Weed growth,herbicide efficacy,and rice productivity in dry seeded paddy field under different wheat stubble management methods

To ascertain the influence of wheat stubble management options and chemical weed control methods on weed growth and productivity of dry direct-seeded fine rice, a two years' field study was undertaken at the Agronomic Research Farm, University of Agriculture, Faisalabad, Pakistan in 2013 and 2014. Different wheat stubble management methods, viz., incorporation, burning and retention were executed during seed-bed preparation. While, herbicide treatments comprised of a weed check, weed free, pendimethalin followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl, and bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl. Results revealed that weed control efficacy of both herbicide treatments ranged from 84 to 94%. Herbicide treatments significantly reduced weed density(88–90%) and dry weight(86–88%), while improved the rice growth attributes compared with weed check. Application of bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention recorded 226 and 273% increase in kernel yield over weedy check in 2013 and 2014, respectively. In stubble incorporation, pendimethalin followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl was more effective in increasing(256–293%) rice yields over weedy check. Among different treatment combinations, the maximum net benefits(1 397.49~(–1) 472.22 USD ha~(–1)), net returns(636–700 USD ha~(–1)), benefit cost ratio(1.77~(–1).83) and marginal rate of return(2 187–2 330%) were recorded with the application of bispyribac sodium followed by fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention. In crux, application of bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention is efficient approach to control weeds, and get maximum rice productivity and net economic returns under dry seeded system.     

Chemical characterization of the essential oil from patchouli accessions harvested over four seasons

The genus Pogostemon of the Lamiaceae family includes several species known for their medicinal and aromatic properties. The species P. cablin is especially notable because the essential oil extracted from its leaves is internationally important and valuable, principally for the perfume and cosmetic industries. Because multiple factors can affect the chemical composition of the essential oil, the aim of this work was to evaluate the chemical variations in the essential oils of nine Pogostemon accessions harvested over four seasons. Two Pogostemon accessions (P. heyneanus, but received as P. cablin) and seven P. cablin accessions from different sources were evaluated. The transplants were planted in January 2008, and the harvests were conducted in May, August, and November 2008 and February 2009. The chemical composition of the essential oils was evaluated quantitatively and qualitatively. Patchoulol was the major compound from the four harvests of all of the P. cablin accessions. The principal compound from the accessions POG-001 and POG-006 was β-pinene. Two clusters were detected by multivariate analyses of the four harvests. Cluster I was formed by the accessions POG-001 and POG-006 (P. heyneanus), and Cluster II was formed by the accessions of P. cablin (POG-002, POG-014, POG-015, POG-016, POG-019, POG-021, and POG-022).     

A recombinant form of chagasin from Trypanosoma cruzi: inhibitory activity on insect cysteine proteinases

BACKGROUND: The activity of the major digestive cysteine proteinase detected in the intestinal tract of larvae of the bean weevil, Acanthoscelides obtectus (Say), was efficiently inhibited by the well-characterized cysteine proteinase synthetic inhibitor E-64 and also by a recombinant form of chagasin (r-chagasin), a tight-binding cysteine proteinase inhibitor protein from Trypanosoma cruzi. RESULTS: Incorporation of r-chagasin into an artificial diet system at 0.1 g kg(-1) retarded growth rate, decreased larval survival and led to complete mortality of A. obtectus at the end of the trial. The observed differences in growth rates occurred particularly in the first and second development stages. Artificial seeds containing high levels of r-chagasin (0.5-30 g kg(-1)) completely inhibited larval penetration. CONCLUSION: Together, the results reported in this paper support the hypothesis that the inhibitory activity of r-chagasin towards the major insect gut cysteine proteinase in vitro and in vivo is an accurate prediction of its insecticidal effects. The selectivity of this inhibitor against insect digestive proteinases supports the key role in parasite virulence by affecting the endogenous proteinase activity in its natural host.     

Delivery of epidermal neural crest stem cells (EPI-NCSC) to hippocamp in Alzheimer's disease rat model

Background: Alzheimer’s disease (AD) is characterized by progressive neuronal loss in hippocamp. Epidermal neural crest stem cells (EPI-NCSC) can differentiate into neurons, astrocytes and oligodendrocytes. The purpose of this study was to evaluate the effects of transplanting EPI-NCSC into AD rat model. Methods: Two weeks after induction of AD by injection of Amyloid-β 1-40 into CA1 area of rat hippocamp, Y-maze and single-trial passive avoidance tests were used to show deficit of learning and memory abilities. EPI-NCSC were obtained from the vibrissa hair follicle of rat, cultured and labeled with bromodeoxyuridine. When Alzheimer was proved by behavioral tests, EPI-NCSC was transplanted into CA3 area of hippocamp in AD rat model. The staining of EPI-NCSC markers (nestin and SOX10) was done in vitro. Double-labeling immunofluorescence was performed to study survival and differentiation of the grafted cells. Results: We showed that transplanted EPI-NCSC survive and produce many neurons and a few glial cells, presenting glial fibrillary acidic protein. Total number of granule cells in hippocamp was estimated to be more in the AD rat model with transplanted cells as compared to AD control group. We observed that rats with hippocampal damage made more errors than control rats on the Y-maze, when reward locations were reversed. Conclusion: Transplanted cells were migrated to all areas of hippocamp and the total number of granule cell in treatment group was equal compared to control group. Transplantation of EPI-NCSC into hippocamp might differentiate into cholinergic neurons and could cure impairment of memory in AD rat model.Key Words: Alzheimer’s disease, Cholinergic neuron, Hair follicle     

