oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

时间不限

2017 ( 6 )

2016 ( 14 )

2015 ( 99 )

2014 ( 165 )

自定义范围…

匹配条件: “Monica SIPOS” ,找到相关结果约3235条。
列表显示的所有文章,均可免费获取
第1页/共3235条
每页显示
Liquid Nitrogen (-196°C) effect under pollen of some cultured or ornamental species
Monica SIPOS,Sabina GLIGOR
Analele Universitatii din Oradea, Fascicula Biologie , 2006,
Abstract: The criopreservation involve the stock of the vegetal material at low temperatures (-196°C) in liquid nitrogen, in thermal conditions in which the division of cells and metabolic processes slow down, thus that the samplings may be conserved for long periods without suffering any genetic modifications. This stock technique is applied till present only on 80 vegetal species, keeping their seeds and vitrocultures preponderantly; researches were made regarding the maintenance of pollen in liquid nitrogen.The mature pollen, able to resist a higher degree of desiccation, may be conserved at low temperatures, without criopreservation. It was made researches on criopreservation of rise, maize, wheat, roses, sun flower and soy pollen. Our study purpose was to follow the impact of liquid nitrogen (-196°C) about on viability of some cultured and ornamental species. The designed time of criopreservation it was 30 minutes and 7 days, using the TTC (tripheniltetrazole chloride) method which allows testing the viability of vegetal material based on dehydrogenase activity.It was observed at Petunia hybrida species, that the pollen viability was low - in relevance with the witness represented from the pollen which was not resigned to the nitrogen liquid treatment - between percentage limits of 3.5-8%, in the case when the vegetal material was submersed 30 minutes in liquid nitrogen and 7.5-14.5% 7 days at (-196°C). The submersing of Nicotiana alata var. grandiflora species at 7 days, determined a low viability with 11.53%. The following two studied species Cucurbita and Hosta were proved to be the most resistant at submersing and maintenance in liquid nitrogen. The most affected pollen was Campsis radicans species. At Datura stramonium species was observed 2.59% a low viability of pollen, after 30 minutes of liquid nitrogen treatment, was 19.56%, after 7 days of submersing, the most pollen granules losing completely their viability.
Anatomy of the vegetative organs at Syngonium podophyllum Schott.
Monica SIPOS,Anamaria TRIF
Analele Universitatii din Oradea, Fascicula Biologie , 2009,
Abstract: This article has as an objective establishing the structure of the vegetative organs at Syngonium podophyllum. The structure is specific for herbaceous monocotyledonous: root has a primary structure, the stem primary structure is an intermediary form between an aerial stem and a rhizome (the presence in a fundamental parenchyma of the colaterally closed vascular bundles and the leptocentric ones). The leaf petiole has the suberified epidermis. It is characterised by the colaterally closed vascular bundles disposed peripherically and extremely well protected by the sclerenchyma and in the centre of the petiole, in the fundamental parenchyma, the same type of fascicles are placed. The middrib has a structure similar to that of the petiole. The leaf mesophyll is homogenous. The parenchyma of aerial vegetative organs of this species is crossed by aeripherous channels and their cells contain calcium oxalate crystals. The leaf is amphistomatic, the stomatic complexes are an amarilidaceous type, tetracitic or hexacitic.
The allelopathic effect of the black nut leaves (Juglans nigra L.) over the species of moon – raddish (Raphanus sativus L.) and white mustard (Sinapis alba L.)
Sorina CORBU,Monica SIPOS
Analele Universitatii din Oradea, Fascicula Biologie , 2006,
Abstract: The present experiment is a research on the effect of the allelopathic substances in the leaves of the black nut (Juglans nigra L.) over the species of white mustard (Sinapis alba L.) and the moon – raddish (Raphanus sativus L.). We have prepared a watery extract of a concentration of 5, 15, 25, 50, 75 and 100% from the leaves in different seasons (spring, autumn and winter). The watery extract presents an inhibitory effect over the germination and growth of the plants subdued to experiments, especialy over the leaves collected in spring.
Relationships between enzymatic activities and chemical indicators in a brown luvic soil
Alina Dora SAMUEL,Monica SIPOS
Analele Universitatii din Oradea, Fascicula Biologie , 2006,
Abstract: Actual and potential dehydrogenase and phosphatase activities and nitrate, ammonium and mobile phosphorus contents were determined in the 0–20–, 20–40– and 40–60–cm layers of a brown luvic soil submitted to a complex tillage and crop rotation experiment.Each activity and each chemical content in both non-tilled and conventionally tilled soil under crops of both rotations decreased with increasing sampling depth. It was found that no-till – in comparison with conventional tillage – resulted in significantly higher soil enzymatic activities and nitrate, ammonium and mobile phosphorus contents in the 0–20– and in significantly lower activities and chemical contents in the deeper layers. The soil under maize or wheat was more enzyme-active in the 6– than in the 2–crop rotation. In the 2–crop rotation, higher enzymatic activities were registered under wheat than under maize; nitrate and ammonium contents were significantly higher under wheat excepting mobile phosphorus content. In the 6–crop rotation, higher enzymatic activities were registered under wheat; nitrate and mobile phosphorus contents were significantly higher under maize, while ammonium content was significantly higher under wheat. There were positive correlations between enzymatic activities and chemical indicators under each crop of both rotations.
Peroxidases activity in the embryos of germinated barley cariopses, after grain cryopreservation
Monica Angela SIPOS,Dorina CACHITA-COSMA
