Cytoembryological aspects of fertilisation of plum cultivar "Pozna plava" (Prunus domestica L.)

Kod sorte šljive Pozna plava, u trogodišnjem periodu, ispitivano je više citoembrioloških aspekata koji su vezani za dinamiku odvijanja procesa oplođenja, tokom prvih deset dana od momenta punog cvetanja. Fluorohromnim bojenjem analizirana je vitalnost semenih zametaka kao i kvantitativni parametri rasta polenovih cevčica, u tri varijante oprašivanja: slobodno oprašivanje, stranooprašivanje i samooprašivanje. U varijanti stranooprašivanja korišćen je polen sorti šljive Hanita, Čačanska najbolja i Presenta. Klijavost polena korišćenih oprašivača prethodno je utvrđena in vitro na agaro-saharoznoj podlozi, dok su morfološke osobine polena analizirane pomoću skenirajućeg elektronskog mikroskopa. U ispitivanim varijantama oprašivanja analizirano je inicijalno i finalno zametanje plodova. U dvogodišnjem periodu ispitivano je funkcionalno stanje embrionove kesice u prvih deset dana od momenta punog cvetanja u dve varijante: slobodno oprašivanje i bez oprašivanja (kontrola). U trogodišnjem periodu, u poljskim uslovima, ispitivan je uticaj temperature, na interakciju muškog gametofita i ženskog sporofita. U analiziranim morfološkim karakteristikama polena sorta šljive Pozna plava se razlikovala od ostalih sorti, gde je izuzev širine polenovog zrna, u svim ostalim analiziranim parametrima imala najveće vrednosti. Analiza kvantitativnih parametara rasta polenovih cevčica u stubiću tučka pokazala je najbolje vrednosti u varijanti stranooprašivanja, dok se u sve tri godine ispitivanja kao najslabila pokazala varijanta slobodnog oprašivanja. Prisustvo inkompatibilnih polenovih cevčica u gornjoj trećini stubića kao i pojava njihovog specifičnog rasta u plodniku u svim analiziranim varijantama oprašivanja bila je izražena u manjoj meri, tako da nije imala većeg uticaja na broj oplođenih semenih zametaka, a samim tim i na broj inicijalno i finalno zametnutih plodova. Analiza semenih zametaka u varijanti slobodnog oprašivanja pokazala je da oni u vreme punog cvetanja u najvećem broju sadrže embrionove kesice koje se nalaze u ranoj osmojedarnoj fazi. Takođe, i u varijanti bez oprašivanja je utvrđen ovaj stadijum u vreme punog cvetanja, koji je brzo prelazio u petojedarni stadijum.Over a three-year period, a study was conducted on the Pozna plava cultivar, focusing on a number of cyto-embryological aspects related to the dynamics of fertilisation process during the ten-day phase that follows the moment of full bloom. Fluorochrome dying was used to analyse the vitality of ovules and the quantitative growth parameters of the pollen tubes, thorough three pollination variants: open pollination, cross pollination, and self pollination. In the cross-pollination variant, pollen of the Hanita, Čačanska najbolja and Presenta cultivars was used. An agarosesucrose base was used for in vitro pre-determination of pollen germination of the used pollenisers, whereas the pollen morphological traits were analysed using the scanning electronic microscope. Initial and final fruit set was analysed in the examined pollination variants. In the two years of the study, functional condition of the embryo sac was examined within the first ten days following the moment of full bloom, comprising two variants: open pollination and no-pollination (as the control group). The impact made by temperature on the interaction between the male gametophyte and female sporophyte was examined during the three-year period of study. The analysis of the morphological characteristics of the pollen, the Pozna plava cultivar recorded different results compared to the other cultivars, reaching the highest values in all of the analysed parameters except the pollen grain width. The analysis of the quantitative growth parameters of the pollen tubes inside the style revealed the highest values in the self-pollination variant, whereas the lowest values of this parameter were recorded in the open pollination variant, in all the three years of the research. The presence of incompatible pollen tubes in the upper third of the style, as well as occurrence of their specific growth inside the ovary in all of the analysed pollination variants was less expressed and had no significant impact on the number of fertilised ovules, thus having no major impact on the number of initial and final fruit set. The analysis performed in the open pollination variant showed that in the full bloom most of the ovules contained embryo sacs in the early eight-nucleate phase..

Unusual behavior of growing pollen tubes in the ovary of plum culture (Prunus domestica L.)

