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Kosmos
Astronomia Astrofizyka
Inne

Kultura
Sztuka dawna i współczesna, muzea i kolekcje

Metoda
Metodologia nauk, Matematyka, Filozofia, Miary i wagi, Pomiary

Materia
Substancje, reakcje, energia
Fizyka, chemia i inżynieria materiałowa

Człowiek
Antropologia kulturowa Socjologia Psychologia Zdrowie i medycyna

Wizje
Przewidywania Kosmologia Religie Ideologia Polityka

Ziemia
Geologia, geofizyka, geochemia, środowisko przyrodnicze

Życie
Biologia, biologia molekularna i genetyka

Cyberprzestrzeń
Technologia cyberprzestrzeni, cyberkultura, media i komunikacja

Działalność
Wiadomości | Gospodarka, biznes, zarządzanie, ekonomia

Technologie
Budownictwo, energetyka, transport, wytwarzanie, technologie informacyjne

American Journal of Plant Physiology

Exogenous application of silicon (Si) in the form of potassium silicate at different concentrations (0.1, 0.2 and 0.3%) were investigated for maintaining quality and control disease development caused by Penicillium expansum on Anna apple fruits stored 60 days at 0°C±1 with 90-95% R.H (Experiment 1) and held for 6 days at room temperature conditions at 28°C±2 with 65-70% R.H (Experiment 2). It was noticed that the reduction in linear growth and dry weight were positively correlated to the increase in potassium silicate concentrations. So, potassium silicate at 0.3% treatment indicated complete inhibition of the linear growth and dry weight of P. expansum. The disease infection decreased as storage period advanced at cold storage and under marketing conditions. The lowest significant values of disease infection percentage of P. expansum were recorded by dipping fruit at potassium silicate at 0.3% after 60 days of cold storage and 6 days at marketing in the two seasons. Generally, significant changes were observed in potassium silicate at 0.3% which reduced the loss of weight, decay, total loss, respiration rate and PPO activity with respect to the other treatments or the control. Meanwhile, potassium silicate at 0.2% gave a higher fruit firmness. In addition, all silicon treatments reduced SSC, acidity, SSC/acid ratio and total sugar compare to the untreated fruits. The values of hue angle increased with the progress of potassium silicate concentration. These results show that potassium silicate can be used to delay ripening, keep quality and control disease development caused by P. expansum on apple fruits.

http://scialert.net/abstract/?doi=ajpp.2014.52.67 2014/07/25 - 10:20

Two field experiments were carried out during two successive seasons of 2011
and 2012 to study the effect of bio- and chemical fertilizers on growth, flowering
and some chemical analysis of Petunia Hybrida (cv. Bravo White). Petunia
plants were sprayed with Azospirillum lipoferum (nitrogen fixing bacteria,
N.F.B.) and Bacillus polymxa (phosphate dissolving bacteria, P.D.B.)
and their mixture in presence or absence of a complete fertilizer of 19N: 19P2 O5 : 19K2 O. Both bacterial inoculants and their mixture showed significantly
increases in the studied vegetative growth (i.e., plant height, branches number,
leaf area, dry weights of shoots and roots) and flower parameters (i.e. flowering
date, number of flower/branch and flowering period) when compared with the control
(full dose of NPK chemical fertilizer = 5 g plant-1 twice). Also
the results revealed that using Azospirillum sp. + Bacillus sp.
plus 5 g plant-1 of the chemical fertilizer produced the highest
significant values of all growth, flowering parameters and chemical analysis
(chlorophyll, total carbohydrates, N and P percentages) compared with the control.
It was clear that biofertilizers beside its ability to improve the nutrient
supply in the soil, they also increased the efficiency of added chemical fertilizer.
From the obtained results it can be used the half dose of the recommended chemical
fertilizer (2.5 g plant-1 twice) combined with each of nitrogen fixing
bacteria (at 2 mL L-1 twice) and phosphate dissolving bacteria (at
2 mL L-1 twice) to grow Petunia hybrid cv. Bravo White with
high quality, reducing the environmental from pollution and surpassed the recommended
dose of the chemical fertilizer.

http://scialert.net/abstract/?doi=ajpp.2014.68.77 2014/07/25 - 10:20

This experiment was conducted to evaluate the effects of priming on the germination, emergence and seedling growth of Abelmoschus esculentus (cultivar Marsaouia) under low temperature and salinity conditions. Seeds were primed for 24 h at 20°C in three priming media (KCl 4%, mannitol 0.75M, CaCl2 10 mM) and control (non-primed seeds) and were examined at different salinity levels (0, 40 and 100 mM NaCl). Results indicated that KCl priming increased final germination percentage, radicle length and seedlings dry weight 100%, 40.94 mm and 0.03 g, respectively, as compared with non-primed seeds. Mannitol and CaCl2 have been found to be better treatments for improving final emergence percentage. Overall increased NaCl level, led to the reductions in final germination and emergence percentage but these reductions were higher for non-primed compared to primed seeds. The increase in NaCl concentrations didn’t show any significantly effect on cotyledons fresh weight of primed or non-primed seeds. Besides, our results proved that priming alleviated the adverse effects of salinity for seedlings biomass as compared to non-primed seeds.

http://scialert.net/abstract/?doi=ajpp.2014.38.45 2014/05/18 - 20:58

In present study, effect of waterlogging (4, 8 and 12 days) on root anatomy
of ragi and rice was studied. It was noticed that the formation of aerenchyma
tissue in the ragi roots was induced due to increasing waterlogging treatment.
On the other hand, rice roots grown under normal conditions had well developed
aerenchyma tissue and treatment of waterlogging did not cause any noticeable
change in root anatomy. Thus development of aerenchyma in response to waterlogging
in ragi roots would certainly help to supply O2 to the root metabolism.
Activity of acid phosphatase was declined in both the species during waterlogging,
indicating that its involvement in aerenchyma formation was no any significance.
There was decline in calcium content in ragi roots due to waterlogging whereas
in rice root an increase was noticeable. Thus a decreased calcium level in ragi
roots may limit the availability of calcium for the formation of new cell wall
material.

http://scialert.net/abstract/?doi=ajpp.2014.46.51 2014/05/18 - 20:58

The effect of postharvest treatments with hot water (HW), gibberellic acid (GA3), salicylic acid (SA) and potassium permanganate (KMnO4) on enhancing or delaying the ripening quality aspect of mature Williams banana fruits were investigated. Untreated and treated fruit had a normal ripening process and similar good freshness at the ripening time (45 days at ambient temperature). This clearly that the used these materials were relatively in delaying ripening and as, can be arrange the appearance of banana fruits in the market with good quality. Such, color development, peeling condition, loss of firmness, increase of pulp/peel ratio, soluble solids content, titratable acidity, pH, total sugar and total starch were used as a good criterion of assessment the banana fruit ripening.

