Tuber Research Articles

DUAL BEHAVIOUR OF PLANTS AGAINST BACTERIAL QUORUM SENSING: INHIBITION OR EXCITATION

Bacteria use an unique and sophisticated system for regulating diverse physiological processes in function of their population size. This regulatory procedure, called “quorum sensing” (QS), depends on the synthesis and perception between bacteria of small signal molecules such as acyl-homoserine lactones (AHLs). It is now evident that plants can listen to bacterial signals and respond in sophisticated ways to the information. The anti-QS activity of the methanolic extract of 44 plant species was detected through the inhibition of the QS-related violacein pigmentation in Chromobacterium violaceum CV026 in the presence of 5 mgl-1 of C6- homoserin lactone. In addition, the ability of test plants to produce AHL-mimicking compounds that excite QS-related response in CV026 was investigated. The results revealed that the QS inhibition activity was observed in the leaves and stem extracts of tarragon (Artemisia dracunculus), radish (Raphanus sativus) and hollyhock (Althea officinalis), which repress violacein production in CV026. We have also shown that Trifolium repens contains AHL- mimicking molecules that can activate QS function in biosensor bacterium and induce violacein production in CV026. Methanolic extracts were also able to inhibit QS-regulated virulence in Pectobacterium carotovorum subsp. carotovorum on potato tubers. The results suggest that plants have quorum sensing-mimicking signals that could potentially be used for disrupting quorum sensing of associated bacteria thus controlling their infections.

Exposure risk assessment of plasticizer in dietary food in Xiamen

To understand the dietary consumption of residents in Xiamen and the content of phthalic acid esters (PAEs) in food, and to assess the plasticizer exposure risk of diet in Xiamen. The survey was conducted by stratified cluster random sampling method in Xiamen from September to October in 2010. According to the Xiamen administrative division, six neighborhood communities were selected as sampling units, then 25 families were randomly chosen from each sampling units.From the above 150 families, the permanent residents over the age of six were permitted to our study. The survey included 495 residents totally. These participants' information, such as basic personal information, physical activity levels, meal frequency and the average consumption of 33 kinds of food in 13 categories were collected using questionnaires. Thirteen categories included cereal and tubers, beans, vegetables, fungi and algae, fruits, dairy products, meat, seafood, eggs, snacks, beverages, cooking oil and spices. The height and weight of residents were measured and the average daily dietary intake was calculated. Thirty-three kinds of food in 13 categories were collected in supermarkets in Xiamen. According to the annual sales ranking, the top three-five brands of each kinds of food were selected and numbered, then two or three brands were chosen by random number table method from them; three completely individual packed samples in the same batch of each brand were detected; 243 samples were included in our study.100-500 g solid samples or 100-500 ml liquid samples were collected. The content of diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) in food were detected by liquid chromatography mass spectrometry, which expressed by median (minimum-maximum). The exposure dose, contribution rate and risk index of PAEs were calculated by point estimation method. According to the average daily dietary intake of residents in Xiamen, the top three ones in 13 categories of food were cereal and tubers (337.16 g/d, 18.21%), vegetables (309.12 g/d, 16.69%) and fruits (213.20 g/d, 11.51%). The content of DEP, DBP or DEHP among different categories of food was significantly different (χ² values were 58.05, 50.19 and 102.10, P < 0.01). Among 13 categories of food, seafood contained the most DEP (0.090 (0.000-0.324)mg/kg); cooking oil had the most DBP (0.700(0.000-2.980) mg/kg) and DEHP (5.115(0.000-24.160) mg/kg). DEP, DBP and DEHP exposure(0.19, 4.20, 18.10 µg × kg⁻¹ ×d ⁻¹)in dietary food in Xiamen were less than the reference dose(RfD) (800, 100, 20 µg × kg⁻¹ × d⁻¹) proposed by the United States Environmental Protection Agency (EPA), and the risk indexes were 0.02%, 4.20% and 90.50%, respectively. Among 13 categories of foods, seafood was the main source of DEP dietary exposure. The exposure dose and contribution rate of DEP in seafood were 0.18 µg × kg⁻¹ × d⁻¹ and 94.74%, respectively.Vegetables were the main source of DBP and DEHP dietary exposure. The exposure dose and contribution rate of DBP and DEHP were 1.48 µg × kg⁻¹ × d⁻¹, 35.24% and 6.07 µg × kg⁻¹ × d⁻¹, 33.54%, respectively. The food consumed by residents in Xiamen was overall in a safe state, but to some extent, there still exists DEHP exposure risk in foods.

