Showing papers in "International Journal of Agriculture and Biology in 2015"

Plant growth promoting rhizobacteria: an alternate way to improve yield and quality of wheat (Triticum aestivum).

Abstract: In this research 198 isolates were collected from native soils of Pakistan and in vitro testing was done for Zn mobilizing activity. Three promising Zn solubilizers namely FA-2, FA-3, FA-4 and their consortium were tested under field conditions with four commercial wheat (Triticum aestivum L.) cultivars viz. Inqlab 91, Chakwal-50, Lasani-08 and SH-2002. A significant increase of 54, 68, 57 and 46% in wheat Zn content over chemical Zn fertilizer was observed under all PGPR treatments. Low increase in grain Zn concentration of 6.5, 7.0, 15.2 and 12.5% was noticed over control by Zn fertilizer treatment with all four wheat genotypes. Various wheat genotypes showed different response with PGPR applications. Similarly, all three strains and their consortium increased wheat grain yield by 2.4, 0.7, 2.2 and 8.6% over chemical Zn fertilizer, respectively. The strains identified by 16S rRNA, gyrB and gyrA gene analysis were Serratia liquefaciens, S. marcescens and Bacillus thuringiensis. The present findings show that enhanced rate of PGPR colonization can improve grain yield and Zn content of wheat as compared to chemical Zn fertilizer. Co-inoculation of PGPR proved to have more potential of Zn mobilization towards grain. Maintaining suitable density of Zn mobilizers in the soil through field inoculation might be a promising strategy to enhance grain yield and Zn content of wheat. Commercial field application of this approach among farmers is recommended. © 2015 Friends Science Publishers

Morpho-physiological studies, management and screening of tomato germplasm against Alternaria solani, the causal agent of tomato early blight.

Abstract: Early blight (Alternaria solani) is a potential disease of tomato that reduces its production globally both in conventional and tunnel cultivations. Due to variability in pathogenic isolates, prolonged active disease cycle phase and broad host range early blight is very difficult to manage. A. solani isolate collected from tunnel grown under vegetable area, Bahauddin Zakariya University, Multan was subjected to different temperature range, pH levels, light intensity and growth media (in vitro). The results indicated that A. solani grew the maximum at 25°C (7.50 cm) on PDA medium at 6.5 pH (8.34 cm) under continuous light condition (9.00 cm). On PDA medium the pigmentation varied from creamy yellow, brown black to olivacious brown while on HLEA medium it was light brown. Varietal screening of six tomato varieties was carried out against early blight disease. No variety was found resistant. Concerning severity, out of six tomato varieties Roma showed maximum susceptibility (70.50%) while in Nagina it was least (29.38%). Efficacy of three fungicides (Topsin M, Bavistin and Ridomil Gold MZ) at 1 g/L, 2 g/L and 3 g/L concentration and two bio-agents (Trichoderma harzianum and T. viridae) was evaluated against A. solani in vitro and under tunnel cultivation. In in vitro assay Ridomil Gold MZ inhibited A. solani (47.06%) at 2 g/L, while at 3 g/L concentration Topsin M was more effective (64.71%) as compared to control. Comparing both bioagents inhibition percentage (67.78%) was recorded in T. harzianum whereas T. viridae showed less inhibition (59.63%). Under tunnel cultivation, early blight of tomato was significantly reduced by foliar applications of Topsin M and T. harzianium at 3 g/L and 10 8 conidia/mL concentration, respectively comparing with untreated plants. In the light of present study farmers could be suggested the practice of resistance source, combination of management practices and avoidance of environmental conditions favoring the pathogen, thus result in significant production of tomato. © 2015 Friends Science Publishers

Hemato-biochemical and genetic damage caused by triazophos in fresh water fish, Labeo rohita.