http://scialert.net/abstract/?doi=ajpp.2014.1.15 2014/03/28 - 21:44

The effect of postharvest treatments with hot water (HW), gibberellic acid (GA3), salicylic acid (SA) and potassium permanganate (KMnO4) on enhancing or delaying the ripening quality aspect of mature Williams banana fruits were investigated. Untreated and treated fruit had a normal ripening process and similar good freshness at the ripening time (45 days at ambient temperature). This clearly that the used these materials were relatively in delaying ripening and as, can be arrange the appearance of banana fruits in the market with good quality. Such, color development, peeling condition, loss of firmness, increase of pulp/peel ratio, soluble solids content, titratable acidity, pH, total sugar and total starch were used as a good criterion of assessment the banana fruit ripening.

http://scialert.net/abstract/?doi=ajpp.2014.1.15 2014/03/28 - 21:44

Ipomoea pes-caprae is a sand dune plant commonly used as folklore medicine
for fisherman communities based on the traditional knowledge. Little information
is available on the feasibility of applying micropropagation techniques for
production of dune and marsh species. The main aim of this study is to increase
the callus induction and shoot generation of sand dune plant Ipomoea pes-caprae
with easily available low cost natural materials. Coconut water is the rich
source of carbohydrate and other nutrients which enhance callus and plant regeneration.
In our present study, we tried different type of MS medium (Full and half strength)
with coconut water at three different percentage (10, 15, 20%) and different
concentration of plant growth regulators for callus induction and shoot regeneration.
Well-developed callus inoculated in full and half strength MS medium with different
concentration of CW and plant growth regulators. The best results were accomplished
with half strength MS medium with 15% coconut water and with 2, 4-D and IAA
0.7 mg L-1 concentration which shows better callus induction and
shoot regeneration. Young shoot and root developed plants transferred to green
house and then followed to soil.

http://scialert.net/abstract/?doi=ajpp.2014.16.23 2014/03/28 - 21:44

This experiment has been conducted to study antioxidant activities and biochemical
changes in round as well as long cultivars of brinjal. Results showed that maximum
protein content, amino acids, important minerals (Ca, P, K) and crude fibres
were recorded in Pusa Purple Round Pusa Purple Long. Maximum phenolic content
of brinjal fruit in round varieties was obtained in Pusa Purple Round followed
by Pant Rituraj and NDBH-1 (86.13 mg/100 g). Phenolic content was maximum in
Pusa Purple Long followed by Pusa Kranti and NB-2 in long varieties and Pusa
Purple Round in round varieties. A linear relation between the total phenolic
content and DPPH activities of the extracts was observed. Antioxidant activity
of brinjal fruit was noticed between (182.01-234.13 μg) in round varieties
and (172.11-219.92 μg) in long varieties. Maximum antioxidant activity
of brinjal fruit in round varieties was obtained in Punjab Bahar followed by
Pusa Purple Round and NB-1. However in long varieties of brinjal fruit it was
maximum in NDBH-2 followed by Pusa Purple Long and NB-1. While, lowest activity
was recorded in round variety NDBH-1 and Pant Samrat in long variety. On the
basis of biochemical investigation, it can be concluded that brinjal is very
nutritive and useful vegetable because it is rich source of protein, minerals,
crude fibre, phenolic content, antioxidant activity and important essential
amino acids.

http://scialert.net/abstract/?doi=ajpp.2014.24.31 2014/03/28 - 21:44

In this study the 21 days old seedlings of Pennisetum glaucum were subjected
to short term salt stress in order to observe the effect on chlorophyll content,
protein and antioxidative enzyme activity (CAT and APX) responses. The aim of
the experiment was to evaluate the changes in chlorophyll content and antioxidant
enzymes (Catalase and Ascorbate peroxidase). The 21 days old seedlings were
subjected to salt stress by supplementing Hoagland’s solution with different
concentrations of Sodium chloride (50, 100, 150 and 200 mM). Measurement of
chlorophyll content and antioxidant enzyme activity were taken at different
time intervals of salt treatment (12, 24, 48, 72, 96 and 120 h). The results
showed statistically significant differences in traits for the salt treatment.
A significant increase in Catalase activity was observed under all the salt
concentrations while no significant activity of Ascorbate peroxidase activity
was observed. The protein content and chlorophyll content decreased with increasing
salt concentration. This result shows salt stress affects the photosynthesis
rate by decreasing chlorophyll content. Catalase enzyme plays an important role
in scavenging reactive oxygen species generated due to salt stress in the plant
cell.

http://scialert.net/abstract/?doi=ajpp.2014.32.37 2014/03/28 - 21:44

During the last 15 years, many olive cultivars have been introduced in the
Kingdom of Saudi Arabia without any study on their biological and physiological
behaviour and characteristics. This work aimed to determine the floral biology
and the reproductive behaviour of five olive cultivars planted in Al-Jouf region
and to choose the right cultivars adapted to the agro-ecological conditions
of KSA. For each cultivar, floral biology in relation to phenological stages
and flower quality and fertility behaviour under self and free pollination were
determined for each cultivar. Notable significant differences between the cultivars
were observed in all characteristics considered. Among the productive characters,
all the olive cultivars showed a good productive behaviour with particular interest
for ‘Picual’ and ‘Sourani’ cultivars. Regarding pollen characteristics,
‘Sourani’ and ‘Picholine’ reflected better pollen quality
while the evaluation of flower quality and bloom showed good performance in
all cultivars except for ‘Zaiti’ and ‘Nabali’ cultivars.
In all cultivars, a positive response to open pollination was significantly
consistent when compared with self pollination. The self-incompatibility index
ISI was higher than 0.5 for all cultivars classified them as partially self
incompatible cultivars. These results suggest that the five olive cultivars
performed well in Al-Jouf conditions with a high phenological variability between
cultivars for the parameters evaluated.

http://scialert.net/abstract/?doi=ajpp.2013.93.104 2013/12/30 - 23:30

Lake Naivasha and its environs experienced increased levels of pesticide application
due to the rapid expansion in floriculture farming. Previous studies had shown
detectable levels of Organochlorine pesticide residues in water samples. The
Lake is under threat since such occurrences are linked to the poor water quality.
Moreover, Organochlorine pesticide residues persist in the environment while,
the Organophosphate pesticides which had been adopted as an alternative to Organochlorine
pesticides were highly toxic. The study investigated the occurrence and effects
of Organochlorine and Organophosphate pesticide residues on water quality. The
specific objectives of the study were: To determine water physico-chemical parameters
and investigate pesticide residues concentration of Organophosphate and Organochlorine.
Longitudinal study design was used during the months of February to July, 2011.
The sampling sites were selected on the basis of their relevance as point sources
of pesticide contamination. Three replicates of water samples were collected
monthly, 18 water samples per site, totaling to 90 samples. These samples were
subjected to water quality analysis and Gas Liquid Chromatography technique.
The data generated were subjected to analysis while applying Statistical Package
of Social Science using one way ANOVA at p<0.05. The results revealed that
the water samples tested were in compliance with World Health Organisation and
Kenya Bureau of Standards recommended guidelines while, Organochlorine and Organophosphate
pesticide residues were not detected. It was concluded that the lack of these
pesticide residues was due the current conservation measures preventing water
pollution in the Lake. The study further, recommended continuous monitoring
and conservation measure to be maintained.