Finite element modeling and comparison of fixation methods for acetabular fracture with involvement of the quadrilateral plate

Objective To compared different fixation methods for acetabular fractures involving the quadrilateral plate using a finite element model of the acetabulum.Methods A model of acetabular fractures with quadrilateral plate involved was developed in the finite element software and processed in Hypermesh V10.0 to generate internal fixation with dual-column titanium plate (Group A),anterior special titanium moulding plate plus quadrilateral screws (Group B),and anterior special titanium moulding plate plus quadrilateral screws combined with posterior column screws (Group C).Pelvic stress in sitting and standing positions were simulated in sequence with constraint of tuber nodes and inferior femur.Maximum stress and displacement of the acetabulum and displacement of nodes on fracture lines were measured after a force of 600 N was applied to S1 verterbrae in line with the direction of gravity in sitting and standing positions.Results In sitting position,the maximum stress and displacement of the acetabulum exhibited a sequence of Group C (9.47,1.08) ＜ Group B (19.84,1.11) ＜ Group A (29.73,1.14).Moreover,the same result was found in standing position with Group C (9.62,1.09) ＜ Group B (12.18,1.10) ＜ Group A (13.28,1.13).Mean displacement of nodes on fracture lines ranked in order of Group C ＜ Group B ＜ Group A (P ＞ 0.05).Conclusions The finite element model can reflect the distribution of pelvic stress effectively.Anterior special titanium moulding plate plus quadrilateral screws combined with posterior column screws provide favorable biomechanical stability in treatment of acetabular fractures involving the quadrilateral area. Key words: Acetabulum ; Fracture fixation, internal; Finite element analysis

LC-MS Quantification of Mangiferin in hydroalcoholic extract of Salacia oblonga, Salacia roxburghii and polyherbal formulation

Mangiferin is the one of the major active constituents in the tubers of the Salacia species, which is one of the valuable species in Ayurveda with antidiabetic, antihypertensive, hepatoprotective, anticaries and anticancer potentials. A simple and rapid liquid chromatography coupled mass spectrometry analysis was developed for the quantification of Mangiferin in two species of Salacia and also in polyherbal formulation. This method allowed the direct coupling of an electron spray mass selective detector for the LC system with photo diode array detector, Phenomenex C 18 column, acetonitrile and aqueous formic acid (0.5%) as mobile phase. Under these conditions, Mangiferin was well separated from the mixture of components present in the extract and detected with mass spectrometry (mass selective detector).Liquid chromatography coupled with electron spray mass was used in positive ion mode and detected at m/z 423(M+1) + . The proposed method is more accurate and sensitive can be used for the routine quantification of the Mangiferin in the herbal extracts as well as polyherbal formulations.

Cyperus esculentus - differences in growth and tuber production between cultivated and wild forms

