Influence of Seedling Age and Nitrogen Rates on Productivity of Rice (<i>Oryza sativa</i>L.): A Review

Rice is an important crop and the food security of the world is strongly associated with it as it is the staple food of half of the world’s population. Among various agro-management practices seedling age and nitrogen rates significantly affected its growth, development and yield components. Rice cultivars performed differently when transplanted in field at varying seedling ages depending upon their genetic makeup and adoptability to certain environmental conditions. Seedling age plays an important role in yield contributing parameters like number of productive tillers, panicle length, filled grains panicle-1 and 1000-kernel weight leading to higher paddy yield in different rice cultivars and hybrids. Nitrogen is required in huge quantity in rice production as it is an important constituent of plant parts and processes. Paddy yield increases significantly with the increase in nitrogen rate but after a certain limit yield starts decreasing. Keeping in view the significance of seedling age and nitrogen rates in different rice cultivars and hybrids, an effort has been made to review some research work already conducted and will be helpful to the researchers and scientists to plan future strategies.

Enhancing the Salt Tolerance Potential of Watermelon (<i>Citrullus lanatus</i>) by Exogenous Application of Salicylic Acid

Salicylic acid (SA) is a vital plant growth regulator providing promising role in plant development and adopts defense mechanism to abiotic stresses. Salinity is the most limiting abiotic factor for plant development and growth changes in watermelon by producing reactive oxygen species and ultimately oxidative stress. The present study was aimed to investigate the mechanism involved in salt stress alleviation in watermelon (Citrullus lanatus Thanb. Mavs.) through the foliar application of salicylic acid. Watermelon cv. Charleston Gray was grown under moderate saline regime of 3 ds·m-1 NaCl and sprayed with salicylic acid with four level (0.5, 1.0, 2.5 and 5.0 mmol/L) compared along with control. SA @ 5.0 mmol/L was found to be very effective in mitigation of salt stress. SA was found to be very effective in alleviation of salinity stress by produced antioxidants and acted as osmo-regulator.

Evaluation of Different Radish (Raphanus sativus) Genotypes under Different Saline Regimes

An effective and simple screening technique for identification of salt tolerant and salt sensitive radish genotypes was observed. Sand is used as potting media. Six genotypes of radish were used for screening against four salinity levels (0, 1, 3, 5 and 7 dS/m-1). Twenty days old seedlings of radish were salinized with salt solution (NaCl). Morphological, physiological and ionic parameters were studied. Radish genotypes Laal-Pari and 40 Days executed the best performance in all the measured attributes and categorized as salt tolerant genotype while Green Neck was the poorest in retaining normal functioning at higher salinity levels thus grouped under salt sensitive cultivar.

Influence of Additives on Enhanced in Vitro Shoot Multiplication of <i>Stevia rebaudiana</i>(Bert.)—An Important Anti Diabetic Medicinal Plant

The present study was designed to develop an efficient protocol for micro propagation of S. rebaudiana from nodal explants and study the influence of additives on enhancement of shoot proliferation. A two-step protocol has been standardized in which, first step comprising growth hormones concentration is optimized and it was found that MS medium supplemented with 2.0 mg/l BAP + 0.5 mg/l Kin + 0.1 mg/l NAA turned out to be the best treatment for shoot induction. In the second step, the best treatment for shoot induction was fortified with different growth additives for further shoot proliferation. Among the different types of additives used, casein hydrolysate at 0.05% (w/v) was found to be most effective, resulted with maximum of 15.0 shoots. 90% regeneration frequency and shoot length of 6.0 cm were recorded per explant. Thus, the procedure described is a quick and reliable method which could be applied for efficient large scale propagation, genetic transformation assays and secondary metabolite production of Stevia.

Boosting Achene Yield and Yield Related Traits of Sunflower Hybrids through Boron Application Strategies

Effects of different boron (B) application methods on growth and yield of sunflower hybrids were checked out at Agronomic Research Farm, University of Agriculture, Faisalabad, Pakistan during spring, 2013. Field experiment was conducted by considering three sunflower hybrids viz., Patron 551, Patron 851 and S-278 along with different methods of B application i.e. no B application, seed treatment @ 0.05% B, soil B application @ 2 kg·ha-1 at sowing, soil B application @ 2 kg·ha-1 at ray floret stage and foliar application of B @ 200 mg·L-1 at ray floret stage. Uttermost plant height (150.78 cm), the number of leaves per plant (22.67) and stem diameter (1.62 cm) were accomplished when boron was soil applied @ 2 kg·ha-1 at sowing. Significantly higher head diameter (18.30 cm), number of achene per head (1266.44), 1000-achene weight (43.17 g) achene yield (2039.33 kg·ha-1), biological yield (9223.11 kg·ha-1) and harvest index (22.10%) were registered when boron was foliar applied @ 200 mg·L-1 at ray floret stage. Among sunflower hybrids, Patron 551 produced significantly higher growth and yield attributes as compared with Patron 851 and S-278 hybrids. This study suggested that the selection of Patron 551 hybrid with practicing boron foliar application @ 200 mg·L-1 at ray floret stage could be helpful in achieving the sunflower crop genetic potential.