Unusual behavior of growing pollen tubes in different combinations of pollination was observed in the ovary of the plum (Prunus domestica L.) cv 'Čačanska Lepotica'. It primarily refers to several issues, i.e. the curling up of pollen tubes within the micropyle, the growth of two pollen tubes into the nucellus of an ovule, the occurrence of a bundle above the nucellar cap and fluorescence of the part of the embryo sac containing the egg apparatus. Upon the growth of pollen tubes into the nucellus of the ovule, subsequently penetrating pollen tubes form a bundle either above the micropyle entrance or above the nucellus. Branching and bending of pollen tubes by 180o upon their growth into the micropyle was also observed

Contribution to the investigation of the influence of tire non-uniformity on the lateral tire characteristics

Tire models are widely used in research in the field of vehicle dynamics and noise, and especially in the simulation of their movement under the action of forces and moments. In general case, we distinguish theoretical models defined on the basis of tire construction and empirical or semi-empirical models based on experimental tests. In addition, a combination of these two types of models can also produce tire models. In practice, there is a very wide range of mathematical tire models defined using finite element analysis, by approximation of polynomials of different degrees, by approximation of magic formula, etc. In this paper, an attempt is made to calculate non-stationary lateral characteristics of tires on the basis of experimental stationary lateral characteristics, using two-parameter higher level polynomials. This polynomials define the tire lateral characteristics, and take into account their non-uniformity. More specifically, the lateral characteristics are approximated as a function of the dynamic change of the slip angle, radial load due to tire non-uniformity and time

Properties of some Late Season Plum Hybrids from Fruit Research Institute Čačak

Since 1979 to 2012 fifteen plum cultivars were named and released in Fruit Research Institute, Čačak. Some of these cultivars, such as Čačanska Lepotica, Čačanska Rodna and Čačanska Najbolja are grown in most important plum growing countries in Europe. Also, these cultivars are used as parent cultivars in many plum breeding programs. In addition to the cultivars, large number of promising hybrids are created in Fruit Research Institute, Čačak and some of them, in this moment, are candidates for new cultivars. Therefore, in 2014 and 2015, we investigated the most important properties of four promising late season hybrids and standard cultivar ‘Stanley’. All four hybrids were harvested since beginning of September (34/41/87) until the beginning of the third decade of September (10/23/87). The earliest flowering time was recorded in hybrid 34/41/87 and the latest in standard cultivar ‘Stanley’. Hybrids 10/23/87 and 26/54/87 generally had the highest fruit weight and all three fruit dimensions. Also these hybrids had the highest content of total sugars and sucrose and highest pH value, but poorest total acids content. The highest content of invert sugars and total acids was recorded in hybrid 22/17/87. This hybrid also, had the highest yield per tree and per hectare while the hybrid 34/41/87 had the lowest these values. Standard cultivar ‘Stanley’ had the largest stone weight and the highest amount of soluble solids

Toxic-Metal-Induced Alteration in miRNA Expression Profile as a Proposed Mechanism for Disease Development

Toxic metals are extensively found in the environment, households, and workplaces and contaminate food and drinking water. The crosstalk between environmental exposure to toxic metals and human diseases has been frequently described. The toxic mechanism of action was classically viewed as the ability to dysregulate the redox status, production of inflammatory mediators and alteration of mitochondrial function. Recently, growing evidence showed that heavy metals might exert their toxicity through microRNAs (miRNA)-short, single-stranded, noncoding molecules that function as positive/negative regulators of gene expression. Aberrant alteration of the endogenous miRNA has been directly implicated in various pathophysiological conditions and signaling pathways, consequently leading to different types of cancer and human diseases. Additionally, the gene-regulatory capacity of miRNAs is particularly valuable in the brain-a complex organ with neurons demonstrating a significant ability to adapt following environmental stimuli. Accordingly, dysregulated miRNAs identified in patients suffering from neurological diseases might serve as biomarkers for the earlier diagnosis and monitoring of disease progression. This review will greatly emphasize the effect of the toxic metals on human miRNA activities and how this contributes to progression of diseases such as cancer and neurodegenerative disorders (NDDs)

DOI:10.2298/ABS1001137D UNUSUAL BEHAVIOR OF GROWING POLLEN TUBES IN THE OVARY OF PLUM CULTURE (PRUNUS DOMESTICA L.)

Abstract – Unusual behavior of growing pollen tubes in different combinations of pollination was observed in the ovary of the plum (Prunus domestica L.) cv ‘Čačanska Lepotica’. It primarily refers to several issues, i.e. the curling up of pollen tubes within the micropyle, the growth of two pollen tubes into the nucellus of an ovule, the occurrence of a bundle above the nucellar cap and fluorescence of the part of the embryo sac containing the egg apparatus. Upon the growth of pollen tubes into the nucellus of the ovule, subsequently penetrating pollen tubes form a bundle either above the micropyle entrance or above the nucellus. Branching and bending of pollen tubes by 180º upon their growth into the micropyle was also observed. Key words: Plum, ovary, pollen tube growth, fluorescent microscop

Cover crop effects on the fate of N in sweet maize (Zea mays L. saccharata Sturt.) production in a semiarid region