Zinc bioavailability in maize grains in response of phosphorous–zinc interaction

Phosphorous (P) and zinc (Zn) are plant nutrients that interact with each other in soil–plant systems. Such interactions may cause deficiency of one of the nutrients interacting with each other if interactions are antagonistic. In the present trial, a field experiment was conducted to investigate the interactive effect of Zn (0 and 16 kg ha^?1) and P (0 and 60 kg ha^?1) on growth, yield and grain Zn concentration of two maize (Zea mays L.) genotypes, i.e., Neelam (local) and DK‐6142 (hybrid). Growth and yield of both maize genotypes were increased by the application of Zn and P treatments compared with control, but Zn+P was more effective than their sole application. When compared to control, combined application of Zn+P increased grain Zn and P concentrations by 52% and 32%, respectively, averaged for the two genotypes. Single application of P decreased grain Zn concentration by 10% over control. Application of P and Zn particularly in combination decreased the grain [phytate] : [Zn] ratio and increased the estimated human Zn bioavailability in grains based on a trivariate model of Zn absorption in both maize genotypes. Conclusively, combined Zn+P application appeared more suitable for enhancing grain yield and agronomic Zn biofortification in maize grains. However, Zn fertilization aiming at increasing grain yield and grain Zn concentration should consider the genotypic variations and P rate.     

Resistance of <Emphasis Type="Italic">Solanum</Emphasis> species to <Emphasis Type="Italic">Cucumber mosaic virus</Emphasis> subgroup IA and its vector <Emphasis Type="Italic">Myzus persicae</Emphasis>

Sixty-nine tomato genotypes representing nine Solanum species were evaluated for resistance to Cucumber mosaic virus (CMV) subgroup IA and its aphid vector Myzus persicae. Resistance was assessed by visual scoring of symptoms in the field under natural conditions, and in the greenhouse by artificial inoculations through aphid M. persicae and mechanical transmissions in the year 2007 and 2009. Considerable variation in responses was observed among the evaluation methods used. Field evaluations were found liable to errors as different levels were observed for the same genotypes in the different years, however mechanical inoculation was found to be the most useful in identifying CMV subgroup IA resistance, in contrast aphid transmission was most useful in identifying insect transmission resistance. All genotypes observed as highly resistant to CMV subgroup IA in the field or through vector transmission became systemically infected through mechanical inoculations. Using mechanical inoculation, six genotypes (TMS-1 of S. lycopersicum, LA1963 and L06049 of S. chilense, LA1353, L06145 and L06223 of S. habrochaites) were found resistant and another six (L06188 and L06238 of S. neorickii, L06219 of S. habrochaites, L05763, L05776 and L06240 of S. pennellii) were found tolerant showing mild symptoms with severity index (SI) ranging 1-2 and with delayed disease development after a latent period (LP) of 18–30 days. However, these genotypes were found to be resistant to highly resistant in the field and through inoculation by M. persicae; and they also supported low population levels of M. persicae except TMS-1. Another nine genotypes (LA2184 of S. pimpinellifolium L., LA2727 of S. neorickii, LA0111, L06221, L06127 and L06231 of S. peruvianum L., LA1306, L06057 and L06208 of S. chmielewskii) showing a susceptible response after mechanical inoculation were highly resistant, resistant and tolerant after M. persicae transmission. The resistant genotypes, identified in the present study can be exploited in the breeding programmes aimed at developing tomato varieties resistant to CMV subgroup IA and broadening the genetic base of CMV-resistant germplasm. The differences observed between mechanical and aphid transmission suggests that one should consider both evaluation methods for tomato germplasm screening against CMV subgroup IA.     

Water stress and gibberellic acid effects on growth of fenugreek plants

Fenugreek plant is susceptible to water stress during the vegetative growth stages, since a soil matric potential lower than –0.3 MPa causes substantial reduction in growth parameters such as height, weight and total leaf area. Gibberellic acid (GA₃) application to the seeds before sowing caused slight changes in growth parameters as well as some physiological and biochemical aspects under water deficit conditions.Water stress decreased the area of leaves by reducing the number and volume of cells. Leaf growth was improved by GA₃ treatment by promoting the growth processes slightly. Photosynthetic pigments (Chlorophyll a and b, and carotenoids) in the leaves diminished and the concentrations of the main cations (Na⁺, K⁺, Ca²⁺ and Mg²⁺) were disturbed by a decreasing soil matric potential. Monosaccharides accumulated markedly under water stress, and GA₃ may have further stimulated such accumulation. A substantial reduction in total soluble nitrogen was accompanied by a marked increase in protein-N. The possible physiological and biochemical roles of such alterations in the chemical constituents are discussed. Received: 20 March 1998     

Identification of<Emphasis Type="Italic">Pseudomonas viridiflava</Emphasis> on tomato by traditional methods and enzyme-linked immunosorbent assay

Pseudomonas viridiflava is one of the causal agents of tomato stem necrosis in the eastern Mediterranean region of Turkey. The bacterium causes general wilting, yellowing of tomato plants, dark blotches on the pruning sites of the stem, browning, and hollowing of the pith.P. viridiflava strains, isolated from Antakya and Mersin, were identified by traditional methods and indirect enzyme-linked immunosorbent assay (ELISA). For indirect-ELISA, polyclonal antisera were produced against a regional isolate ofP. viridiflava (AD-OZ 3a). Using indirect-ELISA, the pathogenic bacterium was identified rapidly and safely from both pure culture and inoculated plants in 2 days. There was no cross reaction with other stem necrosis pathogens. With indirect-ELISA, the lower limit forP. viridiflava detection in pure culture was 10³ colony-forming units per milliliter. http://www.phytoparasitica.org posting Feb. 11, 2004.