Characterization of Water Melon (<i>Citrullus lanatus</i>) Genotypes under High Salinity Regime

For horticultural crops and especially for vegetables, salinity is dilemma. It is the most limiting factor for plant growth and development by producing reactive oxygen species and ultimately oxidative stress. In the present study, the screening of watermelon (Citrullus lanatus Thanb. Mavs.) Cultivars was observed for salt tolerance. Four salinity levels (1.5, 3, 4.5, and 6 dS·m-1 NaCl) and six cultivars (Crimson, Charleston Gray, Anarkali, Chairman, Sugar Baby and Champion) tested for screening. It was observed that all morphological attributes and ionic contents were severely affected. But it was revealed by statistical analysis that Charleston Gray was affected least while Champion was most salt sensitive cultivar due to oxidative stress and ionic toxicity. It is concluded that different genotypes under consideration vary in their ability to tolerate salt stress.

Economics of Different Genotypes of Cotton Planted under Various Planting Densities

A field experiment was conducted in order to evaluate the economics of different genotypes of cotton planted under various planting densities at Agronomic Research Area, University of Agriculture Faisalabad during the summer season in 2013. Sowing was done manually with the help of dibbling method on both sides of the bed in standing water, with bed distance of 75 cm. The crop was sown in May and the experiment comprised of following FH-142, FH-114 at various densities (S1 = 10 cm, S2 = 15 cm, S3 =20 cm, S4 = 25 cm, S5 = 30 cm). Data regarding net field benefit, benefit cost ratio, dominance analysis, and marginal rate of return were collected. The experimental results showed that maximum NFB of (Rs. 222,575), (Rs. 202,483) was achieved in FH-142 and FH-114 when planted at a plant spacing of 20 cm and 15 cm respectively. While the maximum benefit cost ratio (BCR) of 1.76 was found in genotype FH-142 at plant spacing of 20 and 25 cm and FH-114 depicted maximum BCR of 1.62 and 1.61 when planted at plant spacing of 15 and 20 cm, respectively. Dominance analysis of FH-142 planted at 10 and 15 cm while FH-114 at plant spacing of 10, 15 and 20 cm was dominated due to their lower net field benefits as compared to other treatments, while maximum marginal rate of return (1494%, 788%) by planting FH-142, FH-114 was obtained at 30 cm and 25 cm recorded respectively.

Overview of Strain Characterization in Relation to Serological and Molecular Detection of Citrus tristeza Closterovirus

Tristeza is a devastating viral disease in all the citrus growing countries throughout the world and has killed millions of citrus trees in severely affected orchards.The citrus species grafted on sour orange rootstock are affected by this disease.Predominantly,the sweet orange,grapefruit and lime trees grafted on sour orange exhibit severe symptoms like quick decline,vein clearing,pin holing,bark scaling and degeneration leading to variable symptoms.Symptomatic expression of Citrus tristeza virus(CTV)in different hosts has been attributed to virus isolates which are from severe to mild.Different serological and molecular assays have been deployed to differentiate the strains of CTV.Citrus tristeza virus is diversified towards its strains on the basis of biological,serological and molecular characterization.Phenotypic expression is due to genetic alteration and different molecular basis have now been adopted for strain differentiation.This review will give a brief idea about the different CTV isolates,their characterization based on nucleic acid and serological assays.Different methods along with salient features for strain characterization has also been reviewed.This review will also open the new aspects towards formulation of management strategies through different detection techniques.

Evaluation of Pear Varieties for Physiochemical Traits Grown under Climatic Conditions of Soon Valley, Pakistan

The study carried out aimed at characterizing the pear cultivars and to explore the specific cultivar most suitable to be commercially grown in Soon valley region. Nine pear varieties (Leconte, Bagugosha, Bartlet pear, Concord, Pear selection-1, Pear Red, Pear White, Kashmiri Nashpati and Kashmiri Nakh) were tested for their physiochemical quality attributes. The observations made during the study revealed that variety Bagugosha scored maximum (7.95, 8.10) in taste and flavor respectively. The same variety produced maximum fruit size (5081 mm2), fruit weight (205 g), soluble solid contents (15%) and total sugars (9.56%). However, fruit yield per plant was maximum (98.80 kg) in Bartlet pear variety and Bagugosha produced fruitweight of 60.20 kg. Titratable acidity was determined maximum (0.44%) in Kashmiri Nakh. Number of seeds were maximum (8.20) in Bartlet Pear as well as in Bgugosha. The exploration of this research study revealed that the Bagugosha is the prime quality cultivar to be suggested for commercial cultivation in Soon valley compared to all nine evaluated varieties.