Abstract: Extensive use of pesticides in agriculture sector represents a major proportion of pollutants and poses serious threats to both environment and aquatic organisms. In the present study micronucleus assay and nuclear abnormalities were used as a biomarker to assess the cyto-genotoxic potential of different concentrations of triazophos insecticide in fresh water fish (Labeo rohita L.). For this purpose 16 fresh water fish of same age and weight were kept into four equal groups (A-D) having four each. All the fish were kept in aquaria with 75 L water capacity for six days for acclimatization. Various sub-lethal concentrations of organophosphate insecticide triazophos (0.010, 0.015 and 0.200 ppm) were tested. For hematological and cyto-genotoxic studies blood samples were collected from each fish after 48, 72 and 96 h of post-treatment. Duplicate thin blood smear was made from fresh blood of each fish. Results revealed that total erythrocyte count, pack cell volume, hemoglobin concentration, serum total proteins, mean corpuscular hemoglobin concentration and mean corpuscular volume values were significantly (P<0.05) decreased, which indicated that fish were suffering from microcytic hypochromic anemia. Lymphocyte and monocyte values were also significantly decreased while leukocyte count was significantly increased. The results obtained by micronucleus assay showed significantly a higher frequency of erythrocyte with micronuclei, blebbed nuclei, lobed, notched, heteropicnotic nuclei, binucleated and pear shape erythrocyte. The serum analysis showed that the concentration of different enzymes and lipid peroxidation products were significantly increased in exposed fish. It can be concluded that triazophos poses adverse hemato-biochemical and DNA damage effects in aquatic organisms. © 2015 Friends Science Publishers

Molecular characterization of stress tolerant plant growth promoting rhizobacteria (PGPR) for growth enhancement of rice.

Abstract: The study was undertaken to characterize plant growth promoting rhizobacteria (PGPR) for growth enhancement and stress tolerant traits and their efficacy on early establishment of rice seedling. In vitro growth promoting traits revealed that out of 30 PGPR isolates, 18 fixed nitrogen, 17 solubilized tri-calcium phosphate, 29 and 17 produced IAA with or without addition of L-tryptophane. In case of stress tolerant activities, PGPR isolates tolerated pH ranging from 5 to 10, Nacl from 1 to 6% and polyethylene glycol (PEG) from 10 to 40%, respectively. They showed antagonistic activity against Pyricularia oryzae with PIRG values ranging from 7−68%. After two-stage of screening, isolates UPMR7 and UPMR17 were identified based on 16s rRNA gene sequences and matched to the genus Bacillus and Citrobacter with 97−98% similarity. UPMR 7 and UPMR 17 were further evaluated on early growth promotion of rice variety MR219. Results revealed that PGPR inoculation had significant effects on plant growth compared to non-inoculated plants. Thus, it could be suggested that the isolates UPMR7 and UPMR17 have the potential to be used as biofertilizer and bioenhancer in sustainable rice cultivation. © 2016 Friends Science Publishers

Super hybrid rice in China and India: current status and future prospects.

Abstract: Rice is a staple food for over half of the world's population and has the second largest cereal production after maize. Rice yield has experienced many fold jumps since the 1950s. This happened primarily as the result of genetic improvement and increasing harvest index by reducing plant height using the semi-dwarf genes and utilization of heterosis by producing hybrids. Hybrid rice technology is one of the strongest tools to break the yield barrier. To make hybrid rice technology practically feasible it needs strong system of hybrid seed production at commercial rate. Unlike maize, rice is a self-pollinated crop and needs special techniques, like utilization of male sterility system for hybrid seed production. The first hybrid rice variety for commercial cultivation was released by China in 1976. Seeing the China’s success many countries started the hybrid rice breeding programme. India also started this programme in 1989. In about two decades of efforts India released 65 hybrid rice varieties till 2013. Though, China is cultivating about 50% of its rice area under hybrid rice varieties, India is still struggling to enhance its acreage under hybrid rice from 4% to more. Because of complicated seed production system, higher seed cost and less preferred qualities of hybrid varieties it could not cover more area under cultivation in India. In 1998, China started work for developing super hybrid rice by combining an ideotype approach with the use of inter-sub specific heterosis. Till 2011, the Ministry of Agriculture, China approved 56 hybrid cultivars with great yield potential as super hybrid rice. Hence, India and China still have to work hard for developing high yielding super hybrids coupled with good cooking qualities and resistance/tolerance to major biotic and abiotic stresses. Suitable technology should also be developed to make hybrid seed production easier and cheaper. © 2015 Friends Science Publishers

Toxicity to hematology and morphology of liver, brain and gills during acute exposure of Mahseer (Tor putitora) to cypermethrin.