This research aimed to determine the effects of different cover crops and application of bio-fertilizer on dynamic of nitrogen in the soil and sweet maize yield. Also, we evaluated the effect of fall-winter species (common vetch, field pea, winter oats, fodder kale) and a mixture of vetch and field pea with oats used as cover crops, as such as dead organic mulch and traditional variant, without coverage on biomass, chlorophyll and protein content in leaves and grain of main crop. Biomass production and N uptake by cover crops ranged from 4.25 to 90.20 kg ha(-1) and from 0.34 to 133.80 kg ha(-1) N, respectively, depending on cover crop type. At harvest soil nitrate content in treatments with cover crops was 50-90% lower than in the control, reducing spring N leaching risk. Residual mineral N significantly increased with application of microbiological fertilizer. The chlorophyll content of the main crop was significantly lower in treatments without cover crops. Consequently, sweet maize yield was the highest in fodder kale and field pea (7263.83 and 7177.27 kg ha(-1)) treatments, but the smallest in winter oat and common vetch (6802.47 and 6184.14 kg ha(-1)). In terms of all investigated traits, particularly grain yield, cover crops and microbiological fertilizer expressed more efficiency in the dry year. It could be concluded that N content should be controlled effectively by sowing main crops after planting of cover crops in biological farming systems in a semiarid region

Clinical significance of proliferation index and e-cadherin expression in colorectal adenocarcinoma

Introduction/Objective The aim of this study is to examine the association of E-cadherin expression and high proliferation index (proIDX) with clinical and pathological indicators of colorectal cancer progression. Methods The biopsy of 72 patients, obtained by resection of colorectal cancer, was routinely processed at the Institute of Pathology of the Clinical Centre of Montenegro, embedded in paraffin and archived. Based on the archived pathohistological reports, two study groups were formed: the first group (n = 72) consisted of operative biopsies of colorectal cancer, and the control group (n = 72) consisted of biopsies of adja-cent non-tumor tissue. Routine hematoxylin-eosin and immunohistochemical avidin-biotin-peroxidase complex method with anti-Ki67 and anti-E-cadherin antibodies was applied on. After quantification of the results for statistical tests, the software package SPSS for Windows (19.0) was used. Results In colorectal carcinoma, we observed a significant association of proIDX with pT stage, lymph and blood vessel invasion, perineural invasion, lymph node metastases and distant metastases, and Astler–Coller stage tumor disease. We also observed that the absence of E-cadherin was significantly associated with pT stage, lymph and blood vessel invasion, perineural invasion with lymph node metas-tases, distant metastases, with C2 and D Astler–Coller tumor stage. E-cadherin expression is associated with proIDX with a significantly high, negative correlation coefficient. Conclusion Our results indicate that it is possible to differentiate patients into groups with a higher or lower risk of developing metastatic disease, based on the expression of Ki67 and E-cadherin

Effect of annealing on luminescence of Eu3+- and Sm3+-doped Mg2TiO4 nanoparticles

This work explores the influence of annealing temperature on the structure and luminescence of 2 at% Eu3+ and 1 at Sm3+-doped Mg2TiO4 nanopowders produced via Pechini-type polymerized complex route. Mg2TiO4 samples were annealed at 7 different temperatures (400 degrees C, 450 degrees C, 500 degrees C, 550 degrees C, 600 degrees C, 650 degrees C and 700 degrees C) to determine the temperature range in which cubic inverse spinel structure is stable and to follow the changes of material luminescence properties. X-ray diffraction revealed that crystallization of both Eu3+ and Sm3+-doped Mg2TiO4 nanopowders starts at 400 degrees C, and that Sm3+ doped Mg2TiO4 starts to decompose at 650 degrees C, while Eu3+ doped Mg2TiO4 starts to decompose at 700 degrees C. Samples annealed at higher temperatures show higher crystallinity and larger crystallite size. Mg2TiO4 powder annealed at 600 degrees C is composed of similar to 5 nm size nanoparticles agglomerated in micron-size and dense chunks. The emission spectra of nanoparticles are composed of emissions from defects in Mg2TiO4 host and characteristic emissions of Eu3+ (D-5(0) - GT F-7(J)) and Sm3+ ((4)G(5/2) - GT H-6(J)) ions. The stronger emission and longer emission decays are observed with samples annealed at high temperatures. In the case of the Eu3+ ions emission intensity increased one order of magnitude between samples annealed at 400 degrees C and 650 degrees C. (C) 2015 Elsevier B.V. All rights reserved

Environmental conditions and crop density as the limiting factors of forage maize production

In rain-fed cropping, defining the best combination of practices could achieve high forage yield and silage quality. The aim of this study was to compare energetic quality of produced silage with productive characteristics of forage maize cultivated on alluvium and hydromorphous black soil in rain-fed conditions at four plant densities (68-74,000 plants ha-1) during the period 2005- 2010. Yield and energy parameters were increased to some extent at higher crop densities indicating that higher densities (74,000 plants ha-1) were potentially better for high forage and DM yields, while lower densities (70,000 plants ha-1) were better for the increase of energy parameters of produced silage. [Projekat Ministarstva nauke Republike Srbije, br. TR-31037