Potential of Plant Growth Regulators on Modulating Rooting of <i>Rosa centifolia</i>

Rosa centifolia is grown for its flowers which are used for essential oil extraction. It is vegetatively propagated through its cuttings which are difficult to root. This study was designed to increase the rooting percentage of cuttings by applying plant growth regulators (PGRs) with different levels. In total 31 treatments with different concentrations (450 ppm, 700 ppm and 950 ppm) of indole butyric acid (IBA), indole acetic acid (IAA), naphthalene acetic acid (NAA) alone, in combination and with same concentrations of 6-benzylamino purine (BAP) were used. Healthy similar sized cutting of R. centifolia was treated in solution of PGRs by quick dip method and planted in polythene bags. The data for shoot length, shoot dry weight, number of roots, root length and root dry weight were recorded. All three levels (450 ppm, 700 ppm and 950 ppm) of IBA alone produced maximum results in case of all parameters as compared to all other treatments. Among three levels of IBA, 450 ppm concentration produced maximum shoot length (10.67 cm), shoot dry weight (3.02 g), number of roots (14.00), root length (11.90 cm) and root dry weight (0.50 g). Lower concentrations of plant growth regulators produced better results as compared to higher concentrations.

Foliar Application of Micronutrients Enhances Wheat Growth, Yield and Related Attributes

Wheat is one of the most essential foods in the world. To increase its productivity, nutrient management is one of the most important factors. To assess the possible role of micronutrients in improving wheat yield, an experiment was conducted to evaluate the wheat performance by foliar application of micronutrients. Treatments consist of T1 = No spray, T2 = Spraying plants with tube well water (control), T3 = Spraying plants with 1.6 kg FeSO4/100 L water/acre, T4 = Spraying plants with 3 kg ZnSO4 (21%)/100 L water/acre, T5 = Spraying plants with 1 kg MnSO4/100 L water/acre, T6 = Spraying plants with (FeSO4 + MnSO4), T7 = Spraying plants with (FeSO4 + ZnSO4), T8 = Spraying plants with (ZnSO4 + MnSO4), and T9 = Spraying plants with (FeSO4 + ZnSO4 + MnSO4). Results showed that foliar application of micronutrients substantially improved plant height, spike length cm, spikelets/spike, grains/spike, test weight, Tillers m-2, grain and biological as well as harvest index of wheat. Among treatments, foliar application of FeSO4 + ZnSO4 + MnSO4 remained comparatively better regarding yield related attributes of

Phosphorous and Foliar Applied Nitrogen Improved Productivity and Quality of Potato

Growth, yield and quality of potato are greatly affected by its nutritional management. Foliar application of urea reduces nitrogen losses and increases plant nitrogen use efficiency. This study was therefore planned to evaluate the effect of soil applied phosphorus (DAP) and foliar application of nitrogenous fertilizer (urea) on growth, yield and quality of potato. Experiment was comprised of four different treatments of phosphorus (DAP, 46% P) and nitrogen (urea, 46% N) including a control. Treatments were T0 (DAP 160 + Urea 300 kg/acre), T1 (DAP 160 + Urea 5 kg/acre), T2 (DAP 100 + Urea 6 kg/acre) and T3 (DAP 120 + Urea 8 kg/acre). DAP fertilizer was given as basal dressing at the time of sowing. Foliar applications of nitrogenous fertilizer (urea) were given after 30 of sowing with one week interval in five split doses. Results indicated that T3 remained better regarding productivity and quality of potato. The overall fertilizer efficacy regarding yield and quality was: T3 > T2 > T1 > T0. However, Vitamin C was found maximum in T0.

5-Aminolevulinic acid alleviates herbicide-induced physiological and ultrastructural changes in Brassica napus

