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Number of results: 236
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Abstract

The aim of the paper is the comparison of the least squares prediction presented by Heiskanen and Moritz (1967) in the classical handbook “Physical Geodesy” with the geostatistical method of simple kriging as well as in case of Gaussian random fields their equivalence to conditional expectation. The paper contains also short notes on the extension of simple kriging to ordinary kriging by dropping the assumption of known mean value of a random field as well as some necessary information on random fields, covariance function and semivariogram function. The semivariogram is emphasized in the paper, for two reasons. Firstly, the semivariogram describes broader class of phenomena, and for the second order stationary processes it is equivalent to the covariance function. Secondly, the analysis of different kinds of phenomena in terms of covariance is more common. Thus, it is worth introducing another function describing spatial continuity and variability. For the ease of presentation all the considerations were limited to the Euclidean space (thus, for limited areas) although with some extra effort they can be extended to manifolds like sphere, ellipsoid, etc.
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Authors and Affiliations

Marcin Ligas
Marek Kulczycki
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Abstract

In monitoring vertical displacements in elongated structures (e.g. bridges, dams) by means of precise geometric levelling a reference base usually consists of two subgroups located on both ends of a monitored structure. The bigger the separation of the subgroups, the greater is the magnitude of undetectable displacement of one subgroup with respect to the other. With a focus on a method of observation differences the question arises which of the two basic types of computation datum, i.e. the elastic and the fixed, both applicable in this method, is more suitable in such a specific base configuration. To support the analysis of this problem, general relationships between displacements computed in elastic datum and in fixed datum are provided. They are followed by auxiliary relationships derived on the basis of transformation formulae for different computational bases in elastic datum. Furthermore, indices of base separation are proposed which can be helpful in the design of monitoring networks. A test network with simulated mutual displacements of the base subgroups, is used to investigate behaviour of the network with the fixed and the elastic datum being applied. Also, practical guidelines are given concerning data processing procedures for such specific monitoring networks. For big separation of base subgroups a non-routine procedure is recommended, aimed at facilitating specialist interpretation of monitoring results.
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Authors and Affiliations

Witold Prószyński
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Abstract

In the paper a frequency method of filtering airborne laser data is presented. A number of algorithms developed to remove objects above a terrain (buildings, vegetation etc.) in order to obtain the terrain surface were presented in literature. Those all methods published are based on geometrical criteria, i.e. on a specific threshold of elevation differences between two neighbouring points or groups of points. In other words, topographical surface is described in a spatial domain. The proposed algorithm operates on topographical surface described in a frequency domain. Two major tools, i.e. Fast Fourier Transform (FFT) and digital filters are used. The principal assumption is based on the idea that low frequencies are responsible for a terrain surface, while high frequencies are connected to objects above the terrain. The general guidelines of this method were for the first time presented at (Marmol and Jachimski, 2004). Due to the fact that the preliminary results showed some limitations, two-stage filtering algorithm has been introduced. The frequency filter was modified in such a manner that different filter parameters are used to detect buildings than those to recognize vegetation. In the first stage of data processing the filtering concerning elimination of points connected with urban areas was applied. The low-pass filter with parameters determined for urban area was used for the whole tested terrain in that stage. The purpose of the second stage was to eliminate vegetation by using the filter for forest areas. The presented method was tested by using data sets obtained in the ISPRS test on extracting DTM from point clouds. The results of using the two-stage algorithm were com- pared with both reference data and with filtering results of eight method reported to ISPRS test. A numerical comparison of the filter output with a reference data set shows that the filter generates DTM of a satisfactory quality. The accuracy of DTM produced by the frequency algorithm fits the average accuracy of eight methods reported in the ISPRS test.
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Urszula Marmol
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Abstract

The paper presents the least admissible dimensions of black lines of spatial object images, according to Saliszczew, adjusted to the needs of database generalization. It is pointed out, that the adjusted dimensions are in agreement with the cartographic norm included in the National Map Accuracy Standards , and their application to the generalization 1 will allow, for any map scale, the determination of the: • value of the scale-dependent parameter of the generalization process, without user action; • measure of recognizability of the shortest black line section on the map, what helps to obtain unique results of line generalization; • measure of recognizability of black lines in the image – using a standard (elementary triangle) – helpful in obtaining unique result of line simplification, and an assessment of the process; • recognizability distance between lines of close buildings, securing unique aggregation of them; • verification of spatial object image lines visualization. The new solutions were tested with the Douglas-Peucker (1973) generalization algorithm, modified by the author, which treats the minimal dimensions as geometric attributes, while object classes and their data hierarchy as descriptive attributes. This approach secures uniqueness of results on any level of generalization process, in which data of spatial objects in the DLM model are transformed to conform with the requirements for the DCM model data.
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Tadeusz Chrobak
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Abstract