Cyperus esculentus (yellow nutsedge) belongs to the world most important weeds on arable land. This species is classified as an invasive one in Central and North-western Europe. It is not yet present as a weed in the Czech Republic, but its occurrence in neighbouring countries and its ability to survive winters in this region must be taken into account. A cultivated form of C. esculentus, known as Chufa or Tiger nuts, is occasionally grown in home gardens as a crop for its edible tubers. In pot experiments we tested the growth of both forms, weedy and cultivated one. Weight of both fresh and dry biomass of plant parts (leaves, roots, rhizomes, tubers, inflorescences) was measured in monthly intervals from May till September 2012. Results show that there were no significant differences in leaf and root biomass. The weight of rhizomes was approximately 50-80 times higher in the wild form. Number of tubers was also higher in the wild form (max. 1118 pcs; crop max. 342 pcs in single pot), but the total weight of tubers was not significantly different. The cultivated form did not produce inflorescences at all, the wild form produced in average 13 inflorescences per plot. Based on our results we can state that growing of the cultivated form does not pose any risk – plants do not show intensive vegetative spread and do not produce inflorescences so crossing with the weedy form is not possible. The wild form can produce high amounts of rhizomes and tubers and is able to produce flowers under our conditions. That makes it a potentially dangerous weed in warmer regions of the Czech Republic.Keywords: Biomass production, crop, CYPES, invasive weed, yellow nutsedgeCyperus esculentus - Unterschiede in Wachstum und Knollenbildung zwischen Kultur- und WildformenZusammenfassungCyperus esculentus (Erdmandelgras) gehort zu den weltweit wichtigsten Unkrautern auf Ackerflachen. Diese Art ist klassifiziert als invasiv in Zentral- und Nordwesteuropa. Die Wildform kommt in der Tschechischen Republik nicht vor, aber in den Nachbarlandern. Ihre Fahigkeit, die Winter in dieser Region zu uberleben, muss berucksichtigt werden. Die Zuchtform von C. esculentus, als Chufa oder Tigernuss bekannt, wird gelegentlich in Hausgarten als Kulturpflanze wegen ihrer essbaren Knollen angebaut. In Gefasversuchen haben wir das Wachstum der beiden Formen, Wild- und Kulturpflanze, getestet. Frisch- und Trockenmasse von Pflanzenteilen (Blatter, Wurzeln, Rhizome, Knollen, Blutenstande) wurden in monatlichen Abstanden von Mai bis September 2012 gemessen. Die Ergebnisse zeigen keine signifikanten Unterschiede in der Blatt- und Wurzelbiomasse. Das Gewicht der Rhizome war bei der Wildform etwa 50- bis 80mal hoher. Die Anzahl der Knollen war in der Wildform ebenfalls hoher (max. 1.118 Stuck/Gefas) als bei der Zuchtform (max. 342 Stuck/Gefas). Das Gesamtgewicht der Knollen war nicht signifikant verschieden. Die Zuchtform bildete keine Blutenstande; die Wildform bildete durchschnittlich 13 Blutenstande pro Gefas. Basierend auf unseren Ergebnissen konnen wir feststellen, dass der Anbau der Zuchtform keine Gefahr ist, denn die Pflanzen zeigen keine intensive vegetative Ausbreitung und bilden keine Blutenstande, sodass die Kreuzung mit der Wildform nicht moglich ist. Die Wildform bildet grose Mengen an Rhizomen und Knollen und ist fahig, unter unseren Bedingungen zu bluhen. Das macht dieses Unkraut in warmeren Regionen der Tschechischen Republik potenziell gefahrlich.Stichworter: Biomasse-Produktion, CYPES, Erdmandelgras, invasives Unkraut, Knollenbildung

Bilateral Kalkeneal Apofiziti Bulunan Bir Olgunun MRG Bulguları

Calcaneal apophysitis (CA) is the most common cause of heel pain in patients before the ossification of calcaneal epiphysis. We report magnetic resonance imaging (MRI) findings of a case with bilateral CA. A 9 year-old male patient with bilateral foot pain was referred to our department for MRI. On bilateral foot MRI, bilateral decreased signal intensity on T1-weighted images, increased signal intensity on fat suppressed T2-weighted images that represents edema, subchondral erosions located tuber calcanei, insertion of Achilles tendon were detected. The diagnosis was bilateral calcaneal apophysitis. Sever's disease or CA is an inflammation of the calcaneal apophysis believed to be caused by repetitive microtrauma from the traction of the Achilles tendon on the unossified apophysis. It frequently occurs before or during the peak growth spurt and often shortly after a child begins a new sport or season. It is usually seen among 8-15 age group. Patients typically have no features such as swelling, skin changes, erythema, or other local abnormalities. Osseous erosion at metaphysis of the neighboring to calcaneal apophysis is the finding of CA on MRI. Similar signal difference may be seen at the secondary apophysial ossification centers.

Phytochemical composition, in vitro antioxidant and anticancer activities of quercetin from methanol extract of Asparagus cochinchinensis (LOUR.) Merr. tuber