Analele Universitatii din Oradea, Fascicula Biologie , 2009,
Abstract: This study following the peroxidase activity (PA) in the embryos of germinated barley caryopses (Hordeum vulgare L.), after 20, 30 and 44 hours of germination. The experimental variants were represented by grains that have been frozen in liquid nitrogen (LN) (-196oC) for variable periods of time (5 minutes, 1 hour, 1 day, 1 week or 1 month). The results were represented in relation with the same parameter registered of the control lots (embryos of caryopses that were not subject of the treatment with LN). In all situations PA in the embryos was characterized especially by statistically insignificant inhibitions. The inhibitions of PA with statistical relevance were registered at 20 hours of germination, in the case of the experimental variants of 5 minutes, 1 hour and 1 day in LN. These results reveals a very well growth of the barley embryos after grains cryopreservation.
Roots and leafs hysto-anatomy of Cymbidium hybridum cultivated in vitro” and ex vitro”
Adriana PETRUS-VANCEA,Monica SIPOS
Analele Universitatii din Oradea, Fascicula Biologie , 2009,
Abstract: In this experiment we tried to found structural differences of Cymbidium hybridum roots and leaflets depending on culture conditions (“in vivo”, “in vitro” or “ex vitro”). At the end of the experiment we concluded that there are no structural differences between plants, except the normal ontogenetic changes. So, at the level of “in vivo” roots were observed many conductive fascicle, comparatively with “in vitro” or “ex vitro” roots, and at the “in vivo” and the “ex vitro” roots structure was identified the methaxylem, while, at the “in vivo” roots, this elements does not appear. The vitro- and exvitroleaflets mark a low chloroplast density, comparatively with control lots (“in vivo” cultivated leafs).
Influence of green manure fertilization on soil enzyme activities and other soil properties
Alina Dora SAMUEL,Monica SIPOS,Camelia DUSA
Analele Universitatii din Oradea, Fascicula Biologie , 2007,
Abstract: Agricultural practices that improve agricultural sustainability are needed particularly for brown luvic soil. Soil enzyme activities can provide information on how soil management is affecting the processes in soil such as decomposition and nutrient cycling. Soil enzyme activities (actual and potential dehydrogenase, catalase, acid and alkaline phosphatase) were determined in the 0–10, 10–20, and 20–30 cm layers of a brown luvic soil submitted to a complex fertilization experiment with different types of green manure. It was found that each activity decreased with increasing sampling depth. It should be emphasized that green-manuring of maize led to a significant increase in each of the five enzymatic activities determined. The enzymatic indicators of soil quality calculated from the values of enzymatic activities showed the order: lupinus + rape + oat > lupinus > vetch + oat + ryegrass > lupinus + oat + vetch > unfertilized plot. This order means that by determination of enzymatic activities valuable information can be obtained regarding fertility status of soils. There were significant correlations of soil enzyme activities with physical properties.
Histo-anatomy of the stem of Solanum tuberosum L.
Monica SIPOS,Manuela ILEA,Iosif MOLNAR,Daniel BUNTA
Analele Universitatii din Oradea, Fascicula Biologie , 2008,
Abstract: The paper reveals the anatomical structure of the stem of Solanum tuberosum L. in the incipient stages of the ontogenetic development (the popular denomination sprout”). Cross sections of the stem of this species were performed. The appearance of the secondary structure – even in this early ontogenetic stage – was confirmed by the presence of the cambium and the tissues generated by this. As a result, at the potato, the purely primary structure of the stem is of a short duration.
Histo-anatomical and histogenetic aspects in the stem and root of Chelidonium majus L.
Monica SIPOS,Iosif MOLNAR,Manuela ILEA,Dorina GURAU
Analele Universitatii din Oradea, Fascicula Biologie , 2008,
Abstract: The present study focuses on aspects of anatomy and histogenesis in the root and stem of common celandine (Chelidonium majus L.). The stem is annual, having a primary structure. It is to be noticed the depositing parenchyma within the medullar rays and around the vascular bundles. The secretory tissue from the near vicinity of the primary phloem gets together with this in the composition of the collateral vascular bundles. The chlorenchyma initially present in the structure of the common celandine stem shall be subsequently replaced by depositing and mechanic tissues. The primary perennial root has a diarch secondary structure. This structure is due to the functioning of the cambium and the phellogen along several years. The secondary phloem is a deposit for the amyloplasts, there being present here several laticifers. The ritidoma is well represented, black in colour, also rich in laticifers. The secondary roots have a medullar origin and disticha distribution.
Growth of the triticale plantlets (x Triticosecale Wittm.) after cariopses criopreservation
Monica SIPOS,Dorina CACHITA-COSMA,Dorina GURAU
Analele Universitatii din Oradea, Fascicula Biologie , 2007,
Abstract: Our research followed the growth of the triticale plantlets, in first 6 days of germination, after cariopses (with 6.89% degree of humidity) storage by immersion in liquid nitrogen (-196oC), for variable periods of time: 5 minutes, 1 hour, 1 day, 1 week or 1 month, in proportion with the same parameters of the control lots, which were not treated with liquid nitrogen. After triticale grains immersion in liquid nitrogen and than defrosted and taken for germination we registered a statistically non-significant inhibition in the growth in length of the vegetative organs (primary and adventitious roots, coleoptils and first leaves ) of the triticale plantlets.
第1页/共3235条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.