Insecticide resistance inFrankliniella occidentalis: Corroboration of laboratory assays with field data and cross-resistance in a cypermethrin-resistant strain

Field efficacy of five insecticides to a greenhouse strain ofFrankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) of known resistance status was studied. In a greenhouse trial, the mortality of aF. occidentalis strain (Uncali) which exhibited resistance only against cypermethrin in laboratory assays, reached 56%, 68%, 82%, 94% and 99%, 24 h after application of abamectin, cypermethrin, endosulfan, malathion and methomyl, respectively. In the laboratory, for larval mortality equal to that achieved in the field, much lower doses — half of the field dose of cypermethrin and endosulfan, and one-third and one-sixth of malathion and methomyl, respectively, were required in topical application. Because of differences between laboratory and field responses ofF. occidentalis to insecticides, a sound resistance evaluation program to determine field efficacy of insecticides is needed. Resistance increased 28.0- and 139.3-fold at LC₅₀ in theF. occidentalis strain subjected to 27 and 44 cycles of cypermethrin selection, respectively. A slight cross-resistance of two- to threefold was found with endosulfan, malathion and methomyl and no cross-resistance was observed with abamectin. http://www.phytoparasitica.org posting August 4, 2008.     

Simultaneous Determination of Phorate and Oxyfluorfen in Well Water Samples with High Accuracy by GC-MS After Binary Dispersive Liquid-Liquid Microextraction

The potential risk of pesticides to cause harm to humans and other organisms even at trace levels calls for sensitive and accurate analytical techniques for their simultaneous qualitative and quantitative determinations. In this study, a sensitive binary dispersive liquid-liquid microextraction (B-DLLME) strategy was developed for the simultaneous determination of phorate and oxyfluorfen by gas chromatography mass spectrometry after extraction/preconcentration from aqueous solution. An experimental design was used to optimize parameters of the B-DLLME method to obtain maximum outcome. Under the optimum conditions of B-DLLME, the limit of detection (LOD) for phorate and oxyfluorfen were found to be 0.41 μg L^?1 and 0.54 μg L^?1, respectively. The detection limits correlate to about 37 and 73 folds enhancement in detection powers when compared to direct GC-MS determination of phorate and oxyfluorfen, respectively. In order to find out the applicability of developed method to real samples, recovery tests were performed for 20 μg L^?1 of phorate and oxyfluorfen spiked in well water samples. Percent recovery values were found to be 94.5% for phorate and 101.9% for oxyfluorfen.     

Volatile organic compounds in watermelon (Citrullus lanatus) grafted onto 21 local and two commercial bottle gourd (Lagenaria siceraria) rootstocks

Summary

Volatile organic compounds (VOCs) are responsible for flavour development in watermelon (Citrullus lanatus). The objective of this study was to investigate the rootstock effects of 21 local bottle gourd [Lagenaria siceraria (Molina) Standl.] accessions collected from the Mediterranean region (Turkey) on the concentrations of VOCs in watermelon over 2 years. The watermelon cultivar ‘Crimson Tide’ was used as the scion and two commercial bottle gourd rootstocks were also used for comparison. The VOCs in each rootstock-scion combination were analysed using static headspace (SHS) and gas chromatography-mass spectrometry (GC-MS). A total of 24 VOCs were identified in watermelon fruit, including 11 aldehydes, seven alcohols, four ketones, one heterocyclic compound, and one acid. Acetaldehyde (25.9 – 39.5% of the total peak areas), propanal (5.0 – 8.3%), 2-propanone (2.5 – 4.9%), pentanal (2.1 – 3.6%), hexenal (14.5 – 22.6%), (E)-2-hexenal (0.4 – 2.3%), 6-methyl-5-hepten-2-one (10.0 – 19.05%), nonanal (1.6 – 4.4%), (Z)-6-nonenal (4.0 – 9.8%), (E)-2-nonenal (0.6 – 2.0%), (E,Z)-2,6-nonadienal (2.1 – 3.7%), (Z)-6-nonenol (1.0 – 3.2%), and (E,Z)-3,6-nonadienol (1.0 – 3.7%) were the most abundant VOCs found in all watermelon scions. There was no significant effect (P ≥ 0.05) of rootstock on the concentrations of acetaldehyde, propanal, pentanal, heptanal, ethanol, 1-pentanol, 2-propanone, 2-pentyl furan, or acetic acid. Propanal, 2-propanone, and acetic acid were identified as VOCs in watermelon for the first time. Hexanal, (Z)-6-nonanal, and 6-methyl-5-hepten-2-one concentrations were strongly affected by rootstock. The results showed that the local bottle gourd accessions 07-06 and 31-09, in particular, were the most promising genotypes in terms of producing favourable VOCs. Except for the local bottle gourd accessions 33-35, 01-17, and 07-04, the other 18 gourds accessions had high potential as rootstocks for breeding programmes in watermelon with regard to desirable VOC concentrations. Rootstock 31-09 should be considered for commercial production in terms of improved disease resistance, fruit yield, and fruit quality.     

