Impact of Climate Change on Dryland Agricultural Systems: A Review of Current Status, Potentials, and Further Work Need.

Dryland agricultural system is under threat due to climate extremes and unsustainable management. Understanding of climate change impact is important to design adaptation options for dry land agricultural systems. Thus, the present review was conducted with the objectives to identify gaps and suggest technology-based intervention that can support dry land farming under changing climate. Careful management of the available agricultural resources in the region is a current need, as it will play crucial role in the coming decades to ensure food security, reduce poverty, hunger, and malnutrition. Technology based regional collaborative interventions among Universities, Institutions, Growers, Companies etc. for water conservation, supplemental irrigation, foliar sprays, integrated nutrient management, resilient crops-based cropping systems, artificial intelligence, and precision agriculture (modeling and remote sensing) are needed to support agriculture of the region. Different process-based models have been used in different regions around the world to quantify the impacts of climate change at field, regional, and national scales to design management options for dryland cropping systems. Modeling include water and nutrient management, ideotype designing, modification in tillage practices, application of cover crops, insect, and disease management. However, diversification in the mixed and integrated crop and livestock farming system is needed to have profitable, sustainable business. The main focus in this work is to recommend different agro-adaptation measures to be part of policies for sustainable agricultural production systems in future.

Toxicity of NiO nanoparticles to soil nutrient availability and herbage N uptake from poultry manure.

Recently, there is an increasing trend of using metallic nanoparticles (NPs) in agriculture due to their potential role in remediating soil pollution and improving nutrient utilization from fertilizers. However, evidence suggested that these NPs were toxic to the soil life and their associated functions, and this toxicity depended on their dose, type, and size. Here, a dose-dependent (5, 50, and 100 mg kg-1 soil) toxicity of NiO NPs on poultry manure (PM: 136 kg N ha-1) decomposition, nutrient mineralization, and herbage N uptake were studied in a standard pot experiment. The NPs doses were mixed with PM and applied in soil-filled pots where then ryegrass was sown. Results revealed that the lowest dose significantly increased microbial biomass (C and N) and respiration from PM, whereas a high dose reduced these parameters. This decrease in such parameters by the highest NPs dose resulted in 13 and 41% lower soil mineral N and plant available K from PM, respectively. Moreover, such effects resulted in 32 and 35% lower herbage shoot and root N uptakes from PM in this treatment. Both intermediate and high doses decreased herbage shoot Ni uptake from PM by 33 and 34%, respectively. However, all NPs doses did not influence soil Ni content from PM. Hence, our results indicated that high NPs dose (100 mg kg-1) was toxic to decomposition, nutrient mineralization, and herbage N uptake from PM. Therefore, such NiONPs toxicity should be considered before recommending their use in agriculture for soil remediation or optimizing nutrient use efficiency of fertilizers.

Desert Soil Microbes as a Mineral Nutrient Acquisition Tool for Chickpea (Cicer arietinum L.) Productivity at Different Moisture Regimes.

Drought is a major constraint in drylands for crop production. Plant associated microbes can help plants in acquisition of soil nutrients to enhance productivity in stressful conditions. The current study was designed to illuminate the effectiveness of desert rhizobacterial strains on growth and net-return of chickpeas grown in pots by using sandy loam soil of Thal Pakistan desert. A total of 125 rhizobacterial strains were isolated, out of which 72 strains were inoculated with chickpeas in the growth chamber for 75 days to screen most efficient isolates. Amongst all, six bacterial strains (two rhizobia and four plant growth promoting rhizobacterial strains) significantly enhanced nodulation and shoot-root length as compared to other treatments. These promising strains were morphologically and biochemically characterized and identified through 16sRNA sequencing. Then, eight consortia of the identified isolates were formulated to evaluate the growth and development of chickpea at three moisture levels (55%, 75% and 95% of field capacity) in a glass house experiment. The trend for best performing consortia in terms of growth and development of chickpea remained T2 at moisture level 1 > T7 at moisture level 2 > T4 at moisture level 3. The present study indicates the vital role of co-inoculated bacterial strains in growth enhancement of chickpea under low moisture availability. It is concluded from the results that the consortium T2 (Mesorhizobium ciceri RZ-11 + Bacillus subtilis RP-01 + Bacillus mojavensis RS-14) can perform best in drought conditions (55% field capacity) and T4 (Mesorhizobium ciceri RZ-11 + Enterobacter Cloacae RP-08 + Providencia vermicola RS-15) can be adopted in irrigated areas (95% field capacity) for maximum productivity of chickpea.

Foliar epidermal anatomy of Lamiaceae with special emphasis on their trichomes diversity using scanning electron microscopy.

