النشر العلمي

  • Water harvesting model for improved rangeland productivity in Butana, Sudan

The above-ground biomass and floristic composition of Butana rangelands in Sudan were assessed in 2006 with field surveys covering 25 sites. The remote sensing data derived from Spot image for the same period was integrated to the field surveys to map the spatial distribution of biomass production (kg ha-1) using the perpendicular vegetation index. A rainfall map of the region was established from the meteorological data of the season and the digital elevation model. The rain use efficiency factor, which is the quotient of the annual primary production (kg dry matter ha-1) of a season by rainfall (mm) of the same season, was used as a rangeland degradation and desertification indicator in Butana. To test the potential of water harvesting techniques on biomass production, two seasons’ experiments were conducted (2006 and 2007). Their results were used to simulate the potential of biomass production with water harvesting application through a general model that linked remote sensing output, field measurement and water harvesting results.

published in Revue d’élevage et de médecine vétérinaire des pays tropicaux

  • Resistance against Glyphosate and 2-4-D in the Indigenous Strain of A. Tumefaciens “SDB0012” And Its’ Association with Oxidase Inhibition

ewline"> This study was conducted at University of Gezira, Sudan; The National Institute for Promotion of Horticultural Exports and Faculty
of Engineering and Technology in 2008-09. It aimed at examining resistance of the indigenous strain of A. tumefaciens “SDB0012”
to application of herbicides and role of oxidase in such resistance. Pendimethalin, Glyphosate and 2-4-D were used at dilution rates
of 1:200 and 1:1 of herbicide: distilled water. Only Glyphosate and 2-4-D were further investigated at dilution rates of 2:1 and 3:1.
Cyanide was used as an oxidase inhibitor at dilution rates of 0.02, 0.2, 0.5 and 2.0 mg/l. It was used to inhibit oxidase activity in the
bacterial suspension and on potato discs treated with the bacterium only and with herbicides. Results concluded that the bacterium
“SDB0012” was sensitive to Pendimethalin at low concentrations of 1:200 and 1:1. Further investigations concluded that the
bacterium resisted Glyphosate better than 2-4-D at dilution rates of 2:1 and 3:1 and that resistance to both herbicides was highly
stable. Results also indicated that resistance to Glyphosate and 2-4-D was not associated and independent. Resistance to both
herbicides was found positively affected by time of incubation. Results also showed that the intensity of purple color, as an indicator
for oxidase, reduced as the concentration of cyanide increased from 0.02 to 2.0 mg/l. This result indicated that oxidase had no effect
on resistance of the bacterium against Glyphosate and 2-4-D. Therefore, it was suggested that this resistance might be due to effects
of other independent gene(s).

published in International Journal of Science and Technology Volume 5 No. 1,

  • DNA barcoding and mini-barcoding as molecular tools for identification of fruit flies (Diptera: Tephritidae)

line"> <The objectives of this study were to assess the proportions of correct identifications (ID) in
tested genera and to elucidate the efficacy of three fragments (min-barcode) of COI barcode region
in providing comparable information. The DNA barcoding in three tephritid genera was tested by
considering 493 DNA barcodes involving 86 species belonging to the genera Bactrocera (33
species), Ceratitis (21 species) and Dacus (32 species). Barcoding simulations were performed by
using a reference dataset of 15,948 insect DNA barcodes. It was performed under a “best case
scenario” viz. by providing one or more potential con-specific matches in the reference dataset for
each query. Results showed that the Best Match (BM) criterion (i.e. the criterion currently adopted
by BOLD) yielded different proportions of correctly identified taxa in Bactrocera (BM=0.839),
Ceratitis (BM=0.868) and Dacus (BM=0.962). The proportions of correctly identified queries by
using three mini-barcode fragments (MB1, MB2, MB3) of 220bp (corresponding to the first, second
and last third of the COI barcode region) ranged from 0.71 ± 0.17 in MB1 to 0.83 ± 0.10 in MB2.
Currently, however, the application of DNA barcoding in tephritid species is limited by the low
number of barcoded taxa in the reference databases. This situation increases the probability of
making Type II errors (i.e. incorrect ID for queries without conspecifics in the reference database).
On the other hand, the probability of making Type I errors (incorrect ID for queries with
conspecifics in the database) is relatively limited (4-16% in our simulations). These considerations
suggest that DNA barcoding may not be a fool proof method for the molecular ID of tephritid fruit
flies. Still, DNA barcoding could be effective under well-defined conditions, where only a limited
number of well-known tephritid taxa, with well characterized intraspecific variation, are to be
distinguished.