Isolation and partial characterization of excretory/secretory antigens of Gastrothylax crumenifer

The present study was carried out to identify the excretory/secretory (E/S) antigens of the rumen infecting digenetic trematode Gastrothylax crumenifer that may be useful for the immunodiagnosis of rumen amphistomosis particularly during the pre-monsoon season during which this rumen parasite stops shedding eggs. The in vitro released E/S proteins were purified on a Sephadex G-200 column. The gel filtration profile revealed three distinct fractions F1-F3 where F1 and F3 appeared as sharp peaks while the F2 fraction was dispersed. The antibody titre against each of the purified E/S fractions was determined by ELISA using anti-whole E/S polyclonal antibodies raised in rabbit. Among the three fractions, the antibody titre against F1 was highest (1:12,800) whereas IgG titre was very low (1:50) for fraction F2 and F3 (1:100). Of the total polypeptides resolved on gradient SDS-PAGE, only a few antigenic polypeptides were detected in each fraction with hyperimmune anti-serum as revealed by Western Blot analysis. However, a 33 kDa antigen detected in each fraction appeared to be immunodominant which could be exploited for the diagnosis of the pouched amphistome.     

Influence of vitamin E and vitamin E-selenium combination on arginase activity,nitric oxide level and some spermatological properties in ram semen

The effects of vitamin E and vitamin E-selenium combination on seminal plasma arginase activity and nitric oxide level and some spermatological properties in rams were investigated in this study. For control group, animals were injected intramuscularly with physiological saline. For vitamin E group, rams were injected intramuscularly with 300 mg/ram vitamin E. For vitamin E + selenium group, animals were injected intramuscularly with 5 ml/ram vitamin E + selenium. The semen was collected by artificial vagina at 1st, 4th, 24th, 48th and 72nd hr after administration in each group. Significant decreases in seminal plasma arginase activity (at 1st, 24th and 48th hr), nitric oxide level (at 72nd hr) and abnormal sperm rate (at 1st, 24th and 72nd hr), and significant increases in semen volume (at 24th hr), semen mass activity (at 24th and 48th hr), sperm motility (at 24th, 48th and 72nd hr) and concentration (at 1st hr) were observed in vitamin E group compared with control group. Similarly, significant increase in semen volume (at 1st, 24th and 48th hr), mass activity, (at 48th hr), motility (at 48th and 72nd hr) and concentration (at 4th, 24th and 48th hr), and significant decrements in abnormal sperm rate (at 1st, 24th, 48th and 72nd hr), seminal plasma nitric oxide level (at 1st, 4th, 24th and 48th hr) and semen pH (at 24th and 48th hr) were detected in vitamin E + selenium group in comparison to the control group. As a result, it is suggested that vitamin E and/or vitamin E + selenium applications may improve reproductive performance.     

Soil determinants for distribution of Halocnemum strobilaceum Bieb. (Chenopodiaceae) around Lake Tuz, Turkey

In this study we aimed to reveal the ranges and effectiveness of soil parameters on the distribution of H. strobilaceum. Halocnemum strobilaceum Bieb. is a widespread species in saline habitats and the distribution pattern of this halophytic species around Lake Tuz in Central Anatolia was examined according to the soil characteristics. pH, electrical conductivity, soil humidity, salt percentage, soluble Ca2+, Mg2+, Na+, K+, CO3(2-), HCO3(-), Cl(-) and SO4(2-) values, total cations, cation exchange capacity, sodium adsorption ratio, exchangeable Na+, K+, Ca2+ and Mg2+ values were the examined soil properties. The most effective soil parameters for flowering period were found as Na, SO4, total cations, SAR and EC and for seed bearing period as EC, Mg, total cations, Cl, Na, SO4 and salt (%) content of the soil.     

Molecular approaches in identifying leaf rust resistance genes in Russian wheat varieties

Russian soft wheat varieties are screened with the use of molecular markers of Lr genes. A low genetic diversity is found among leaf rust resistant varieties, in which genes Lr9 and Lr19 dominate. There are no highly effective genes Lr25, Lr29, and Lr39(41) and adult plant resistance genes Lr37 and Lr21 in the studied varieties. Among genes with limited effectiveness, the most prevalent are genes Lr10 and Lr26, respectively in 45 and 10% of the varieties.     