The paper presents the operation of two neuro-fuzzy systems of an adaptive type, intended for solving problems of the approximation of multi-variable functions in the domain of real numbers. Neuro-fuzzy systems being a combination of the methodology of artificial neural networks and fuzzy sets operate on the basis of a set of fuzzy rules “if-then”, generated by means of the self-organization of data grouping and the estimation of relations between fuzzy experiment results. The article includes a description of neuro-fuzzy systems by Takaga-Sugeno-Kang (TSK) and Wang-Mendel (WM), and in order to complement the problem in question, a hierarchical structural self-organizing method of teaching a fuzzy network. A multi-layer structure of the systems is a structure analogous to the structure of “classic” neural networks. In its final part the article presents selected areas of application of neuro-fuzzy systems in the field of geodesy and surveying engineering. Numerical examples showing how the systems work concerned: the approximation of functions of several variables to be used as algorithms in the Geographic Information Systems (the approximation of a terrain model), the transformation of coordinates, and the prediction of a time series. The accuracy characteristics of the results obtained have been taken into consideration.
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Maria Mrówczyńska
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Abstract

Movement is one of the most spectacular phenomena involving glaciers. Deter- mining glacier surface velocity is now a routine aspect of glaciological studies. These are geodetic methods, especially satellite positioning, that most frequently is applied in such work. Using the Hans Glacier (SW Spitsbergen) as an example, the presented paper is an attempt at defining the time resolution limit of changes in the velocity determined using GPS positioning technology. A test network was established in the area of the examined glacier in order to define the size and variability of the main satellite positioning biases as well as to define their impact on determining position and the calculated velocity. A discussion relating to achieved accuracy (differentiated from measurement precision) for baselines of a length of several kilometres in the high latitudes has also been presented.
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Marcin Rajner
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Abstract

The sequential method of integrating navigational parameters obtained from non-simultaneous navigational measurements is presented. The proposed algorithm of position coordinates estimation is general and includes two modes of data processing – from simultaneous and non-simultaneous measurements. It can be used in hybrid receivers of radionavigation systems integrating non-homogeneous position lines or in integrated navigation systems, particularly in receivers combining the measurements of various satellite navigation systems.
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Andrzej Banachowicz
Adam Wolski
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Abstract

A method of the improvement of the total station observations 3D adjustment by using precise geoid model is presented. The novel concept of using the plumb line direction obtained from the precise geoid model in combined GPS/total station data adjustment is applied. It is concluded that results of the adjustment can be improved if data on plumb line direction is used. Theoretical background shown in the paper was proved with an experiment based on the total station and GPS measurements referred to GRS80 geocentric reference system and with the use of GUGIK2001 geoid model for Poland.
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Authors and Affiliations

Edward Osada
Kateryna Sergieieva
Viktor Lishchuk
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Abstract

Resistance genes in response to root-knot nematode (Meloidogyne javanica) infection suppress one or more of several critical steps in nematode parasitism and their reproduction rate. The reaction of seven commercial tomato genotypes to M. javanica infection was investigated under greenhouse conditions. Current results classified these genotypes as: three resistant (Jampakt, Malika and Nema Guard), one moderately resistant (Fayrouz), and three susceptible (Castle Rock, Super Marmande and Super Strain B). Except Nema Guard, nematode infection significantly reduced plant height, fresh and dry weights of shoots of the other tomato genotypes. Leaf area was significantly reduced for all examined tomato genotypes except Malika and Nema Guard. Total chlorophyll was reduced in all tested tomato genotypes except Jampakt. Infection parameters of M. javanica and their population were significantly reduced on all nematode-resistant tomato genotypes compared to the susceptible genotypes. Also, the maturation rate of M. javanica was suppressed in the resistant genotypes compared to the susceptible genotypes. These results were confirmed by histological study that illustrated a delay in nematode development and their maturation. Total phenolic content significantly increased in nematode infected roots of both resistant and susceptible genotypes except Malika. Among non-infected roots, Malika showed the highest level of total phenols while after M. javanica infection, Nema Guard revealed the highest level of total phenols. Among infected roots, the highest level of total phenols was recorded in Castle Rock. These results suggested that using nematode-resistant tomato genotypes could provide an efficient and nonpolluting method to control root-knot nematodes.