http://scialert.net/abstract/?doi=ajpp.2013.105.113 2013/12/30 - 23:30

The phytochemical screening and antioxidant properties of the leaves of Ormocarpum
cochinchinense L. were studied after extraction of various compounds in
it using different solvents. The different solvents used for extraction was,
dimethyl sulfoxiamide (DMSO), Ethyl Acetate (EtoAc), ethanol (EtOH), methanol
(MeOH) and chloroform (CHCl3). Antioxidant potential was evaluated
by using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity.
The DMSO, EtoAc, EtOH, MeOH, CHCl3, extracts showed significant (p<0.001)
antioxidant potentiality in a dose-dependent manner. Its IC50 values
(13.05±0.39; 14.08±0.42; 15.02±0.45; 16.12±0.48;
14.88±0.44 μg mL-1) were compared to the IC50
value of the reference standard ascorbic acid (06.10±0.18; 07.18±0.21;
08.15±0.24; 09.10±0.27; 08.18±0.23 μg mL-1)
which suggested that the Ormocarpum cochinchinense is a potent antioxidant.
The phytochemical evaluation indicated the presence of chemical constituents
including flavonoids, alkaloids, steroids, terpenoids, saponins, gums, tannins,
resins, coumarins, glycosides, carbohydrates. This study also shows that the
different solvent extract of leaves of O. cochinchinense has bioactivity.
Further the compound needs to be isolated to confirm the activities of the individual
compounds.

http://scialert.net/abstract/?doi=ajpp.2013.114.122 2013/12/30 - 23:30

Chromosomal studies were carried out on Eichhornia crassipes and the taxon was found to have 32 individual chromosomes with a haploid chromosome number of 16 (n = 16), indicating a clear tetraploid genome of 2n = 4x = 32. Chiasmata frequencies per nucleus/bivalent were analyzed at diplotene and diakinesis revealing a marked reduction of chiasmata at diakinesis as compared to diplotene. The very low terminalization value of 0.43 showed that most of the chiasmata were terminalized at diakinesis and metaphase I. Multivalent associations were frequent suggesting the presence of a translocation heterozygote. Univalents were also of a frequent occurrence. Chromatid bridges, fragments, laggards and eliminated chromosomes were also frequent at both MI and MII. Secondary association of chromosomes occurred with a preponderance of four and eight over other groups. The occurrence of secondary associations and other aberrations were suggestive that Eichhornia crassipes is of hybrid origin. Cytological studies of Eichhornia crassipes revealed that chromosome behaviour which includes high frequency of chromatid bridges formed (42.52%), high percentage of univalents (15.24%) and the presence of phragmoplast during microsporogenesis does not influence the prolific behaviour of the plant.

http://scialert.net/abstract/?doi=ajpp.2013.50.62 2013/07/01 - 11:25

Enzyme activity depends largely on environmental conditions such as temperature
and pH. The stabilities of Polyphenol Oxidase (PPO) extracted from Solanum
melongenas and Musa sapientum fruits pre-incubated in varying thermal
and pH conditions were carried out. Enzyme activity was measured by spectrophotometric
methods. The reaction mixture contained 3.5 mL of 0.20 M phosphate buffer (pH
= 6.8), 1.0 mL of 0.75 mM catechol and 0.5 mL of enzyme solution. PPOS.
melongenas and PPOM. sapientum gave different temperature
and pH optima. The temperature-activity profile of PPOS. melongenas
and PPOM. sapientum showed a strong positive correlation
(r = 0.907363). At pH = 10.0, PPOM. sapientum activity represented
65.3% decay in enzyme activity, whereas PPOS. melongenas represented
79.3% decay in enzyme activity. PPOS. melongenas and PPOM.
sapientum stability at pre-incubated temperatures of 20, 50 and 60°C
and pH values of 3.5, 6.0 and 8.0 were measured. Residual activities of PPOS.
melongenas and PPOM. sapientum showed a strong positive
correlations under the same experimental thermal conditions, with exception
at 20°C (r = 0.693375). Specifically, pre-incubation of PPOM. sapientum
for t = 90 min at 60°C caused 18.4% decay in relative activity of PPOM.
sapientum. At t = 90 min, pre-incubation of PPOM. sapientum,
in pH = 3.5 caused decay in activity within the range of 30.8-36.1%, whereas
PPOM. sapientum pre-incubated in pH = 6.0 and pH = 8.0 gave
decay in activity within the range of (1.5-9.8%) and (2.7-6.5%), respectively.
PPOS. melongenas and PPOM. sapientum showed
relatively higher stabilities as the incubation pH tended towards alkaline conditions,
whereas the two experimental temperatures (20 and 60°C) promoted destabilization.

http://scialert.net/abstract/?doi=ajpp.2013.63.73 2013/07/01 - 11:25

‘Arbequina’ olive cultivar which is the most grown for high quality
olive oil in Spain, has the potential for being cultured in KSA. The aim of
this study was to investigate the efficiency of inorganic and organic growing
substrates on the root growth and the root morphology of Arbequina olive cuttings.
One-year-old cuttings were dipped in IBA 4000 ppm before planting in 3 substrates:
sand, perlite (inorganic) and peat moss (organic). The results showed that IBA
(1H-indole-3-butyric acid) at 4000 ppm combined with perlite substrate were
successful in promoting earlier root development and limited callus formation
in the early period of rooting. Cuttings rooted more profusely on perlite substrate
and developed significantly more and longer roots per cutting. Also best survival
and easily acclimatization of plants in greenhouse was unregistered. On the
contrary, peat moss developed a root system with high callus and proved to be
less qualitative with less number and shorter roots per cutting, suggesting
that peat moss was not a suitable environment for adventitious root formation
of Arbequina cultivar. Good callus formation was also obtained with untreated
control cuttings where late emergence was observed. Roots of cuttings necrosed
and died by the end of growing period. Considering all studied aspects of root
system, the physical properties of substrates should be carefully choose as
rooting medium of olive cuttings.