Abstract: The present study was aimed to evaluate the effects of acute dose of Cypermethrin (CYP), an extensively use synthetic pyrethroid, on hematology and morphology of the liver, gills and brain of Mahseer (Tor putitora). The effects were assessed on the basis of the previous results of acute toxicity test after exposing fish to acute concentration, 63 μg L -1 (LC50 of 96 h) of CYP. Light microscopic studies revealed severe histopathological changes in liver, gills and brain tissues. The morphological alterations in liver involved glycogen vacuolation, hemorrhage vacuolation, congestion, fatty infiltration and hepatic necrosis. In gills, it resulted in cellular infiltration, congestion, swollen tip of the gill filament, hetrophilic infiltration and damaged gill while in the brain it caused discoloration, neuronal degeneration, infiltration and severe spongiosis. Blood cell count also showed the toxic effect of CYP, as RBCs count decreased while WBCs count increased with time in the treated group. The results clearly classify CYP as a strong toxic agent for T. putitora. © 2015 Friends Science Publishers

Plant-nematode interactions: from genomics to metabolomics.

Abstract: Plant parasitic nematodes are obligate parasites causing serious reduction in crop yields. Several economically important species parasitize various plant species, but the root knot and cyst nematodes belonging to the Heteroderidae family are especially dangerous. Plant parasitic nematodes result in crop losses of over $150 billion worldwide. This review gives an account of morpho-physiological and molecular events during parasitism of root-knot and cyst nematodes. It describes the transcriptomes and parasitomes of various nematodes indicating that the effector proteins are crucial for the compatible plant nematode interactions. Various sequencing techniques used in plant-nematode genomics and transcriptomics are discussed. Moreover, the dynamics of host transcriptomes in response to infection with different nematode species have been reported. The host transcriptomes have unrevealed many candidate genes, which are involved in both compatible and incompatible plant nematode interactions. The strategy of manipulation of expression of the genes induced and suppressed by the nematodes in the feeding sites has also been suggested for enhancement of resistance against nematodes. This review will provide the researchers with the information regarding transcriptional changes in the nematodes as well as host plants, which would be important for the induction of resistance against nematodes in different crop plants. © 2015 Friends Science Publishers

Status of insecticide resistance in field-collected populations of Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae).

Abstract: The first monitoring of the resistance to two organophosphates (methidathion and ethion) and one pyrethroid (cypermethrin) insecticides presented by three field collections of different Rhynchophorus ferrugineus (Olivier) populations was performed in this study. The LD50 doses of three insecticides against newly moulted eighth-instar R. ferrugineus larvae were estimated through toxicity bioassays, in which the larvae were fed on artificial diet supplemented with different individual doses of cypermethrin, methidathion or ethion. A population of R. ferrugineus collected from Wadi Ad-Dawasir was chosen as the reference strain, because of its susceptibility to each of the tested insecticide. Compared with the susceptible strain, populations sampled from Al-Ahsa and Al-Qatif showed 8.72 and 4.51-folds increase in resistance to cypermethrin and 3.77 and 2.85-fold increases in resistance to ethion, respectively. The LD50 values of cypermethrin (1.62 ppm), methidathion (3.15 ppm) and ethion (9.12 ppm) in the susceptible population (Wadi Ad-Dawasir) were used to investigate the feeding performances and physiological impacts on eighth-instar R. ferrugineus larvae. The larvae showed no resistance to the most potent insecticide (methidathion) resulting highest growth reduction. However, moderate resistance was observed from red palm weevil population collected from Al-Qatif and Al-Ahsa against cypermethrin resulting lowest reduction in the efficacy of conversion of ingested food (ECI) and digested food (ECD). In addition, glutathione-S-transferase (GST) activity assay further strengthen our findings. Results suggest that enhanced GST activity likely contributes to cypermethrin and ethion resistance exhibited by the R. ferrugineus populations sampled from Al-Qatif and Al-Ahsa. Toxicity bioassays, dietary utilization experiments and GST assays examined in this study support the use of methidathion against R. ferrugineus as the most potent insecticide against all the sampled populations. However, cypermethrin and ethion resistance appears to be evolving in the R. ferrugineus populations from Al-Qatif and Al-Ahsa, justifying the concern of farmers regarding the low efficacy of insecticides. © 2016 Friends Science Publishers

Essential oil compositions and cytotoxicity from various organs of Eucalyptus camaldulensis.

