过程中、非生物胁迫以及植物生长物质处理条件下的表达特性,结果显示OsRac5在水稻生长发育过程中在多种组织广泛表达,尤其在根和雌雄蕊形成期的幼穗中高表达;干旱、高盐和低温等非生物胁迫均能诱导OsRac5表达;ABA、GAs、6-BA等植物生长物质能上调OsRac5基因表达,提示该基因与水稻幼穗发育、抗逆性及细胞生长等过程相关。