http://scialert.net/abstract/?doi=ajpp.2013.74.83 2013/07/01 - 11:25

Largely, kinetic properties of Polyphenol Oxidase (PPO) involved the study of enzyme extracts obtained from whole fruits and vegetables. In the present study, PPO was extracted from three segments of Solanum melongenas and Musa sapientum fruits and partially purified. The specific activity of PPO was measured at each purification step to ascertain level of enzyme purity. In all cases, PPO conformed to Michaelis-Menten kinetics, showing different values of kinetics parameters. Michaelis-Menten constant for PPO (PPOKm) of S. melongenas mid-section and anterior segments showed no significant difference (p<0.05), whereas the posterior gave PPOKm = 4.6±0.49 mM (p>0.05). Maximum PPO activity (PPOVmax) was highest in the posterior segment: PPOVmax = 0.602±0.09 U. Mid-section of M. sapientum exhibited the highest Km value (PPOKm = 5.8±0.69 mM) compared with the anterior (PPOKm = 3.9±0.69 mM) (p>0.05) and posterior PPOKm = 4.9±0.11 mM segments (p<0.05). Overall, M. sapientum PPOKm values were relatively higher than those of S. melongenas. Posterior S. melongenas exhibited the highest PPOVmax = 0.602±0.09 U, whereas the lowest value was registered in the anterior segment of M. sapientum PPOVmax = 0.234±0.09 U. Substrate specificity for PPO (PPOVmax/Km) extracted from various segments of S. melongenas was in the increasing order of Mid-section > Posterior > Anterior, whereas that of M. sapientum was Mid-section > Anterior > Posterior. PPOVmax/Km between the two fruits showed strong positive correlation (r = 0.862339). Catechol was a better substrate for PPOS. melongenas than PPOM. sapientum. The experimentally observed kinetic parameters of S. melongenas and M. sapientum signified the presence of PPO isoenzymes and non-uniform distribution of PPO in the two fruits.

http://scialert.net/abstract/?doi=ajpp.2013.84.92 2013/07/01 - 11:25

An agroecosystem is considered a large stationary source where CO2 can be captured from emissions through carbon stock in both crop plants and the soil. The aim of this study was to evaluate seasonal changes in the quantity of carbon effluxes and stocks in the vineyard agroecosystem. Three different vine ages (5, 10 and 18 years) were used to estimate the seasonal dynamics of CO2 effluxes and stocks in both the grapevine and soil parts during the 2011 growing season. This study shows that daily carbon gain and carbon use efficiency to daily climatic and soil variables were varied among vine ages throughout the season. In addition, the seasonal carbon stock in vine dry matter production was significantly increased from the youngest to oldest vines, being highest in the 18 year old vines. The decomposition rate of organic carbon from litter and residues also showed significant differences among vine sites and seasonal changes. Despite the different carbon stocks in the vine biomass among the three vine ages, the amount of total soil organic carbon mostly remained stable among the three vine sites. The relationship between vine ages and total carbon stock in the vineyard could then be estimated by fitting a power function (y = 36.72x0.2577, r2 = 0.998*). This study indicates that carbon effluxes and the potential carbon stock in the vineyards fluctuated seasonally according to vine ages.

http://scialert.net/abstract/?doi=ajpp.2013.1.16 2013/05/18 - 19:49

The interactions of bicarbonate (HCO3¯) and different nitrogen sources in the non-diazotrophic cyanobacterium Spirulina platensis in terms of pigments content, photosynthetic O2 evolution, Ca++-dependent ATPase activity and cytochrome c oxidase activity were examined in the present investigation. The cyanobacterium was acclimated to 300 mol m-3 HCO3¯-concentrations in the growth medium containing no nitrogen. The addition of different nitrogen sources in the growth medium resulted in further acclimatization up to 400 mol m-3 HCO3¯. This finding revealed that nitrogen sources incorporated into necessary metabolites, nitrogen storage material and photosynthetic pigments as well. The combined transport of HCO3¯and nitrogen sources ultimately resulted in gradual increase in the examined parameters in order of NO3¯<NH4+<urea. Nitrate and ammonium assimilating enzymes i.e., Nitrate Reductase (NR) and Glutamine Synthetase (GS) were also examined in graded concentration of HCO3¯ and the findings suggested that both the enzymes showed higher activity in the medium containing higher HCO3¯ concentration this suggested that the activity of these enzymes closely linked with carbon fixation. Further, we examined the Ca++-dependent ATPase activity and cytochrome c oxidase activity in the presence of graded concentration of HCO3¯. The enzyme was more active in the presence of high HCO3¯ concentration; the co-existence of NADPH further enhances the enzyme activities. The use of such cultural practices would help in mass production of biopigments on industrial scale and would paved the way for the development of new technology for CO2 fixation using the solar light as the energy source.

http://scialert.net/abstract/?doi=ajpp.2013.17.31 2013/05/18 - 19:49

Nitrogen fertilization under salinity stress is of main concern to be investigated, especially in the arid and semiarid regions. Pot experiment was conducted in the greenhouse of the "Micronutrient Project", Fertilization Technology Department, National Research Centre, Dokki, Cairo, Egypt with Wheat (Triticum aestivum L. var. Gemieza9 ). Plants were grown on sandy soil under salinity stress to study their response to soil application of different nitrogen sources compared to those irrigated with tap water. Nitrogen fertilization was added to the pots in the rate of 168 kg N ha-1 as urea, ammonium nitrate, calcium nitrate or ammonium sulfate. Fifteen days after sowing, half of the pots of every treatment were irrigated regularly with tap water (S1) and the other half was irrigated with saline water (S2). Results showed that salinity stress of irrigation water significantly inhibited growth parameters in terms of plant height, fresh weight and dry weight accumulation. Nitrogen form significantly interacted with salinity stress of irrigation water. The highest reduction in all determined parameters was recorded with urea, while very slight or none with calcium nitrate. Macro- and micro-nutrient concentration and uptake by wheat shoots were significantly affected by salinity stress of irrigation water. The best uptake of almost all determined nutrients was achieved by calcium nitrate fertilizer, especially under salinity stress conditions. Thus among the used N- forms, calcium nitrate is the best nitrogen form can alleviate the harmful effects of saline ions and realizing good plant growth under salinity stress of irrigation water.

http://scialert.net/abstract/?doi=ajpp.2013.32.40 2013/05/18 - 19:49

In order to enhance the establishment of olive plantation in the Kingdom of Saudi Arabia (KSA), an investigation was carried out to improve the rooting ability of olive cuttings. This research aimed to study the effect of three substrates (sand, peat moss, perlite) and IBA treatment (at 0 and 4000 ppm) on rooting ability of three olive cultivars (Arbequina, Koroneiki and Picual). The percentage of cuttings that rooted, the number of roots produced by cutting, the average root length and the survival rate were recorded. These parameters were significantly influenced by the interactive effect of substrates, cultivars and IBA treatment. The semi hardwood cuttings planted in perlite and sand had higher rooting percentage than those planted in peat moss with a significant difference between cultivars. Very low rooting occurred in cuttings dipped in distilled water (control) for all cultivars and in all substrates. At 4000 ppm IBA, Arbequina and Koroneiki cultivars gave high results while Picual cv. recorded worst performance in all the substrates tested. Results in relation to the physical properties of the substrates used in this experiment were also discussed.