Abstract: In the present study essential oil compositions from leaves, stems and immature flowers of Eucalyptus camaldulensis Dehnh. from Malaysia and their cytotoxicity effects were investigated. The essential oils were obtained by hydrodistillation and the composition was determined by gas chromatography-mass spectrometry (GC-MS). The cytotoxicity of the essential oils was evaluated by MTT assay. The oil yields of leaves, stems and immature flowers of the plant represented 1.40, 0.57 and 0.46 %, respectively, based on dry weight. Fifteen major compounds were identified represented 98.8, 97.5 and 99.5% of the compounds in the leaves, stems and immature flowers, respectively. Monoterpenes hydrocarbons were predominant in the three oil samples. The flower oil was the highest in oxygenated monoterpenes content (19.6%). The most abundant compounds in the three essential oils were γ-terpinene, as a principal oil component (57.4–72.5%) followed by o-cymene (14.6–26.3%) and terpinen-4-ol (6.6–16.2%). E. camaldulensis leaves essential oil demonstrated cytotoxic effects in three tested cancer cell lines; WEHI-3, HT-29 and HL-60. WEHI-3 was the most sensitive with IC50 16.1. The essential oil exhibited less cytotoxic effects in HT-29 and HL-60 cells (IC50=50.5 and 42.1, respectively). Also, it exhibited a weak cytotoxic effect in RAW 264.7 cells. The main component of the oil, γ-terpinene also, showed a very weak cytotoxic effect in the tested cell lines without reaching IC50 values within the studied concentration ranges. These findings add significant information to the pharmacological effects of E. camaldulensis essential oil and to its cytotoxic properties, thus justifying and reinforcing the pharmaceutical use of this plant oil. © 2015 Friends Science Publishers

Biofertilizers in Pakistan: Initiatives and Limitations

Abstract: Biological preparation containing live or latent cells of microorganisms or their metabolites, which when inoculated to seed, soil or roots of seedlings, promote plant growth and enhance harvestable yield is termed as biofertilizer. Biofertilizers, generally marketed, contain microbes capable of nitrogen (N) -fixation, phosphate solubilization/mineralization, phytohormone production and biocontrol. This paper reviews various initiatives in research and development of the biofertilizers taken by different institutes of Pakistan. The use of biofertilizers can play an important role in sustaining the agriculture systems. In Pakistan, where fertilizer is annually a hundred billion rupees business, even a 10% contribution by biofertilizer can save rupees ~10 billion. Various research groups/organizations are engaged in research and development on biofertilizers and have made their efforts to increase the application of biofertilizers in Pakistan’s agriculture. Inconsistent field performance, lack of regulation and standards, quality issues of the product(s), awareness and lack of publicity are the major constraints in the widespread use of biofertilizers in Pakistan. If these problems are resolved, better results and responses can be expected through biofertilizer use in Pakistan. Assuring quality of products with extensive field-based testing, capacity building of resource persons and stakeholders on standard production processes, storage and application will help a wider adoption and popularization of the biofertilizer technologies. © 2015 Friends Science Publishers

Auxin producing plant growth promoting rhizobacteria improve growth, physiology and yield of maize under saline field conditions.

Abstract: Soil salinity is one of the most widespread agricultural problems which reduce the field crop productivity. Salinity disturbs the hormonal balance in plants which results in poor growth. Use of plant growth promoting rhizobacteria (PGPR) is considered an economical and environment-friendly approach to combat salinity stress. This study was carried out to investigate the effect of auxin producing PGPR on the growth, antioxidant status and mineral content of maize (Zea mays) in salt affected soils. Rhizobacterial strains were isolated from the rhizosphere of maize growing under salt affected soil conditions. These strains were screened on the basis of auxin production and their ability to withstand salinity stress. Two stains (MA4 and MA11) which produced highest auxin and tolerated maximum salinity were selected for further evaluation in a field experiment. The results of field trial showed that soil salinity reduced the plant growth, mineral nutrient uptake and yield of maize while antioxidant activity and proline concentration was increased. However, rhizobacterial inoculation improved grain yield (31%), fresh biomass (56%) and phosphorous contents in grains (26%) while the proline concentration (41%), ascorbate peroxidase (59%) and SOD values (42%) in leaves were declined. The results of present study signify the role of auxin producing rhizobacteria under salt affected field conditions. © 2015 Friends Science Publishers

Comparative nutritional profiles of various faba bean and chickpea genotypes.