Foliar epidermal features were based on the micromorphology of trichomes types, epidermal cells and stomatal complex. Even though each feature has its own limited taxonomic value but collectively these characteristics may be systematically important especially for the discrimination and identification of complex and problematic taxa. The systematics significance of nonglandular (NGTs) and glandular trichomes (GTs), stomatal complex and epidermal cells of Lamiaceous flora were analyzed by using the light microscopy (LM) and scanning electron microscopy (SEM). Variations on the observed epidermal appendages were divided into two basic types: glandular and nonglandular. GTs can be divided into subtypes: sessile capitate, subsessile capitate, and barrel and sunken. NGTs were also divided into subtypes: dendritic, stellate, conical, falcate, simple and 1-6 cells long having granulate and smooth surface ornamentation. NGTs were the most dominant features of both adaxial and abaxial surfaces of all observed taxa. Vitex negundo, Isodon rugosus, Colebrookea oppositifolia, and Marrubium vulgare could be demarked because of their twisted like appearance of NGTs at the abaxial surface. The Lamiaceae had both hypostomatic and amphistomatic leaf. Stomata were observed as diacytic, anisocytic, and anomocytic. Epidermal cells were found to be irregular, isodiametric, and rectangular. Based on these characters a taxonomic key was developed to delimit the closely related taxa. Distribution and morphology of the foliar epidermal trichomes through SEM highlight an important taxonomic tool used by the taxonomists as an aid to the correct identification of problematic Lamiaceae taxa.

Determination of lytic enzyme activities of indigenous Trichoderma isolates from Pakistan.

This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, ß-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. ß-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract.

Determination of lytic enzyme activities of indigenous Trichoderma isolates from Pakistan

Abstract This study investigated lytic enzyme activities in three indigenous Trichoderma strains namely, Trichoderma asperellum, Trichoderma harzianum and Trichoderma sp. Native Trichoderma strains and a virulent strain of Rhizoctonia solani isolated from infected bean plants were also included in the study. Enzyme activities were determined by measuring sugar reduction by dinitrosalicylic acid (DNS) method using suitable substrates. The antagonists were cultured in minimal salt medium with the following modifications: medium A (1 g of glucose), medium B (0.5 g of glucose + 0.5 g of deactivated R. solani mycelia), medium C (1.0 g of deactivated respective antagonist mycelium) and medium D (1 g of deactivated R. solani mycelia). T asperellum showed presence of higher amounts of chitinases, β-1, 3-glucanases and xylanases in extracellular protein extracts from medium D as compared to medium A. While, the higher activities of glucosidases and endoglucanses were shown in medium D extracts by T. harzianum. β-glucosidase activities were lower compared with other enzymes; however, activities of the extracts of medium D were significantly different. T. asperellum exhibited maximum inhibition (97.7%). On the other hand, Trichoderma sp. did not show any effect on mycelia growth of R. solani on crude extract.

Ruptured hydatid cyst in biliary tract.

A lady aged 26 years reported with a 2 months history of fever, upper abdominal pain and weight loss. Her abdominal ultrasonographic scan revealed a complex cystic mass in left lobe of liver suggestive of hydatid cyst that was confirmed on magnetic resonance imaging of abdomen and magnetic resonance cholangiopancreatogram. With strong suspicion of a hydatid cyst, endoscopic retrograde cholangiogram was performed which confirmed the diagnosis. During the procedure, hydatid membranes protruding from the papilla were removed after sphincterotomy. She was put on albendazole 400 mg twice daily after the procedure and showed a remarkable clinical improvement.

Endoscopic findings and treatment outcome in cases presenting with dysphagia.

BACKGROUND: Dysphagia results from impeded transport of liquids, solids, or both from the pharynx to the stomach. Among the malignant lesions, carcinoma of oesophagus is the commonest cause. Our objective was to find out the frequency of different endoscopic lesions and outcome of the endoscopic therapeutic interventions in patients presenting with dysphagia. METHODS: This descriptive study was conducted at Department of Gastroenterology, Military Hospital Rawalpindi from June 2008 to May 2009. Patients of dysphagia after their consent were interviewed about the symptoms. Relevant biochemical investigations were done. Barium swallow and upper Gastrointestinal (GI) Endoscopy were carried out. Benign strictures were dilated with Savary Gilliard Dilators. Malignant strictures were further evaluated to decide treatment plan. In patients considered to have oesophageal dysmotility, pressure manometery was done before specific therapy. RESULTS: Seventy nine patients were enrolled. Twenty-five had malignant strictures, out of those commonest was adenocarcinoma 14 (56%). Twenty-nine had benign strictures the commonest being Gastro-oesophageal Reflux Disease (GERD) related peptic stricture 9 (31%). Fifteen had oesophageal dysmotility, and achalasia was present in 10 out of them. After evaluation 12 out of 25 patients with malignant strictures were considered fit for surgery. Self-expanding metal stents (SEMS) were passed in 5. All benign strictures were dilated with Savary-Gillard dilators. Pneumatic balloon dilation was done in patients of achalasia. CONCLUSION: The commonest malignant lesion resulting in dysphagia was adenocarcinoma while in benign it was GERD related peptic stricture. Achalasia was most frequent in oesophageal motility disorders. Standard of treatment for early oesophageal malignancy is surgical resection. SEMS is a reliable way to allay dysphagia in inoperable cases. Savary Gillard dilatation in benign, and pneumatic balloon achalasia dilatations are effective ways of treatment.