http://scialert.net/abstract/?doi=ajpp.2013.41.49 2013/05/18 - 19:49

Adventitious root formation in woody plants is highly influenced by the process of physiological ageing. There are increasing efforts to identify markers for distinguishing between mature and juvenile stages of trees. However, it appears to be very little information on this aspect at the chemical and molecular levels. The aim of the work was to identify potential chemical marker of juvenile and mature state; and accomplish maximum rooting in teak (Tectona grandis Linn. f.) leafy shoot cuttings. Experiments with teak leafy shoot cuttings of three different physiological ages 30- and 15-year-old (mature); and 2-month-old (juvenile) were conducted in mist propagation system. Maturity of donor teak plants decreased rooting ability. Cuttings obtained from 2-month-old donors rooted more profusely in comparison to 15- and 30-year-old donors. Indole-3-butyric acid treatment at 4000 mg L-1 significantly increased rooting percentage and produced highest number of roots. High Performance Thin Layer Chromatography (HPTLC) analysis of anthraquinones (AQs; C14H8O2) was utilized to detect qualitative and quantitative differences in AQs in stem tissues from 2-month, 15- and 30-year-old donor plants. The HPTLC analysis showed that AQs varied from 2.8 to 18.3% in cuttings derived from 2-month-old donor plants, while the variations were 4.9 to 27.3% and 11.8 to 43.4% in those from 15- and 30-year-old donor plants, respectively. Altogether, data support that AQs could be a reliable marker for maturity vis-à-vis juvenility in teak.

http://scialert.net/abstract/?doi=ajpp.2012.220.231 2013/01/24 - 02:48

Regarding the influences and consequences of abiotic stress, dry weather is
one of the major causes of crop losses worldwide. The aim of this study was
to test the adaptation potential of sweet orange (Citrus sinensis L.
Osb.) in dry environmental conditions with a high vapor pressure deficit. Two
different soil moisture levels were used in a pot trial for sweet orange seedlings
in greenhouse conditions. One year old citrus seedlings, which are grown as
exotic plants in semi-arid regions, were studied under moist soil conditions
and during mild soil water stress. Higher leaf gas exchange and physiological
response values were found for the well-watered soil condition. However, no
difference in the total chlorophyll content was observed. In addition, photosynthetic
functions were very different in response to soil water status. However, no
significant differences were found between the soil water levels for thylakoid
light harvesting and leaf carbohydrate content. In addition, there were significant
differences in biomass partitioning between the well-watered seedlings and the
mildly stressed seedlings. Consequently, the total dry mass difference in the
entire citrus seedlings was approximately 40% for both soil water levels. This
study indicates that citrus seedling could adapt to survive and grow in dry
weather conditions with a sufficient soil water supply. The drought stress tolerance
of citrus varieties and their adaptation and growth in semi-arid regions are
discussed.

http://scialert.net/abstract/?doi=ajpp.2012.232.242 2013/01/24 - 02:48

Mango production in Ghana is highly reduced by low fruit set. This research was undertaken to apply plant growth regulators to increase fruit set and yield. The present investigation was carried out during two successive years of 2008 and 2009 on “Keitt” mango trees in order to study the effect of gibberellic acid (GA3) and Naphthalene Acetic Acid (NAA) sprays of different concentration on fruit retention, fruit quality and yield. Trees were sprayed at full bloom stage. The three hormone levels and two location effects were factorially combined and replicated three times in a Randomized Complete Block Design (RCBD). In order to obtain season or year effect, data were analysed as a split-split plot design with season as the main plot, location as sub-plot and cultivar as sub-sub plot. All sprayed chemicals significantly increased fruit retention and tree yield in both seasons. GA3 (25 ppm) and NAA (25 ppm) gave the best results in terms of increasing fruit set, fruit retention, number of fruits per cluster and per plant, fruit weight and yield. No significant differences were observed between the quality of fruits harvested from treated and control trees. 25 ppm of GA3 and 25 ppm NAA can be employed for spraying mango flowers at full bloom to increase mango fruit set, retention and yield of growers.

http://scialert.net/abstract/?doi=ajpp.2012.243.251 2013/01/24 - 02:48

Chilling injury is when morphological and physiological damage is sustained by plant tissue that is exposed to freezing temperatures. An experiment was conducted using four chilling tolerant sweet potato genotypes such as 105MS1, 108MS2, 180MS3 and 183MS4, which were selected from seventy nine lines from three major variety crosses for tolerant to chilling injury. The effects of chilling exposure on fatty acids compositions and peroxidase enzyme activity were studied. Chilling exposure increased the Peroxidase Enzyme Activity (PEA). Genotypes differences were also found in PEA following chilling exposure. All four genotypes that were tested had a high level (over 50%) of unsaturated fatty acid on their glycolipids. There were no differences found for the fatty acid percentage composition of the total glycolipid and phospholipid fractions from the four chilling tolerant genotypes except for C18:0 of the glycolipid fraction. However, C18:0 was found in low percentage and was not considered a major fatty acid. Sixty percent of total fatty acid in glycolipid fraction was C18:2 and C18:3. It was concluded that if lipids fatty acid composition was indeed a factor in chilling tolerance, it did not vary among the chilling tolerant genotypes. The result suggests that the genotypes were considered chilling tolerant to chilling environment, but that differences existed in their mechanism for tolerance. Thus, by breeding and selecting for chilling tolerance, it could enhance chilling tolerance in sweet potatoes.

http://scialert.net/abstract/?doi=ajpp.2012.252.260 2013/01/24 - 02:48

Damsisa (Ambrosia maritima L.) is one of the wild plants present in
Egypt and different African countries of the Nile Valley. It considered as potential
source of molluscicides for treatment of infected sites. In this study, DNA
amplifications technique and protein electrophoresis were used for the evaluation
of response of Damsisa herbs to gamma rays (γ-rays), soil salinity and
their interaction on alleviation of salt stress. This study also examined the
effect of herb as bio-resistant for insect infestation in Phaseolus beans.
Protein electrophoresis revealed that the number of protein bands separated
from plants grown in saline soil not changed either grown from irradiated or
un-irradiated seeds except 40 Gray (Gy) dose. Meanwhile, it was observed that
mixing Damsisa herb with infested Phaseolus beans reduced insect ability
to lays eggs or complete life cycle. Also, it was found that herbs produced
from irradiated seeds and grown in normal or in saline soil were more effective
in destruction of Callosobruchus maculatus insect and decreased the loss
from infested beans.