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Authors and Affiliations

Mohamed Youssef Banora
Omar Abd Alhakim Almaghrabi
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Abstract

Cereal cyst nematodes (Heterodera spp.) are distributed globally and cause severe production losses of small grain cereals. To investigate the occurrence of cereal cyst nematodes in wheat-growing areas of Algeria, a survey was conducted and 27 cereal cyst nematode populations were collected. The populations were initially identified based on their morphological and morphometric characters, followed by molecular methods using speciesspecific primers, complemented by ITS-rDNA sequences. The morphological and morphometric features of second-stage juveniles (J2s) and cysts supported the presence of three Heterodera species: H. avenae, H. filipjevi and H. hordecalis. All morphological values of these distinct populations were very similar to those previously described for these species. Using species-specific primers for H. avenae and H. filipjevi, the specific bands of 109 bp and 646 bp confirmed the morphological identification of both species, respectively. In addition, the internal transcribed spacer (ITS) regions were sequenced to study the diversity of the 27 populations. These sequences were compared with those of Heterodera species available in the GenBank database (www.ncbi.nlm.nih.gov) and re-confirmed the identity of the species. Nineteen sequences of ITS-rDNA were similar (99–100%) to the sequences of H. avenae published in the GenBank, six sequences were similar (99–100%) to H. hordecalis, and two were similar (98–99%) to H. filipjevi. The results of this study are of great value to breeding programs and extension services, where they will contribute to the design of control measures to keep damaging nematodes in check.

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Authors and Affiliations

Djamel Smaha
Fouad Mokrini
Mustafa İmren
Aissa Mokabli
Abdelfattah A. Dababat
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Abstract

There are few reports in literature about the selectivity of postemergence application of herbicides for the control of eudicotyledon weeds (broadleaf) in chickpea. For this reason, the aim of this study was to investigate the selectivity of diphenyl-ether herbicides in chickpea influenced by the herbicides and application rates. A field experiment was conducted from February to June 2017 in Urutaí, state of Goiás, Brazil. Cultivar BRS Aleppo was used in the experiment. The experiment was set up in a randomized block design with 2 × 3 + 1 factorial arrangement and three replications. The first factor was herbicides (fomesafen and lactofen) with the second factor being herbicide rate (50, 75, and 100% of referenced rate) plus an untreated check as a comparison. The applied rates of herbicides were 250 and 180 g ⋅ ha–1 of fomesafen and lactofen, respectively. The selectivity of herbicides was evaluated according to agronomic characteristics (plant population, height, dry matter, number of pods per plant and 100-grain weight) and yields. Both herbicides, regardless of dosage, were selective in chickpea cultivation, even exhibiting leaf necrosis symptoms with visible injuries below 20% with no effect on yield.

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Authors and Affiliations

Luís Gustavo Barroso Silva
Lucas da Silva Araújo
Daniel José Gonçalves
Mateus Souza Valente
Anderson Rodrigo da Silva
Warley Marcos Nascimento
Paulo César Ribeiro da Cunha
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Abstract

In the present study, the effects of 10, 20, 30 ppm hormone mixtures (indole-3-acetic acid + gibberellic acid + kinetin) with 0.1, 0.3, 0.5 and 1 ppm zinc (Zn) concentrations alone and their mixtures on the cambial activity of sour cherry (Cerasus vulgaris Miller) cuttings were investigated. Morphological and anatomical developments of the plants were observed. The leaves of the plants treated with zinc were found to be greener than the control. Plants treated with zinc faded earlier than the control. The cambial zone thickness, the cambial zone cell line, the radial and tangential lengths of the cambial zone cells decreased with increasing concentrations of zinc and increased with increasing concentrations of hormones. The radial and tangential wall widths of the cambial zone cells increased with increasing zinc concentrations and decreased with increasing hormone concentrations. As a result, in the 0.1, 0.3, 0.5 and 1 ppm Zn concentrations, the cambial zone thickness decreased by 10, 28, 50 and 65%, respectively, compared to the control. Thirty ppm hormone mixture – H.M. (indole-3-acetic acid + gibberellic acid + kinetin) increased the cambial zone thickness by 65, 15, 5% in 0.1, 0.3 and 0.5 Zn, respectively, compared to the control. It was found that plant hormones importantly improved the harmful effects of zinc on the cambial activity of the plant cuttings.