Five compounds including quercetin (AC01), asparagine (AC02), sucrose (AC03), β-sitosterol-3-O-β-D-glucopyranoside (AC04) and β-sitosterol (AC05) were isolated from the methanol extract of Asparagus cochinchinensis (Lour.) Merr. tuber collected in Ba Ria–Vung Tau Province of Vietnam. Their structures were elucidated by NMR (1D and 2D-NMR). Quercetin (AC01) was subjected to the assay for antioxidant and anticancer activities. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay was employed for determining the antioxidant activity, while sulforhodamine B (SRB) method was applied for evaluating the anticancer activity against four selected human cancer cell lines. Quercetin had strong antioxidant activity with IC50 = 14.52 ± 2.12 µg/ml (as compared to standard vitamin C with IC50 = 10.49 ± 2.00 µg/ml). Meanwhile, quercetin (AC01) exhibited strong cytotoxicity against the HeLa, human cervical cancer cell line with IC50 = 5.78 ± 0.36 µg/ml, followed by lung cancer cell line (NCI–H460), lung cancer cell line with IC50 = 12.57 ± 1.19 µg/ml and liver cancer cell line (Hep-G2) liver cancer cell line with IC50 = 20.58 ± 0.85 µg/ml. The anticancer activity of quercetin against breast cancer cell line (MCF-7), breast cancer cell line was recorded with IC50 = 31.04 ± 3.14 µg/ml. Key words: Asparagus cochinchinensis, 1,1-diphenyl-2-picrylhydrazyl (DPPH), sulforhodamine B (SRB), human cervical cancer cell line (HeLa), lung cancer cell line (NCI-H460), breast cancer cell line (MCF-7), liver cancer cell line (Hep-G2).

Efficacy of selected Pseudomonas strains for biocontrol of Rhizoctonia solani in potato.

Thirty seven bacterial isolates from faba bean (Vicia faba L.) root-nodules were screened for their antagonistic activity against eight Rhizoctonia solani strains isolated from infected potato (Solanum tuberosum L.) tubers. Two bacterial strains (designated as Kl.Fb14 and S8.Fb11) gave 50% in vitro inhibition of R. solani mycelial growth. 16S rDNA sequence analysis indicated that strain Kl.Fb14 exhibited 99.5% identity with Pseudomonas moraviensis, and that S8.Fb11 exhibited 99.8% identity with Pseudomonas reinekei. Greenhouse trials in soil showed that strain S8.Fb11 reduced the percentage of sclerotia on potato tubers and amounts of tuber infection for the potato cultivars Spunta and Nicola. In a field trial conducted in South Tunisia, infection with R. solani reduced potato yield by approximately 40% for ‘Spunta’ and 17% for ‘Nicola’; about 20% of the total tuber production was severely infected. However, when potato tubers were treated with strain S8.Fb11 prior to sowing, disease incidence was reduced to 6% of total production with low infection levels; potato yield was enhanced by about 6 kg per 10 m row in comparison to R. solani infected plants. The second selected Pseudomonas sp. (strain Kl.Fb14) did not affect either the levels of sclerotia on tubers or potato yield.

Integrated nutrient management for growth and yield in Glory Lily (Gloriosa superba L.)

Gloriosa superba L. is an important medicinal plant species found in tropical and subtropical regions of India. Seeds and tubers contain colchicine which is used for treating gout, rheumatism and for producing polyploides. Due to diverse use, the species has been largely exploited from natural habitat leading to its threatened status. A field experiment was conducted to study the influence of organic and inorganic fertilizers on its growth and seed yield. Eight treatments including Control (T1), NPK at 120:50:75 kg/ha (recommended dose) (T2), FYM at 20 t/ha (T3), Vermicompost(VC) at 6 t/ha (T4), FYM at 10 t/ha + ½ T2 (T5), VC at 3 t/ha + ½ T2 (T6), FYM at 13.3 t/ha + â…“T2 (T7), VC at 4 t/ha + â…“T2 (T8) were followed to find their effect on growth and yield. The treatments were significantly different from each other and higher values were recorded for plant height (144.96 cm), number of leaves plant-1 (172.03), number of branches plant-1 (4.35), number of flowers plant-1 (30.50), number of fruits plant-1 (10.10), seed yield plant-1 (4.47 g) and estimated seed yield hectare-1 (197.50 kg) in the treatment VC at 4 t/ha + â…“T2. Available major nutrients (NPK) in soil also recorded higher after harvesting the crop in the treatment VC at 4 t/ha + â…“T2. Key words: Glory lily, inorganic fertilizers, organic manures, Gloriosa, seed yield.