http://scialert.net/abstract/?doi=ajpp.2012.261.268 2013/01/24 - 02:48

Plant growth and seed germination are severely affected by saline conditions. Local tomato cultivars could be better adapted to salt stress. For this reason, to test that, the effect of four levels of salinity (0, 50, 100 and 150 mM NaCl) on seed germination, plants growth (relative fresh and relative dry weight), K+ and Na+ content and photosynthetic rate of the four local cultivars (Heb, Ram and J1) and one commercial cultivar (Mar) was studied. Significant difference in G50 of Heb cultivar was seen at 50 and 100 mM NaCl when compared with the other four cultivars (p<0.05) and the only one achieved 50% germination at 150 NaCl. Salt stress reduced plant growth of all cultivars, but Ram and Mar cultivars were characterized as the most tolerant and sensitive, respectively. No significant difference was seen in K+/Na+ ratio among four cultivars tested, but Ram showed the maximum value of 5.72 and 35.09 at 50 and 100 mM NaCl, respectively. Ram also showed better photosynthesis rate (5.1, 3.71) at 50 and 100 mM NaCl, respectively, than the other four cultivars.

http://scialert.net/abstract/?doi=ajpp.2012.269.275 2013/01/24 - 02:48

The imbalance between land use for agronomy and for earth mineral exploration has profound ramifications for food security in gold producing African countries. Mineral exploration within forest ecosystems is a common phenomenon across the Sub-Sahara African region. This case study of Ghana examined the conversion of fertile agricultural land to gold mining land and how this change impacted on cropland area. Between 1980-2000 the mining land area within the four major gold-producing centers of Ghana increased by a total of 1131.61 km2. Surface mining operations represented the major cause for land use change from cropland to mining land. There were simultaneous increases in the land area for food crops and cash crops. This seriously limited the land area available for food production. Though inter-annual food harvest increased, it resulted from the expansion in farm size rather than from improvement in technology or agricultural inputs. Increased gold production generated higher income to support food imports. However, the high cost of imported food undermined the food purchasing power of rural people. Rural poverty rate between 1980 and 2000 increased while urban poverty percentage remained 15%. Uncontrolled gold mining could facilitate a rapid decline in arable land area and reduce the food crop production output. This imbalance in land use could contribute to long-term food security crisis in Ghana and other gold-producing Sub-Sahara African countries.

http://scialert.net/abstract/?doi=ajpp.2012.184.199 2012/10/06 - 05:53

A study was carried out to determine the effect of planting date on Cassava Mosaic Disease (CMD) transmission by white flies (Bemisia tabaci) and its development in a population of cassava clones selected at Lomé Agricultural Experimental Station (LAES) of the High School of Agriculture, University of Lomé in order to contribute in the search of a strategy of effective control of CMD in Togo. To achieve this goal, cassava clones resulting from seeds of the third generation (F3) were planted at different dates on plots P1, P2 and P3 with the interval of 21 days. Three weeks after the establishment of the planted seedlings, data assessment was initiated weekly during twenty weeks. And the measured parameters were: (i) weekly counting of whitefly population on seedlings per plot of 114 m2 and (ii) weekly visual observation to quantify the diseased seedlings according to an assessing note on the severity of the disease ranging from 1 to 5. The results obtained from the visual observations made during this study, revealed that the propagation of the disease on each plot of the evaluated clones is proportional to the size of the population of vectors in presence. Thus, three months after plantation, it was numbered 53% diseased individuals (p<0.05) among the population of cassava clones; at the same time, the population of whiteflies reached an average 1.49±5.23 to 7.83±12.81 individuals by cassava seedlings under the conditions of this work. It was observed that the most significant number of whiteflies was noted on the plots P2 and P3. It was noticed that the plot P3 which was installed six weeks after plot P1, 41% of the seedlings died (p<0.05) due to the infestations of eggs and the larvae of whiteflies.

http://scialert.net/abstract/?doi=ajpp.2012.200.211 2012/10/06 - 05:53

Salinity is considered the most important abiotic stress, which limits growth and productivity of plants and degrades agricultural soils in arid and semi arid areas. The study was conducted on Vicia faba L. 'Semilla violeta' and ‘Reine mora’. Sowing was carried on plastic pots containing sandy substrates of bentonite 3, 5, 7 and 10% which corresponded salinity doses of NaCl, MgCl2 and MgSO4 20, 40 and 60 mmol L-1, respectively. Saline effect was investigated on germination and proline content. Results showed that the addition of 5% of bentonite improved the germination rate and time. However, the combined effect of salinity and bentonite showed a relatively increase of proline in ‘Reine mora ' than those of 'Semilla violeta'.

http://scialert.net/abstract/?doi=ajpp.2012.212.219 2012/10/06 - 05:53

Although, the ripening of climacteric fruits such as bananas is known to be mainly triggered by ethylene, cytokinins may also intervene in the control and regulation of this process. Bananas were treated by dipping for 24 h in solutions of cytokinins at concentrations ranging from 10-6 to 10-3 M to determine effects of these phytohormones on some parameters during the fruit ripening. At all concentrations used, benzylaminopurine induced significant retentions of water in the peel of banana fruits. Only 10-3 M kinetin solution was significantly effective in inhibiting the decrease of water content in the peel. There was an inhibition of the accumulation of water in the pulp of bananas after treatments with kinetin or benzylaminopurine. Qualitative analysis of pigments in peel extracts revealed an inhibition of chlorophyll degradation after application of cytokinins. Thus, banana fruits treated with 10-3 M kinetin still contained only chlorophyll a whereas, fruits treated with 10-3 M benzylaminopurine contained both chlorophyll a and chlorophyll b at ripening stage 7. At this ripening stage, no chlorophyll could be detected in extracts from the peel of control fruits. There were increased accumulations of monoacylglycerol, triacylglycerol and free fatty acids in the peel of banana fruits treated with 10-3 M benzylaminopurine. Contrarily to apolar lipids, no remarkable effects of treatments of bananas with 10-3 M benzylaminopurine on polar lipids could be observed. These results indicated that cytokinins modulated the metabolism of photosynthetic pigments and lipids and changes in the water content and that chlorophyll b was converted into chlorophyll a before its degradation in the peel of banana fruits during the ripening process.