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Authors and Affiliations

Kemal Yuce
Bekir Tileklioglu
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Abstract

Globally more than 5.2 billion hectares of farming fields are damaged through erosion, salinity and soil deterioration. Many salt stress tolerant bacteria have plant growth promoting (PGP) characteristics that can be used to overcome environmental stresses. Isolation and screening of salt-tolerant endophytes from Salicornia brachiata were achieved through surface sterilization of leaves followed by cultivation on 4% NaCl amended media. Performance of isolates towards indole-3-acetic acid (IAA) production, phosphate solubilization, ACC deaminase activity, ammonia production, siderophore production and stress tolerance were determined. On the basis of the highest plant growth promoting activity, SbCT4 and SbCT7 isolates were tested for plant growth promotion with wheat and maize crops. In the present study, a total of 12 morphologically distinct salt-tolerant endophytic bacteria was cultured. Out of 12 isolates, 42% of salt-tolerant endophytes showed phosphate solubilization, 67% IAA production, 33% ACC-deaminase activity, 92% siderophore production, 41.6% ammonia production and 66% HCN production. A dendrogram, generated on the basis of stress tolerance, showed two clusters, each including five isolates. The bacterial isolates SbCT4 and SbCT7 showed the highest stress tolerance, and stood separately as an independent branch. Bacterial isolates increased wheat shoot and root dry weights by 60–82% and 50–100%, respectively. Similarly, improved results were obtained with maize shoot (27–150%) and root (80–126%) dry weights. For the first time from this plant the bacterial isolates were identified as Paenibacillus polymyxa SbCT4 and Bacillus subtilis SbCT7 based on phenotypic features and 16S rRNA gene sequencing. Paenibacillus polymyxa SbCT4 and B. subtilis SbCT7 significantly improved plant growth compared to non-inoculated trials.

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Authors and Affiliations

Arun Karnwal
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Abstract

Rice blast is one of the most destructive rice diseases known to cause considerable yield losses globally. Plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) are closely associated with rice plants and improve plant growth and health. To determine how isolated bacteria trigger rice growth, an assessment of phosphate solubilization and auxin production mechanisms was carried out in vitro and in vivo. In this study, the interactions between PGPR and Rhizophagus irregularis were evaluated in wildtype and CYCLOPS mutant plants to provide a sustainable solution against blast disease and reduce the amount of yield loss. Importantly, Bacillus subtilis UTSP40 and Pseudomonas fluorescens UTSP50 exhibited a suppressive effect on AMF colonization which shows the probable existence of a functional competition between AMF and PGPR to dominate the rhizosphere. On the other hand, R. irregularis decreased the biocontrol activity of B. subtilis UTSP40 in wild type, although this reduction was not significant in mutant plants. Results showed that the same defense-related genes were induced in the roots of wild type colonized by B. subtilis UTSP40 and R. irregularis. Therefore, plant cell programs may be shared during root colonization by these two groups of beneficial microorganisms.

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Authors and Affiliations

Samira Peighami Ashnaei
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Abstract

Interest in growing roses in Poland is related to the production of cut flowers as ornamentals and of petals and hips for cosmetics or food products. However, recently there has been an increasing number of reports of pest damage on rose plantations. In the case of fruits the damage has been attributed to flies (Rhagoletis alternata) or moths (Cydia tenebrosana), while nematodes have been implicated for growth reduction even on plantations grown under soil-less conditions. Field trials and laboratory experiments to test the possibility of controlling R. alternata larvae or pupae with entomopathogenic fungi and nematodes resulted in a lack of parasitism. On the other hand, the use of Bacillus thuringiensis subsp. kurstaki or Cydia pomonella granulovirus effectively controlled C. tenebrosana. Meloidogyne incognita infestation of roses growing on rock wool substrate was drastically reduced by Arthrobothrys oligospora or abamectin. Factors such as the method of product application or pest susceptibility to the used microbial-based products accounted for the observed differences in efficacy.