Combining ability analysis to identify suitable parents for heterosis in seed cotton yield,its components and lint % in upland cotton

Combining ability and heterosis were studied in a 6 × 6 diallel cross to see the nature of gene action in Upland cotton (Gossypium hirsutum L.) during 2002 to 2004. Analysis of variance revealed highly significant differences among all the F₁ and F₂ hybrid means and their respective six parental values for all the traits examined. In both generations, the mean squares due to general combining ability (GCA) and specific combining ability (SCA) were also highly significant. SCA genetic variances were greater than GCA and more important for the traits, i.e. boll weight, boll number and seed cotton yield per plant, showing the predominance of non-additive gene action. Lint % in both generations and boll weight in F₂s only were controlled by additive type of gene action due to maximum GCA variances. Cultivar CIM-1100 was found to be the best general combiner and its utilization produced valuable hybrids with desirable SCA in both generations. F₁ and F₂ hybrids, viz., CIM-1100 × CRIS-9, CIM-1100 × FH-682, CIM-1100 × BH-36 and CIM-109 × CIM-1100 as high × low and low × high parents performed well in SCA determination, outstanding mean performance and heterosis. Better SCA effects associated with useful heterosis were more pronounced for yield traits. In F₁ hybrids, maximum heterosis was observed for seed cotton yield followed by boll number, boll weight and lint %. The heterosis over better parent was +3.13 to +65.63% for bolls per plant, +0.75 to +24.40% for boll weight, +0.82 to +115.22% for seed cotton yield and +0.27 to +3.88% for lint %. Involvement of CIM-1100 in most of the F₁ and F₂ hybrids resulted in the synthesis of superior genotypes for most of the traits studied. Inbreeding depression was elevated in good performing hybrids and was the highest for seed cotton yield. Highest yielding F₁ hybrids yielded lesser in the subsequent generation due to over-dominance and inbreeding depression, whereas moderate yielding F₁ hybrids were found more stable even passing through process of segregation due to additive gene action. The combined performance of F₁ and F₂ hybrids could be a good indicator to identify the most promising populations to be utilized either as F₂ hybrids or as a resource population for further selection.     

Allelic variation and composition of HMW-GS in advanced lines derived from d-genome synthetic hexaploid / bread wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The objective of this study was to identify allelic variations at Glu-1 loci of wheat (Triticum aestivum L.) advanced lines derived from hybridization of bread wheat and synthetic hexaploid wheats (2n = 6x = 42; AABBDD). Locally adapted wheat genotypes were crossed with synthetic hexaploid wheats. From the 134 different cross combinations made, 202 F₈ advanced lines were selected and their HMW-GS composition was studied using SDS-PAGE. In total, 24 allelic variants and 68 HMW-GS combinations were observed at Glu-A1, Glu-B1, and Glu-D1 loci. In bread wheat, the Glu-D1 locus is usually characterized by subunits 1Dx2+1Dy12 and 1Dx5+1Dy10 with the latter having a stronger effect on bread-making quality. The subunit 1Dx5+1Dy10 was predominantly observed in these advanced lines. The inferior subunit 1Dx2+1Dy12, predominant in adapted wheat germplasm showed a comparative low frequency in the derived advanced breeding lines. Its successful replacement is due to the other better allelic variants at the Glu-D1 locus inherited in these synthetic hexaploid wheats from Aegilops tauschii (2n = 2x = 14; DD).     

Status of Lipid Peroxidation, Antioxidants, and Oxidation Products of Nitric Oxide in Equine Babesiosis: Status of Antioxidant and Oxidant in Equine Babesiosis

Equine babesiosis is a tick-borne protozoal disease of horses caused by Theileria equi and Babesia caballi. The disease is endemic in most tropical and subtropical areas. The aim of this paper is to assess the antioxidant status, lipid peroxidation, and oxidation products of nitric oxide (NO) in horses and mules naturally infected with T. equi and B. caballi. East and Southeast Anatolian horses and mules living in rural region of the Eastern border of Turkey were used as the material for this study. These animals are used as pack animal (3–7 years of age). Infected animals were in acute or subacute infection period. In the current study, malondialdehyde (MDA), oxidation products of NO (nitrate and nitrite), serum glutathione (GSH), vitamin E, and retinol levels were analyzed in 58 equids (horse and mule) infected with T. equi and B. caballi as well as in 44 healthy equids. Compared with controls, the level of MDA and nitrate increased significantly (P < .01, P < .05, respectively), whereas GSH concentration and levels of vitamin E decreased significantly (P < .01). There was no significant change in the level of nitrite and retinol between two groups. The results of the current study suggest that in equids infected with T. equi and B. caballi, this alteration in the lipid peroxidation, oxidants, and antioxidants may be related to the host's defenses against parasitic infection and may play a central role in the pathologic conditions associated with babesiosis.