http://scialert.net/abstract/?doi=ajpp.2012.154.163 2012/05/17 - 20:28

Significant differences in the antioxidant system of the leaves of four chickpea
(Cicer arietinum L.) genotypes differing in tolerance to drought were
observed in a pot experiment. Drought stress was imposed at pre- and post- anthesis
stage (50 and 65 days after sowing). We studied the effect of drought stress
on hydrogen peroxide (H2O2) content, lipid peroxidation
and antioxidant enzyme activities in four chickpea genotypes viz., Tyson, ICC
4958, JG 315 and DCP 92-3. Drought treatment significantly increased hydrogen
peroxide accumulation and lipid peroxidation, which indicated the extent of
oxidative injury posed by stress conditions. Enzyme activities of Superoxide
Dismutase (SOD), Peroxidase (POX), Catalase (CAT) and Ascorbate Peroxidase (APX)
increased in chickpea leaves as a consequence of drought conditions and all
the enzyme activities were significantly higher in drought stressed genotypes
i.e., Tyson and ICC 4958 than in JG 315 and DCP 92-3. Relationship between Lipid
Peroxidation (LPO), Hydrogen peroxide (H2O2), Superoxide
Dismutase (SOD), Catalase (CAT), Peroxidase (POX) and Ascorbate Peroxidase (APX)
was determined in order to find out whether these parameters can be used as
selection criteria for drought tolerance in this crop. Early drought stress
(pre-anthesis drought) was found to be more damaging than the late drought stress
(post-anthesis drought).

http://scialert.net/abstract/?doi=ajpp.2012.164.173 2012/05/17 - 20:28

To study the response of okra (Abelmoschus esculentus cv. Marsaouia) to salinity, the effect on seedling growth, water content, anthocyanins content and chlorophyll fluorescence was investigated. Okra seeds were germinated in Petri dishes and sown in peat culture under controlled conditions and submitted during 2 weeks to saline stress ranging from 0 (distilled water) to 20, 40, 60, 80 and 100 mmol of NaCl. Results showed that salt has no significant effect on aerial part dry weight and it showed no changes in chlorophyll fluorescence parameters (Fo and Fv/Fm). By contrast, root dry weight decreased with increasing NaCl concentration with a subsequent increase in root water content and cotyledons+hypocotyls/root ratio. In addition, anthocyanins content and electrolyte leakage were highly increased by exposure to high levels of salt especially 80 and 100 mmol NaCl.

http://scialert.net/abstract/?doi=ajpp.2012.174.183 2012/05/17 - 20:28

The mangrove of Sundarbans eco-region lies in the delta formed by the rivers Ganges, Brahmaputra and Meghna, extends across the southern part of Bangladesh and West Bengal of India. Due elevated salinity (15-27 ppt) prevails in Indian Sundarbans that has detrimental impact on vegetation pattern leading to extinction of a few existing species like Heritiera fomes and Xylocarpus granatum. A comparative account of polymorphic expression of total leaf protein, two antioxidative enzymes (peroxidase and superoxide dismutase) and two hydrolyzing enzymes (Esterase and Acid phosphatase) were estimated both qualitatively and quantitatively from the leaves of five mangroves (viz., Bruguiera gymnorrhiza, Excoecaria agallocha, Heritiera fomes, Phoenix paludosa and Xylocarpus granatum, among which, H. fomes and X. granatum are considered as degraded and rest three are considered as natural control), from two different habitats (in situ habitat of Sundarbans and from ex situ habitat in fresh water condition) are discussed. The higher amount of total protein occurred in fresh water plants than that of their Sundarbans counterparts. The increment of total protein was ranged from 156 to 5.7%. Gel electrophoresis experiments revealed that in most of the cases there were extra numbers of protein bands expressed with relatively low molecular weight in saline habitat. A qualitative and quantitative study of four enzymes from both habitats revealed that in most of the cases, the numbers of isoforms, band intensity and enzyme concentrations were higher in saline habitat plants. PRX and SOD expressions were high in saline plants (ranged from 87-257% in the case of PRX and 83-229% in SOD). The increments were lower in Heritiera (87% in PRX, 83% in SOD) and Xylocarpus (98% in PRX, 76% in SOD) from saline habitat. EST increment was lower in Heritiera and Xylocarpus than other three taxa of saline habitat (137 and 143%, respectively, whereas other three species ranged from 169-287%). ACP increment in saline grown plants occurred ranging from 133-307%. Comparatively poor salt management ability in respect to protein degradation and antioxidative enzymes activity of Heritiera and Xylocarpus could be attributed with their gaunt existence in present day’s Sundarbans.

http://scialert.net/abstract/?doi=ajpp.2012.53.69 2012/03/12 - 10:45

This study was carried out at the National Center for Radiation Research and Technology during two successive seasons, of 2007/2008 and 2008/2009, respectively in pots 30 cm in diameter. The aim of this experiment was to study the response of damsisa (Ambrosia maritima L.) seeds that exposed to different doses of radiation (0, 20, 40, 80 Gy) after planting in soils contain mixtures of salts. The dose rate was 0.89 and 0.87 rad sec-1. The salts used were NaCl, CaCl2 and MgSO4 in ratio 2:2:1 with concentrations 2000, 4000 and 6000 ppm. Irradiated and un- irradiated seeds were sown in, sand-loamy, soil with mixture of salts. Also, a group of irradiated and un-irradiated seeds were sown in normal soils without salt and serve as a control, all pots irrigated with tap water until field capacity. It was observed that saline condition decreased ambrosin, protein and amino acids trend, in damsisa shoots. While, the results obtained refer to increasing proline concentration separated as a result of uses γ-rays and salinity treatments. The extreme sensitivity of the metabolic processes of proline synthesis and degradation themselves may be of benefit by regulating metabolic processes which adversely affected by stress. So, it was concluded that γ-rays improve plant growth and increase its chemical components under saline stress condition.

http://scialert.net/abstract/?doi=ajpp.2012.70.83 2012/03/12 - 10:45

A field experiment was conducted to determine the influence of magnesium (Mg), boron (B) and silicon (Si) availabilities on stomatal morphology, stomatal conductance and transpiration rate of Rastali. The experiment was done at Universiti Putra Malaysia under field condition arranged in split-split plot design with four blocks. The main factor was NPK fertilizer recommended by Department of Agriculture Malaysia (DOA) and United Plantation Berhad (UPB). The sub-factors were applications and non-application (as control) of kieserite (Mg), boric acid (B) and sodium silicate (Si). The sub-sub factors were the four Rastali accessions, namely, R08, R62, R34 and R12. In particular, the Berangan accession was selected as the control treatment. The observations were carried out on the stomatal morphology, stomatal conductance and transpiration rate. Data were analyzed with Analysis of Variance (ANOVA) at 5% level and continued with the Least Significant Differences (LSD) if significant. The relationship patterns among the parameters were determined using regression analysis. The findings showed that high-dose applications of NPK fertilizer enhanced stomatal length and width (abaxial and adaxial), stomatal conductance and transpiration rate, with or without Mg, B and Si. Similarly, in low doses, NPK fertilizers added with Mg, B and Si significantly enhanced stomatal length and width, stomatal conductance and transpiration rate. On the contrary, stomatal density (abaxial and adaxial) and ratio were not influenced by NPK fertilizer, Mg-B-Si or their combinations. Moreover, stomatal density and ratio were found to be different among the cultivars (Berangan and Rastali), but similar within the Rastali accessions. In particular, Berangan had a high stomatal density (abaxial and adaxial) compared Rastali, so stomatal ratio became smaller. There were linear relationships between stomatal width, stomatal conductance and transpiration rate, whereby wider stomata were shown to have resulted in higher conductance and transpiration rate.