Forest degradation and livelihood of local communities in India: A human rights approach

India’s current forest and tree cover is estimated to be 78.29 million ha, constituting 23.81% of the geographical area of the country. As per the India State of the Forest Report (ISFR) 2011, forest cover has declined by 367 sq. km compared to the forest cover in the preceding ISFR in 2009. The National Forest Commission report 2006 indicated that around 41 per cent of total forest in the country is already degraded, 70 per cent of the forests have no natural regeneration, and 55 per cent of the forests are prone to fire. In the forested landscapes of India, the livelihoods of the people, especially the indigenous communities, living close to forest and within the forests are inextricably linked to the forest ecosystem. People depend on the forest for a variety of forest products for food, fodder, agriculture, housing, and an array of marketable minor forest produces which can potentially degrade forest if harvested unsustainably. People living in these forest fringe villages depend upon forest for a variety of goods and services. These includes collection of edible fruits, flowers, tubers, roots and leaves for food and medicines; firewood for cooking (some also sale in the market); materials for agricultural implements, house construction and fencing; fodder (grass and leaf) for livestock and grazing of livestock in forest; and collection of a range of marketable non-timber forest products. Thus, this increasing degradation of forest is hampering the basic human right to life and livelihood of the local communities, especially the indigenous community whose life is closely linked with the resources and environment amidst which they live. Keywords: Forest degradation, human rights, local communities.

Wild edibles of Murari Devi and surrounding areas in Mandi district of Himachal Pradesh, India

The wild edibles served as a dietary supplement and medicine for thousands of years, particularly in the tribal and rural areas of the Himalayas. A total of 43 wild edibles, representing 33 genera and 25 families were reported. Maximum number of species were reported in the altitudinal zone, 700 to 1800 m followed by >1800 m altitudinal zone. Forty species were found in dry habitat followed by shady moist degraded bouldary, etc. Fourteen species were native to Himalayan region and the rest were non-native to Himalayan region. Various parts of these wild edibles, that is, fruits, leaves, roots, bark, flowers, seeds, tubers, aerial parts, etc., were consumed by the inhabitants for various purposes. Mass scale cultivation of such wild edibles in the villages may reduce the human pressure on the wild habitats. Therefore, conservation measures have to be taken to maintain the current status of these habitats and species. The information generated in the present communication represents a valuable database that provides baseline information and contributes to filling the knowledge gaps for the compilation of a local biodiversity register of the study area, a key instrument for achieving the regional and global biodiversity conservation and sustainable development goals. Key words: Wild edibles, Murari Devi, nativity, endemism, indigenous uses, Himachal Pradesh.

Study on Antioxidant Activity of Typhonium giganteum Engl. Tuber Extracts in vitro and in vivo

To study the antioxidant effect of the aqueous extracts of Typhonium giganteum Engl. tuber (AEoTGE) and ethanol extracts of Typhonium giganteum Engl. tuber (EEoTGE) in vitro and in vivo, which may be the possible mechanism of its bioactivity efficacy. The antioxidant activity in vitro was evaluated by 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging rate with Vitamin C as a positive control. The antioxidant activity in vivo was carried out to investigate the effects of AEoTGE and EEoTGE on D-galactose caused aging model mice by determining liver tissues’ superoxide dismutase (SOD) activities. The results indicated that AEoTGE and EEoTGE have good antioxidant activity in vivo and vitro. The antioxidant effect of AEoTGE is better than that of EEoTGE.

VARIABILITY OF POTATO SPINDLE TUBER VIROID ISOLATES FROM ORNAMENTAL HOSTS IN SLOVENIA

A survey of Potato spindle tuber viroid (PSTVd) was initiated in Slovenia in December 2006. Out of 398 samples collected between the beginning of the survey and the end of 2010, a quarter tested positive for PSTVd, in particular Brugmansia cordata (1), Solanum jasminoides (88), S. rantonnetii (5), Petunia spp (3), and S. muricatum (3). Analysis of 96 complete master sequences of Slovene positive samples revealed new variants, although the majority of master sequences were identical to the sequence variant of PSTVd found in S. rantonnetii in Italy (EF459700). A substitution of G to U at position 65 was found in several sequence variants otherwise identical to EF459700. The variability of this site was confirmed by cloning three samples that showed ambiguity at position 65 when the PCR products were sequenced directly. Phylogenetic analyses of Slovene sequence variants and sequence variants from GenBank showed two clearly separated clusters. High variability was observed within each cluster. Although most of the sequence variants from the same ornamental host tended to group together, sequence variants from the same hosts also showed high variability. On the other hand different hosts were found to be infected by the same sequence variant.