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Authors and Affiliations

Eligio Malusá
Malgorzata Tartanus
Grażyna Soika
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Abstract

The aim of this work was to evaluate the use of the naphthalic anhydride safener on the protection of common bean cultivars BRS-Estilo (carioca) and BRS-Esplendor (black) from negative effects of herbicides. Two experiments were conducted, one for each cultivar in a complete randomized design with five replications, in a 6 × 3 factorial scheme, with six herbicide treatments: bentazon, fluazifop-P + fomesafen, bentazon + imazamox, fomesafen, cloransulam, and control without application, and three naphthalic anhydride treatments: without application, foliar application, and application via seed treatment. Visible injuries at 7, 14 and 21 days after application, photosystem II electron transport rate, and plant dry weight were evaluated. The naphthalic anhydride applied via foliar, and seed treatment reduced significantly the visible injuries in relation to the control when using the herbicides bentazon, fluazifop-P + fomesafen, bentazon + imazamox, and cloransulam. The photosystem II electron transport rate was protected by anhydride applied via foliar and seed treatment when using the herbicides bentazon, fluazifop-P + fomesafen and bentazon + + imazamox. The application of naphthalic anhydride via seed treatment protected the BRS-Estilo and BRS-Esplendor common bean cultivars, with no reductions in the plant dry weight when using the herbicides fluazifop-P + fomesafen, and fomesafen. The use of naphthalic anhydride via seed treatment and foliar application protected BRS-Estilo and BRSEsplendor common bean cultivars, from the negative effects of fluazifop-P + fomesafen and fomesafen herbicides. Thus, this practice has potential to be used in common beans.

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Authors and Affiliations

Fábio Henrique Krenchinski
Edicarlos Batista de Castro
Victor José Salomão Cesco
Diego Belapart
Danilo Morilha Rodrigues
Caio Antonio Carbonari
Edivaldo Domingues Velini
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Abstract

Two field experiments were established at the Agricultural Experimental Station of the National Research Centre at Nubaria, Beheira Governorate, Egypt to study the herbicidal potential of the leaf extract of Eucalyptus citriodora at 5, 10, 15, 20 and 25% compared to two hand hoeing, unweeded treatments and the chemical herbicides Bentazon + Clethodium, Bentazon + Fluazifop-P-butyl and Butralin on pea plants and associated weeds. The results indicated that two hand hoeing achieved the maximum weed depression as expressed by the dry matter of total weeds. The dry matter of total weeds decreased by 95.08 to 94.77% as compared with unweeded treatment 50 and 70 days after sowing (DAS) followed by Butraline (93.93–94.65%), Bentazon + Clethodium (93.26–94.07%), Bentazon + Fluazifop--P-butyl (91.82–92.77%) and leaf extract of Eucalyptus at 25% (91.61–91.95%). Furthermore, the reduction in weed development was accompanied by enhanced pea growth and yield. The results revealed that two hand hoeing was the best treatment to increase plant height, shoot dry weight and SPAD value at 50 and 70 DAS. Also, two hand hoeing produced the maximum values of pod length and number of seeds/pod. The results also indicated that Bentazon + Clethodium treatment gave observable values [recorded 72.96% in pod yield (ton ⋅ fed.–1) over that of unweeded control] of number of pod/plant, weight of pod/plant, seed yield/fed and protein percentage. Also, the results revealed great increases in the growth of pea as well as yield due to treatment with E. citriodora dry leaf extract at 25%. [recorded 64.8% in in pod yield (ton ⋅ fed.–1) over that of unweeded control]. So, the results indicated using Bentazon + Clethodium as well as E. citriodora dry leaf extract at 25% to control weeds associated with pea plants. The authors suggested application of E. citriodora dry leaf extract at 25% in controlling weeds associated with pea plants as a safe method that avoids environmental contamination.

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Authors and Affiliations

Ibrahim Mohamed El-Metwally
Kowthar Gad El-Rokiek
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Abstract

Pest mites of the family Tetranychidae are commonly reported in several legumes. However, reports of their occurrence in lima beans are insipient, especially in Brazil. The objective of this research was to record the occurrence of mites in lima bean plants and to describe their damage in this Fabaceae. Tetranychus neocaledonicus André and Mononychellus planki McGregor were found in lima bean plants, Phaseolus lunatus (Fabaceae or Leguminosae). The lima bean plants, when infested by these mites, initially exhibit small whitish spots in the leaflets, which with increasing population density rapidly evolve into chlorotic patches, followed by silvering, and may dry out and fall due to their overfeeding. The extent of the damage caused to lima bean plants and the adaptability of the mite to warm and dry conditions indicate that T. neocaledonicus has greater potential as a lima bean pest than M. planki in northeastern Brazil. This is the first record of these mites associated with P. lunatus.