published in Arab Journal of iotechnology

  • Characterization of Powdery Mildew of Snake Melon (Cucumis melo var. Flexuosus L.) And Evaluation of Some Inbred Lines of Snake Melon for Powdery Mildew Resistance

ewline"> ABSTRACT
Snake melon (Cucumis melovar. flexuosus L.) is among the desirable melon groups in the Sudan, it is consumed locally as green
salad or pickles. The crop is being affected by major biotic and abiotic stresses which have laid to drastic reduction in yield. One of
the major biotic stress is powdery mildew. The disease can reduce yield by decreasing fruit size, number of fruits. Cucurbit powdery
mildew is most frequently caused by two obligate fungal pathogens, Podosphaera xanthii and Golovinomyces cichoracearum. The
most commonly identified pathogen; particularly in warmer production regions has been P. xanthii, therefore the study was carried
out to identify the causal agent of the disease, to screen some inbred lines of snake melon (Cucumis melo var. flexuosus) for
resistance to powdery mildew and to determine the physiological races under local field. Nine landraces of snake melon were used,
they were sampled for incidence and severity of the disease under studied area. Disease incidence was determined by using rate and
severity of the disease by using severity scale of 1- 5. A Complete Randomized Block Design (CRBD), with three replications was
used. Although determination of the physiological races by the used differential melon cultivars growing in the field was carried out.
Pathogen identification was done microscopy according to morphological characters of conidia, conidiophores, conidia germination,
presence or absence of fibrosin bodies and the perfect stage (chasmothecia) of the fungus. Field trial revealed that, incidence ranged
from (50.0–80.0%) on leaves. The severity was (2.0–4.8) moderate–very severe infection (40.0–96.0%) on leaves. Significant
differences (P= 0.05) were observed in disease severity. The causal agent of powdery mildew disease of snake melon (Cucumis melo
var. flexuosus) was conclusively identified as Podosphaera xanthii, microscopic observations of all tested samples revealed hyaline
conidia, ellipsoid to ovoid in shape, with fibrosin bodies, also the chasmothecia were exist in a high number, which contained only
one ascus with 3-8 ascospores, hayline appendages and globose. At least, the 9 local cultigenes tested they are susceptible to races 1
and 2US of Px under field conditions.

published in International Journal of Science and Technology Volume 5 No.

  • Determining the Magnitude of High Spot Lands by using Remote Sensing in Irrigated Schemes Case Study: Al Rahad Agricultural Scheme-Sudan

Abstract: High spot lands are one of the most serious problems facing the irrigated agricultural production sector of the Sudan. As well, water and wind erosion, and silt deposits are the major environmental hazards causing land degradation in most parts of the irrigated sector. An understanding of the extent and magnitude of these hazards on various field surfaces is essential for the selection of appropriate control
measures. The objective of this study was to identify and investigate the magnitude of high spot lands. Data from satellite images for four different years (1987-2013) were used to measure and quantify the high spot areas at four selected sites under the study areas.Also, personal communication with farmers in the study area was carried out.The satellite images showed variations of land cover in the study areas during years 1987-2013.The high spot lands covered 1.4 % of the total area till 1987 and increased to 3.3 %, 4.2% and 6.3 % in 2000, 2005 and 2013, respectively. Data from satellite images for the year 1987 and 2013 showed that the density of uneven spots in 2013 was higher than that in 1987.The analysis showed that some changes in orientationof Abu XXat some sites were initially made to accommodate some of the
natural elevation differences. The general trend of uneven area was randomly distributed. The results of the analysis of different remote
sensing data using GIS proved the presence of high spots and elevationdifferences within the scheme.It seems that the continuous plowing pattern by the ridger in most cases without considering elevation and slope differences have largely contributed in the creating more high spot lands by the transportation of the soil by the plowing implements. The laboratory soil analysis showed similar soil characteristics of samples collected from high spot lands compared with the nearby original soils of even areas. It can be concluded that high spot lands
increased at an annual rate of 0.2% and accordingly, it threatens agricultural production in the study area by the loss of potential yield of the left-out high spot areas. Detailed soil and land survey investigations based on remote sensing and GIS techniques are highly recommended to identify all high spot areas in the irrigated sector in terms of location, size and soil characteristics.

published in International Journal of Science and Research (IJSR)

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