Conceptual instrumentation of washing machine for conformity to the Islamic laws of Syarak

The concept of today’s washing machine that uses control technology to clean clothing is based on clothing weight factor proportionately to the amount of water used irrespective of the nature of the contaminants. However according to Islamic law, clothing such as being contaminated with children’s urine for an example has to be cleaned using continuous flowing water especially during the initial stage of washing. With the concept of algorithm system and integrated into the washing machine, the continuous running water will be subjected during the initial wash and spin option. The light sensors used on both inlet and outlet valve will ensure the contaminated solids or liquids will be accordingly removed. Application of solenoid valve is used to control the water tank level during washing and drying period. Similar concept has been developed at Farm Unit, Department of Agriculture Science, UniSZA for removing the toxin from food tuber of Dioscorea hispida before it can consume securely. The analysis shows that using flowing new water will remove toxicity which was represent of excrement in clothing. This paper elaborates the concept of automatic washing machine operation which complies with Islamic law of syarak.

Effect of Host Stage on Parasitization and Biological Characteristics of Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae), A Parasitoid of Phenacoccus solenopsis Tinsley

The effect of host stage on parasitisation and biological characteristics of Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae), a parasitoid of Phenacoccus solenopsis Tinsley, was studied under laboratory conditions at 26-31°C and 46-73.6 per cent relative humidity. Mealybugs were reared on sprouted potato tubers and different stages of the pest were used in the host preference studies. Third instar and pre-reproductive adult females of the pest were most preferred by A. bambawalei for parasitization both under choice and no-choice conditions. First instars were not parasitized. Development of both male and female A. bambawalei was faster in large sized hosts (adult females). There was no significant difference in the adult emergence from different host stages. Emergence of adults from different stages ranged from 87.15 to 93.49 per cent. Maximum (73.39%) females emerged from reproductive adult females as compared to other stages of the pest. Parasitoid progeny emerging from second instar hosts consisted mostly (91.23%) of males.

Optimization of growth conditions and continuous production of inulinase using immobilized Aspergillus niger cells

Aim The aim of the study was the optimization of growth conditions for the production of inulinase as well as the continuous production of the enzyme in an airlift bioreactor using Aspergillus niger cells. Methods First, inulinase production by A. niger cells, using different carbon and nitrogen sources, was studied on a shake flask level. Second, the cells were adsorbed onto different carriers, and their production over several successive batches was tested. Finally, the economically-favorable continuous production of inulinase by A. niger cells immobilized onto linen fibers was carried out in an airlift bioreactor using crude inulin juice as the fermentation medium. Results Although all tested substances resulted in the biosynthesis of certain amounts of inulinase enzyme, the highest titer of 163.5 U/ml was obtained when the producing cells were incubated for 96 h at 27πC and 180 rpm in a fermentation medium containing both inulin and peptone as sole carbon and nitrogen sources, respectively. Moreover, when the cells of the tested microorganism were adsorbed onto different carriers, especially linen fibers, their productivity was also successfully maintained, to different extents, for five successive batches. However, as commercially pure inulin is very expensive and available in only small quantities, the fermentation medium was later substituted by a crude inulin extract obtained by mechanical crushing and filtration of Jerusalem artichoke tubers. The crude inulin juice was able to sustain inulinase production during the second batch cultivation of A. niger cells that were immobilized by their adsorption onto linen fibers to a satisfactory level of about 122 U/ml. Furthermore, the use of the previously mentioned crude inulin preparation was also compared with the use of either complete or minimal media, composed solely of 1% pure inulin, for the continuous production of inulinase enzyme by A. niger cells that were immobilized in their maximum production phase and packed inside an external loop airlift bioreactor. The results of this experiment were very encouraging as, using this technique, an inulinase production of about 838 U/ml over an incubation period of 48 h was obtained compared with a production of about 996 and 1013 U/ml, which resulted from the use of either minimized or complete media, respectively, for the same incubation period. Conclusion The method adopted in this study for inulinase production is simple, economic, time saving, and nontoxic to the microorganism. Moreover, the loaded linen fiber pads are reusable.