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Authors and Affiliations

Antonio Vieira Gomes Neto
Paulo Roberto Ramalho Silva
Jayara Dayany Costa Silva
Mayara Fernandes dos Santos
José Wagner da Silva Melo
Solange Maria de França
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Abstract

The insecticidal efficiency of Ag-loaded 4A-zeolite (ZAg) and its formulations with Rosmarinus officinalis essential oil (RO) was evaluated against Sitophilus oryzae (L.) and Rhyzopertha dominica (F.). For comparison, different rates of ZAg (0.25, 0.5, 0.75, and 1 g ⋅ kg–1 wheat) were used solely and in a combination with LC50 concentrations of RO. Mortality was assessed after 7, 14, and 21 days of insect exposure to treated wheat. The progeny production was also evaluated. The use of ZAg accomplished a complete mortality (100%) on S. oryzae and 96.67% on R. dominica as well as 100% mortality of progeny against the two insect species after the longest exposing duration (21 days), at the highest rate (1 g ⋅ kg–1). On the other hand, the complete mortalities of ZAg formulations on S. oryzae were obtained after 14 d of treatment with F1 formulation (0.605 g ⋅ kg–1 RO + 0.25 g ⋅ kg–1 ZAg) and after 7 days with the other tested formulations. In addition, the complete mortality on R. dominica was obtained only by F8 (0.059 g ⋅ kg–1 RO + 1 g ⋅ kg–1 ZAg) formulation after 14 days of treatment. Concerning the efficiency of the examined formulations on the progeny of S. oryzae, F1 (0.605 g ⋅ kg–1 RO + 0.25 g ⋅ kg–1 ZAg) and F2 (0.605 g ⋅ kg–1 RO + 0.5 g ⋅ kg–1 ZAg) formulations recorded 100% mortality. In addition, F3 (0.605 g ⋅ kg–1 RO + 0.75 g ⋅ kg–1 ZAg) and F4 (0.605 g ⋅ kg–1 RO + 1 g ⋅ kg–1 ZAg) formulations suppressed the progeny production. Furthermore, the complete mortality of R. dominica progeny was obtained with F7 (0.059 g ⋅ kg–1 RO + 0.75 g ⋅ kg–1 ZAg) and F8 (0.059 g ⋅ kg–1 RO + 1 g ⋅ kg–1 ZAg) formulations. ZAg, especially its formulations with R. officinalis oil, had potential effects against two stored-product insects. F1 and F8 formulations could be treated efficiently on S. oryzae and R. dominica, respectively.

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Authors and Affiliations

Ahmed M. El-Bakry
Hanan F. Youssef
Nahed F. Abdel-Aziz
Elham A. Sammour
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Abstract

Tomato is an economically important vegetable crop which is attacked heavily by insect pests leading to reduction of yield and quality of the fruits. Field experiments were carried out to investigate the dissipation of methomyl (a common insecticide) used mainly on tomato fruits. LC-MS/MS coupled with the QuEChERS method were used for the determination of methomyl. The results showed that the recovery using matrix-matched standards ranged from 87.8 to 101.3%, with relative standard deviation of 2.5 to 7.5%. Kinetics equation, Log R = log R0 – 0.434 Kt, was used to calculate the rate of degradation in tomato, soil and water. Residue half-life calculated using kinetic rate ranged from 1.95 to 1.63 days in tomato and soil, respectively. From the results it was concluded that tomato fruits can be safely harvested for consumption after 15 days of application based on estimated preharvest interval (PHI). It is advisable to re-estimate the PHI regularly owing to data from the EU and Codex.

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Authors and Affiliations

Dalia El-Hefny
Ibrahim Abdallah
Rania Helmy
Hend Mahmoud
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Abstract

The current research aimed to use non traditional methods to control some stored grain insects. The effects of 180 millitesla (mT) magnetic field (MF) for six different exposure periods (3 min, 30 min, 1 h, 12 h, 24 h and 48 h) on mortality (%) of two stored grain insects, Tribolium casteneum adults and Trogoderma granarium larvae, reduction in F1-progeny (%), seeds germination (%) and seed components (%) after 8 months storage period were studied under laboratory conditions. According to results, the mortality (%) of tested insects increased with increasing of MF time exposure. Trogoderma granarium was more resistant than T. casteneum in which mortality reached 56 and 75%, respectively 14 days after from exposure period. Without any negative effect on seeds germination (%) the MF was very effective in protecting stored wheat from insect infestation up to 8 months compared to non-magnetic seeds which became infested after 3 months of storage. Furthermore, the germination (%) was accelerated by 6 h compared to non-magnetic seeds. The MF level caused a slight increase in the percent of total carbohydrate, crude protein and ash while slightly decrease the percent of moisture, total fats and crude fiber.