Abstract: Grain legumes are important source of proteins and dietary minerals for humans. In this study, 40 faba bean and 28 chickpea genotypes were evaluated for their nutritional profile. We found that crude proteins ranged from 31.5-37.7% and 19.8-24.9% in faba bean and chickpea genotypes, respectively. Trypsin and chymotrypsin inhibitors varied from 2.24-2.77 and 0.35-0.70 trypsin inhibitory unit (TIU) mg -1 , respectively in faba bean genotypes; whereas, in chickpea genotypes, they ranged from 7.65-8.98 and 9.0-11.9 TIU mg -1 , respectively. Tannins in faba bean ranged from 12.2-16.2 mg 100 g -1 , while in chickpea they ranged from 4.11-4.94 mg g -1 . However, phytic acid ranged from 1.2-1.5 mg 100 g -1 in faba bean, while in chickpea it ranged from 6.10-6.98 mg g -1 . Total phenolic and total flavonoid contents ranged from 5.8-11.3 mg galic acid equivalents (GAE) g -1 and 0.08-0.16 mg quercetin equivalent (QE) g -1 , respectively in faba bean genotypes; whereas, in chickpea genotypes, these ranged from 1.5-2.5 mg GAE g -1 and 0.05-0.18 mg QE g -1 , respectively. In crux, some faba bean and chickpea genotypes could be potential donors for legume genetic improvement and incorporation of such legumes in human diets may improve the nutritional value of diet and can reduce malnutrition. © 2015 Friends Science Publishers

Nutritional evaluation of fresh and wilted mixed silage of naked oats (Avena nuda) and alfalfa (Medicago sativa).

Abstract: Nutritional evaluation of fresh and wilted silage made of Naked Oats (Avena nuda L.) and Alfalfa (Medicago sativa L.) in different proportions (0:1, 1:0, 1:1, 2:1 and 1:2) was carried out in present study. The changes between fermentation quality and nutrition composition were observed after 60 days. The results based on sensory evaluation showed that the wilted silage was better than fresh silage, and the quality of silage improved gradually with the increase of the proportion of naked oats. The pH value and the content of propionic acid (PA) of wilted silages had no significant difference (P>0.05), and following the increased ratio of naked oats, the pH value and the content of PA of mixed silages were significantly decreased (P<0.01). Wilted and the increased ratio of naked oats significantly increased the content of lactate (LA) (P<0.01), and reduced the content of butyrate acid (BA) and ammoniacal nitrogen/total nitrogen (NH3-N/TN) (P<0.01). The most significant nutritional effect (decrease or increase) was observed when naked oats and alfalfa were mixed in 2:1 ratio. The content of dry-matter (DM) and water-soluble carbohydrate (WSC) had significant change (P<0.01) and the content of crude ash (Ash) also had significant change (P<0.05), and other nutrient contents had no significant change (P>0.05) in wilted treatments. With the increase of alfalfa in mixed silage, the content of crude protein (CP) was significantly increased (P<0.01) and the content of WSC and neutral detergent fiber (NDF) were decreased (P<0.05), and other nutrient contents had no significant change (P>0.05). The interaction of wilted and mixed ratio showed significant effect on pH value (P<0.05), the content of LA (P<0.01), PA (P<0.05) and BA (P<0.01), and had no significant effect on the contents of AA and NH3-N/TN (P>0.05). Sensory evaluation revealed that fermentation quality and nutritional composition of mixed silages of naked oats and alfalfa were better than alone, and the quality of wilted silages was better than fresh silages. © 2015 Friends Science Publishers

Alleviating effect of exogenous application of ascorbic acid on growth and mineral nutrients in cadmium stressed barley (Hordeum vulgare) seedlings.