http://scialert.net/abstract/?doi=ajpp.2012.84.96 2012/03/12 - 10:45

The use of different waste materials, Sewage Sludge (SS), Palm Fiber (PF) and Topsoil (TS) as substrates in the production vegetable plants were studied with a special interest on the suitability of palm fiber as growing substrate plants. It was composted during 60 days at equal volume (1:1) with SS. The five substrate mixtures were, T1 = 50% (SS and PF)+50% TS, T2 = 35% (SS and PF)+65% TS, T3 = 25% (SS and PF)+75% TS, T4 = 20% (SS and PF)+80% TS and T5 = 15% (SS and PF)+85% TS. The plant species tested were Lycopersicum esculentum and Cucumis melo. Electritical conductivity and pH substrate were periodically tested along the experiment. The mixture of T1 represented the most convenient substrate to use for L. esculentum regarding the other treatments. For C. melo, the mixtures of T1 and T2 gave the best relative performances. Therefore, it is important to consider the use of sewage sludge and palm fiber can influence positively the physico-chemical properties of horticultural substrate.

http://scialert.net/abstract/?doi=ajpp.2012.97.103 2012/03/12 - 10:45

Rooting and sprouting traits of single-node leafy cuttings (SNCs) of Grewia optiva have been studied in relation to age of donor plants and auxin treatments. SNCs from 1-, 5-, 10- and 15-year- old donors and treated IBA 3000 mg L-1 gave the best responses. Periodic sampling was performed to examine Total Soluble Sugar (TTS), Indole Acetic Acid (IAA) oxidase and peroxidase (PER) activities in the rooting zone during Adventitious Root Formation (ARF). TTS decreased with passage of time from 0 to 40 days of analysis. Auxin treatments exhibit higher TSS in all donors. IAA-oxidase and PER reduced with maturation. IAA-oxidase was highest in untreated cuttings while auxin treatments had enhanced PER activity. IAA-oxidase was found to decrease up to 20 days and increased thereafter. PER increased with time from the day of planting upto its 30 days, followed by a remarkable decline at 40, irrespective of age of donor plants or auxin treatments. Both enzyme activities remained higher in SNCs of 1-year-old donors which rooted more profusely as compared other donors. Present study suggests auxin treatments have activated carbohydrate metabolism to release energy for ARF. IAA-oxidase and PER activities seems to involve for triggering, initiation and elongation of root primordia.

http://scialert.net/abstract/?doi=ajpp.2012.1.16 2012/02/23 - 03:37

Rooting and sprouting traits of single-node leafy cuttings (SNCs) of Grewia optiva have been studied in relation to age of donor plants and auxin treatments. SNCs from 1-, 5-, 10- and 15-year- old donors and treated IBA 3000 mg L-1 gave the best responses. Periodic sampling was performed to examine Total Soluble Sugar (TTS), Indole Acetic Acid (IAA) oxidase and peroxidase (PER) activities in the rooting zone during Adventitious Root Formation (ARF). TTS decreased with passage of time from 0 to 40 days of analysis. Auxin treatments exhibit higher TSS in all donors. IAA-oxidase and PER reduced with maturation. IAA-oxidase was highest in untreated cuttings while auxin treatments had enhanced PER activity. IAA-oxidase was found to decrease up to 20 days and increased thereafter. PER increased with time from the day of planting upto its 30 days, followed by a remarkable decline at 40, irrespective of age of donor plants or auxin treatments. Both enzyme activities remained higher in SNCs of 1-year-old donors which rooted more profusely as compared other donors. Present study suggests auxin treatments have activated carbohydrate metabolism to release energy for ARF. IAA-oxidase and PER activities seems to involve for triggering, initiation and elongation of root primordia.

http://scialert.net/abstract/?doi=ajpp.2012.1.16 2012/02/23 - 03:37

Drought is one of the major abiotic stresses affecting the agricultural production worldwide. A generally drought tolerant legume, horsegram was chosen to compare and decipher the biochemical mechanisms of drought stress tolerance. For this, 25 day old plants of a drought tolerant (HPK 4) and a sensitive variety (HPKC 2) of horse-gram (Macrotyloma uniflorum L.) were subjected to drought stress (PEG; polyethylene glycol treatment) and control conditions (without PEG) for 48 h. Leaf and root tissues of these horsegram plants were harvested for biochemical and antioxidant enzymatic assays. The Relative Water Content (RWC), proline and phenol content were found to be significantly higher in the tolerant variety under drought stress. While the protein and Malondialdehyde (MDA) content was observed to be significantly higher in the sensitive variety under drought stress. Among the antioxidant enzymes, Peroxidase (POD), Superoxide Dismutase (SOD), Catalase (CAT) and Glutathione-s-transferase (GST) showed significant increase in the tolerant variety than the sensitive one under drought stress. However, Glutathione Reductase (GR) activity was observed to be decreased. The results suggested that higher levels of RWC, phenols and proline accumulation in tolerant variety of horsegram could play an important role in drought stress tolerance. The diverse levels of antioxidant enzymes may be responsible for the differential drought tolerance capacities of the two varieties.

http://scialert.net/abstract/?doi=ajpp.2012.17.29 2012/02/23 - 03:37

Drought is one of the major abiotic stresses affecting the agricultural production worldwide. A generally drought tolerant legume, horsegram was chosen to compare and decipher the biochemical mechanisms of drought stress tolerance. For this, 25 day old plants of a drought tolerant (HPK 4) and a sensitive variety (HPKC 2) of horse-gram (Macrotyloma uniflorum L.) were subjected to drought stress (PEG; polyethylene glycol treatment) and control conditions (without PEG) for 48 h. Leaf and root tissues of these horsegram plants were harvested for biochemical and antioxidant enzymatic assays. The Relative Water Content (RWC), proline and phenol content were found to be significantly higher in the tolerant variety under drought stress. While the protein and Malondialdehyde (MDA) content was observed to be significantly higher in the sensitive variety under drought stress. Among the antioxidant enzymes, Peroxidase (POD), Superoxide Dismutase (SOD), Catalase (CAT) and Glutathione-s-transferase (GST) showed significant increase in the tolerant variety than the sensitive one under drought stress. However, Glutathione Reductase (GR) activity was observed to be decreased. The results suggested that higher levels of RWC, phenols and proline accumulation in tolerant variety of horsegram could play an important role in drought stress tolerance. The diverse levels of antioxidant enzymes may be responsible for the differential drought tolerance capacities of the two varieties.

http://scialert.net/abstract/?doi=ajpp.2012.17.29 2012/02/23 - 03:37