DYNAMICS OF PORCUPINE (HYSTRIX INDICA KERR) DIGGINGS: THEIR ROLE IN THE SURVIVAL AND RENEWAL OF GEOPHYTES AND HEMICRYPTOPHYTES IN THE NEGEV DESERT HIGHLANDS

ABSTRACT Porcupines dig as deep as 25–30 cm to obtain corms, bulbs, tubers, and underground parts of leaves and stems that they consume as food. Eighteen species of geophytes and hemicryptophytes were found to be consumed by porcupines in the Negev Desert highlands. Another 10 species inhabit these diggings, but they are not known to be consumed. Porcupine diggings in the Negev Desert were found to be important microhabitats in which runoff water and organic matter accumulate, improving conditions for germination, seedling establishment, and plant growth. The dynamics of the “recovery” of porcupine diggings (the rate of their covering) depends on topography, geomorphology, vegetation, and on the plant species inhabiting them. It is possible to differentiate among 3 patterns of “recovery” occurring in various localities: (1) porcupine diggings covered as a result of flooding as soon as the next rain comes; (2) diggings which may remain uncovered for more than 20 years; (3) an intermediate group of diggings...

L'évolution récente de l'agriculture brésilienne : entre enjeu alimentaire et globalisation

La constante am&#233;lioration quantitative (kcal/personne/jour) des niveaux de disponibilit&#233; alimentaire, observ&#233;e au Br&#233;sil depuis les ann&#233;es&#160;1970, s&#8217;accompagne d&#8217;une d&#233;gradation qualitative de l&#8217;&#233;quilibre nutritionnel. Celle-ci est li&#233;e &#224; une &#233;viction progressive de certains produits alimentaires de base (c&#233;r&#233;ales, l&#233;gumineuses et tubercules) par des produits nouveaux riches en sucres et en mati&#232;res grasses v&#233;g&#233;tales et fortement li&#233;s au secteur d&#8217;exportation. Face &#224; ces transformations r&#233;centes, le retour &#224; une approche analytique dualiste nous para&#238;t pertinent, puisqu&#8217;elle permet de caract&#233;riser la dynamique agricole sous-jacente &#224; ce processus de transition alimentaire.

Morphological, phytochemical, and anti-bacterial properties of wild and indigenous plant (Amorphophallus commutatus)

This study was undertaken to investigate the phytochemical and anti-bacterial properties of Amorphophallus commutatus var. wynadensis tubers using solvents of increasing polarity (viz: petroleum ether, hexane, and water). The chemical constituents of various extracts were obtained by the phytochemical analysis. For the anti-bacterial studies, both gram positive bacteria ( Streptococcus pyogenes , Streptococcus faecalis and Bacillus cereus ) and gram negative bacteria ( Enterobacter aerogenes, Escherichia coli, Salmonella typhi, and Proteus mirabilis ) were used. Among the various extracts, the petroleum ether extract (PEE) showed maximum zone of Inhibition (ZOI) against S. typhi and P. mirabilis with ZOI as 35 and 34 mm, respectively. The morphological aspects of A. commutatus are also present.

ASSESSMENT OF GENETIC VARIABILITY OF PREVALENT PECTINOLYTIC BACTERIA CAUSING POTATO TUBER SOFT ROT IN EASTERN IRAN

Pectobacterium carotovorum subsp. carotovorum (Pcc) is the causal agent of soft rot of potato tubers. This study was conducted to assess the genetic variation of a collection of 32 Pcc isolates from three different potato cultivars grown in the eastern parts of Iran using subspecies-specific PCR, 16S rDNA sequencing and rep-PCR analyses and comparing these methods with each other. In initial experiments, the identity of isolates was confirmed by specific primers related to Pcc subspecies and differentiated from closely species (P. wasabiae) using restriction enzyme analysis. All isolates were also checked for phenotypic properties and pathogenicity on potato tubers. Phylogenetic analysis, using clustering methods on partial sequences of the 16S rDNA, showed that all Iranian isolates grouped with the Pcc type strain (ATCC1571) except for six isolates from Kashmar. Based on rep- PCR cluster analysis of the pairwise similarity values using UPGMA, bacterial isolates could be separated into three clusters, the third of which (Kashmar isolates) was allocated in a distinct group. The similarity coefficients among strains ranged from 0.2 to 1. Rep-PCR primers disclosed different levels of genetic heterogeneity among Pcc isolates. No clear association was found between clustering based on rep-PCR and the geographical origin of the isolates, original host plant cultivars and the year of collection.