Abstract: An experiment was carried out in sand-filled pots under normal temperature (28±2oC) to assess the role of exogenously applied ascorbic acid in alleviating the effect of cadmium (Cd) stress on four barley (Hordeum vulgare L.) genotypes (Jau-83, Jau-87, Paidar 91 and Haider 93). After germination, seedlings were exposed to different Cd concentrations (0, 100, 300, 500 and 700 μM CdCl2) along with AsA (200 mg L) and grown for 15 days. The results suggested that exposure to increased Cd levels caused a significant reduction in growth and mineral nutrients contents of barley seedlings. However, there was a noticeable difference in the effect of Cd on mineral concentrations among genotypes and the difference mainly coincided with differential accumulation of Cd in the shoot and root tissues. When AsA was applied to Cd-stressed plants, it decreased Cd accumulation in shoots and roots and also showed partial reversal of Cd stress effects. It was also observed that at the same Cd concentrations Cd tolerance index of Jau-83 was the highest among the four barley genotypes, indicating that Jau-83 had lower Cd contents in roots may be more tolerant to Cd stress. The application of AsA was effective in reducing the toxicity of increased Cd by reducing the root or shoots Cd contents, as well as by improving the seedling growth attributes and the mineral nutrients in barley. © 2016 Friends Science Publishers

Physiological responses of alfalfa to high-level salt stress: root ion flux and stomatal characteristics.

Abstract: Alfalfa is an important salt-tolerant leguminous forage-plant in salinity areas worldwide, but its performance in high level of salt stress cannot meet the satisfactory requirement. Especially, the short-term response of alfalfa to high-level salt stress is still not clear. In the present study, thirty-day-old alfalfa Gongnong No. 1 (Medicago sativa L. cv. Gongnong No.1) seedlings were exposed to NaCl treatments at concentrations of 0 (control), 50 (moderate level), 150 (high level), and 250 mM (extremely high level). Twenty-four hours after salt stress treatment, with the increase of NaCl level plant height was slightly decreased but both shoot biomass and root length were substantially declined to a dramatic extent. Also decreased was root K concentration. In contrast, both Na concentration and ratio of K/Na showed increased trends. Root K flux was determined using non-invasive micro-test technique (NMT) around apical root tips, wherein a clear K influx was observed at the rate of about 0.5 nmol cm s under the condition without salt stress, while under salt stress at the rate of 2‒3 nmol cm s did occur K efflux. Accordingly, stomatal length and breadth and stomatal aperture breadth decreased with the increase of NaCl concentration, while stomatal aperture density increased with time in the first 24 h after NaCl treatment. In conclusion, as a species-specific test, alfalfa is sensitive to high-level salinity with NaCl concentrations above 150 mM in the first 24 h post salt-exposure. The key mechanism was found to be presented as the pressed stamatal conductance induced by K-Na unbalance which was caused by root K efflux. © 2016 Friends Science Publishers

Mitigating Ammonia Volatilization from Urea in Waterlogged Condition Using Clinoptilolite Zeolite

Abstract: Besides causing environmental pollution, ammonia volatilization from nitrogenous fertilizers such as urea reduce urea-N use efficiency in agriculture. Amending urea with Clinoptilolite zeolite may reduce ammonia loss from urea as well as improving chemical properties of soils. This study was conducted to determine the effects of amending an acid soil with Clinoptilolite zeolite on ammonia loss and selected soil chemical properties. An acid soil (Typic Paleudults) was mixed with three rates of Clinoptilolite zeolite. Treatments were evaluated using closed-dynamic airflow system. Standard procedures were used to determine soil pH, total nitrogen, exchangeable ammonium, available nitrate, available phosphorus, exchangeable cations, organic matter, total organic carbon, and cation exchange capacity (CEC). Application of Clinoptilolite zeolite significantly reduced ammonia loss up to 25.33%, increased soil pH, exchangeable ammonium, available nitrate (treatment with highest amount of Clinoptilolite zeolite) and exchangeable cations. However, there was reduction in total titratable acidity, exchangeable Al 3+ and H + ions. Mixing acid soil (Typic Paleudults) with Clinoptilolite zeolite minimized ammonia loss from urea and improved selected soil chemical properties (under laboratory condition). © 2015 Friends Science Publishers