It is well known that application of 5-aminolevuJinic acid （ALA） could promote the plant growth under abiotic stress in oilseed rape （Brassica napus L.）. However, the specifics of its physiological and ultrastructural regulation under herbi- cide stress conditions are poorly understood. In the present study, alleviating role of ALA in B. napus was investigated under four levels of herbicide propyl 4-（2-（4,6-dimethoxypyrimidin-2-yloxy） benzylamino） benzoate （ZJ0273） （0, 100, 200 and 500 mg L-1） with or without 1 mg L-1 ALA treated for 48 or 72 h. Results showed that after 48 h of herbicide stress, the growth of rape seedlings was significantly inhibited with the successive increases of the ZJ0273 concentrations from 0 to 500 mg L-1, but this inhibition was obviously alleviated by exogenous application of ALA. However, when treatment time prolonged to 72 h, the recovery effects of ALA could not be evaluated due to the death of plants treated with the highest concentration of ZJ0273 （500 mg L-1）. Further, the root oxidizability and activities of antioxidant enzymes （superoxide dismutase, perox- idase and ascorbate peroxidase） were dramatically enhanced by the application of 1 mg L-1 ALA under herbicide stress. Therefore, plants treated with ALA dynamically modulated their antioxidant defenses to reduce reactive oxygen species （ROS） accumulation and malondialdehyde （MDA） content induced by herbicide stress. Additionally, exogenously applied ALA improved the ultrastructure＇s of chloroplast, mitochondria and nucleus, and induced the production of stress proteins. Our results suggest that ALA could be considered as a potential plant growth regulator for the improvement of herbicide tolerance through alleviation of the physiological and ultrastructural changes induced by the herbicide in crop production.

Multi-strain Inoculation with PGPR Producing ACC Deaminase is More Effective Than Single-strain Inoculation to Improve Wheat (Triticum aestivum) Growth and Yield

Rhizosphere bacteria that colonize plant roots and confer beneficial effects are referred as plant growth promoting rhizobacteria(PGPR).Among all PGPR,some rhizobacteria have an ability to produce ACC deaminase enzyme.This enzyme catalyzes stress ACC into a-ketobutyrate and ammonia instead of letting it to be converted to ethylene.Ethylene level rises in plants under stress conditions i.e.,drought,salinity,poor soil fertility etc.As poor soil fertility is a big hurdle to achieve the optimum yield of crops,inoculation of ACC deaminase PGPR can overcome this problem to some extent.The aim of the current study was to examine the influence of multi-strain and single-strain inoculation of different ACC deaminase producing PGPR on wheat growth and yield.There were three PGPR strains,Enterobacter cloacae,Serratia ficaria and Burkholderia phytofirmans which were used as consortia and single-strain inoculations.The results showed that inoculation of E.cloacae+S.ficaria+B.phytofirmans significantly increased plant height(63%),spike length(61%),number of spikelets spike-1(61%),number of grains spike-1(131%),1000 grains weight(33%),grains yield(71%),straw yield(71%)and biological yield(68%)of wheat as compared to control.A significant improvement in N(37 and 200%),P(46 and 166%)and K(39 and 61%)of seeds and shoot respectively,validated the efficacious and more effective role of multi-strain(E.cloacae+S.ficaria+B.phytofirmans)inoculation over control.It is obviously concluded that multi-strain ACC deaminase producing PGPR inoculation is a better approach as compared to single-strain inoculation for the improvement in growth and yield of wheat.

Comprehensive screening and selection of okra (Abelmoschus esculentus) germplasm for salinity tolerance at the seedling stage and during plant ontogeny

The okra germplasm was screened for salinity tolerance at the seedling stage and during plant ontogeny.Substantial variation existed in okra for salinity tolerance at the seedling stage.An 80 mmol/L NaCl concentration was suitable for discriminating tolerant and non-tolerant okra genotypes.The pooled ranking of the genotypes,based on individual rankings for each trait(root and shoot length,germination percentage,and relative Na+ and K+)in individual NaCl concentrations,was effective for selecting tolerant genotypes.Genotypes selected at the seedling stage maintained their tolerance to NaCl during plant ontogeny,suggesting that screening of the germplasm entries and advanced breeding materials for salt tolerance at the seedling stage is effective.Among 39 okra genotypes,five were identified as the most tolerant genotypes and showed potential for use in breeding programs that focus on the development of salt-tolerant,high-yield okra cultivars.

Extraction of DNA suitable for PCR applications from mature leaves of Mangifera indica L.

Good quality deoxyribonucleic acid (DNA) is the pre-requisite for its downstream applications. The presence of high concentrations of polysaccharides, polyphenols, proteins, and other secondary me- tabolites in mango leaves poses problem in getting good quality DNA fit for polymerase chain reaction (PCR) applications. The problem is exacerbated when DNA is extracted from mature mango leaves. A reliable and modified protocol based on the cetyl- trimethylammonium bromide (CTAB) method for DNA extraction from mature mango leaves is described here. High concentrations of inert salt were used to remove polysaccharides; Polyvinylpyrrolidone (PVP) and β-mercaptoethanol were employed to manage phenolic compounds. Extended chloroform-isoamyl alcohol treatment followed by RNase treatment yielded 950?1050 μg of good quality DNA, free of protein and RNA. The problems of DNA degradation,contamination, and low yield due to irreversible binding of phenolic compounds and coprecipitation of polysaccharides with DNA were avoided by this method. The DNA isolated by the modified method showed good PCR amplification using simple se- quence repeat (SSR) primers. This modified protocol can also be used to extract DNA from other woody plants having similar problems.