Indications for endoscopic ultrasound and diagnosis on fine-needle aspiration and cytology.

OBJECTIVE: To determine common indications for requesting Endoscopic Ultrasound (EUS) and to describe the diagnosis made after endoscopic ultrasound/Fine-Needle Aspiration and Cytology (FNAC) during two years at a tertiary gastrointestinal unit. STUDY DESIGN: Cross-sectional descriptive study. PLACE AND DURATION OF STUDY: The study was carried out in Gastrointestinal Department of Military Hospital, Rawalpindi, from March 2006 to February 2008. METHODOLOGY: One hundred and eighty nine patients who underwent EUS during study period at Military Hospital were included in the study. Patients too ill (hypoxemic/hypotensive) to undergo procedure safely and those with complete esophageal blockage at upper end by tumour not allowing scope/EUS probe to advance beyond were excluded. EUS was done with Olympus Exera EUS 160, linear or radial scope, as required. EUS findings were recorded against indications as enlarged lymph nodes, tumour, staging, normal or incomplete. Fine-Needle Aspiration (FNA) was done as per findings on EUS using 21-22 G needle. An on-site cytopathologist made the provisional cytopathological diagnosis. Final cytology/histopathology report was given after review of slides by consultant histopathologists at Armed Forces Institute of Pathology (AFIP), Rawalpindi, and were documented as tuberculosis, malignancy, chronic pancreatitis or reactive hyperplasia. Data was analyzed for documentation of patients' age, gender, common indications, findings on EUS/FNAC, using SPSS version 10. Percentages and frequencies were calculated for the presence of these above-mentioned variables. RESULTS: Of the 189 patients, 145 (77%) were male and 44 (23%) female. Age was 18-80 years (mean 49 years). Major indications for referral were lymphadenopathy in 92 (49%), suspected growth pancreas in 57 (28%), growth of stomach in 20 (11%) and a heterogeneous group included esophageal, liver, retroperitoneal masses, rectal and other pathologies. Findings on EUS included lymphadenopathy in 76, mostly in sub-carina and AP window. Mass in pancreas was seen in 36, followed by stomach tumour in 17 and esophagus in 9. FNAC was done in 142 out of 189 patients. Final diagnosis out of 67 FNAC/histopathology of lymph nodes were tuberculosis in 26 and malignant lesions in 23. These included metastatic adenocarcinoma in 8, lymphoproliferative disorder in 7, metastatic squamous cell carcinoma in 5, small cell carcinoma in 2 and anaplastic in 1. Pancreatic tumours were adenocarcinoma in 16, poorly differentiated in 3 and neuroendocrine in 2. Stomach tumours were found in 11, and included lymphomas 5, GIST 3, carcinoids 2, metastatic choriocarcinoma 1 and adenocarcinoma in 1. Therapeutically, 3 celiac blocks and one pancreatic pseudocyst drainage was done. CONCLUSION: The main indication of EUS and pathology of mediastinal and celiac nodes were metastatic malignancy and tuberculosis. Pancreatic adenocarcinoma was another common cause for asking EUS.

Diagnostic evaluation of patients presenting with bleeding per rectum by colonoscopy.

BACKGROUND: Rectal bleeding is a manifestation of lower gastrointestinal bleed, which means bleeding from a site distal to ligament of Treitz. Annual incidence of this problem has been estimated to be 20% and mortality as 11%. Patients complaining of haematochezia are suspected of having lower GI bleeding and proctosigmoidoscopy followed by colonoscopy is the examination of choice for diagnosis and treatment. Previous evidence suggested that in our country, frequencies of different aetiologies of lower GI bleed are different from the West. This study validated the previous findings. The Objective of this study was to determine the causes of rectal bleeding in adult patients at Military Hospital, Rawalpindi. METHODS: One hundred and five adult patients with visible rectal bleed, irrespective of their gender were selected by non-probability convenient sampling from general medical OPD and general medical wards. Patients with suspected upper GI source of bleeding; haemorrhoidal bleed and acute infectious diarrhoea were excluded from the study. All patients were subjected to fibre-optic colonoscopy after necessary preparation and findings were recorded. Biopsies taken from suspected lesions were clinically indicated. Diagnosis was based on colonoscopic and histopathologic findings. RESULTS: A total of 105 patients (77 male and 28 female) with mean age 41.04 yrs were part of the study. Colonoscopy showed abnormal findings in 85 (84%) patients. The commonest diagnosis was ulcerative colitis, which was found in 48 (46%) patients. It was followed by colorectal carcinoma, 11 (10%) patients, and non-specific colitis, 9 (8%) patients. Other less frequent findings were colonic diverticuli, 7 (6%) patients, solitary rectal ulcer, 5 (4%) patients, colonic polyps in 3 (2.5%) patients and one case each of telangiectasia and Crohn's disease. CONCLUSION: Colonoscopy has very high diagnostic yield and would be recommended in the workup of patients presenting with bleeding per rectum. Ulcerative colitis was the leading cause of bleeding per rectum in this study; while infrequent findings of Crohn's disease, polyps and diverticuli indicate that these are uncommon in this region.