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Authors and Affiliations

Doaa Mohamed Zein
Abdelkhalek Hussein
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Abstract

Polyphenol oxidase partial gene PG-PPO was cloned and characterized from Pennisetum glaucum (pearl millet) which showed 42% identity to a PPO sequence isolated from wheat at the region of Copper B with a score of 40 and e-value of 2.8. Multiple sequence alignment results revealed similarity to polyphenol oxidase (PPO) sequences from wheat, trifolium, lettuce, apricot, tobacco, tomato, pokeweed, apple, grape and poplar especially at the Copper B region of PPO. The 395 bp pearl millet PPO sequence was AT rich (53.3%) and contained the highly conserved amino acids of histidine-rich copper binding sites similar to PPO sequences from other crops. Results also indicated that PPO in pearl millet exists in multi copy. The role of the isolated PPO gene during pearl millet-downy mildew interaction was analyzed and the results showed significantly higher and rapid accumulation of PPO mRNAs in resistant pearl millet seedlings inoculated with Sclerospora graminicola in comparison to the susceptible control, demonstrating that the PPO plays a prominent role in pearl millet defense against pathogens, particularly downy mildew pathogen.

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Authors and Affiliations

Sathyanarayana Niranjan-Raj
Senapathyhally Nagaraju Lavanya
Siddaiah Chandra Nayaka
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Abstract

Root associated bacteria were isolated from Suaeda nudiflora and two isolates were selected for this study: rhizospheric Bacillus megaterium and endophytic Pseudomonas aeruginosa. These isolates were inoculated into maize variety Narmada Moti during its germination. TTC (2, 3, 5-triphenyl tetrazolium chloride) staining was used to confirm the association of the isolates with the maize root. The effects of these root associated bacteria were tested alone and in combinations for cell wall reinforcement and the induction of defense enzymes such as phenylalanine ammonia lyase (PAL) and β-1,3-glucanase in the presence of fungal pathogen Aspergillus niger in maize. The results indicated that the rhizospheric bacteria had a greater fight response to fungal infection than the endophhytic bacteria due to cell wall lignification as well as the rapid induction of higher concentrations of defense related enzymes.

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Yachana Jha
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Abstract

Genetically modified Bt cotton (Gossypium hirsutum) leaves with typical symptoms of Alternaria early blight disease resembling that of tomato and potato were observed in the main cotton growing schemes in Sudan. Symptoms on leaves appeared as either brown 2leaf spot with gray centers or leaf blight with concentric rings. Pathogenicity tests using isolates with both symptoms showed that the isolated fungi were highly pathogenic to both G. hirsutum and G. barbadense cotton varieties. Alternaria alternata isolated from infected tomato and potato leaves with early blight symptoms was included for comparison. Microscopic examination showed that the mean length of conidia from cotton, tomato and potato isolates ranged from 26.25 to 45.45 μm, while the width ranged from 9.56 to 13.64 μm. The mean number of transverse septa among all isolates was 3.4 to 5.7 and the peak length ranged from 3.75 to 7.8 μm. Based on morphological characteristics the two isolates from cotton were identified as A. alternata. Genomic DNA was extracted directly from fungal cultures grown on potato dextrose agar (PDA) plates using a Zymo Research Quick DNA kit. A species-specific primer using the internal transcribed spacer ribosomal DNA (ITS rDNA) PCR scoring indicated the presence of A. alternata using primer pair ITS4/ITS5. Amplifications of the internal transcribed spacer region of 600 bp revealed 100% identity of the isolated fungus from cotton with A. alternata from tomato and potato. These data oblige us to reconsider the presence of A. alternata in the four main cotton growing schemes in Sudan while these symptoms have always been described for tomato and potato early blight disease.

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Authors and Affiliations

Omyma Elmahi Mohamed
Mayada Mamoun Beshir
Nafisa Elmahi Ahmed

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