The utility of Trichoderma spp. isolates to control of Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae)

Journal of Plant Diseases and Protection - The invasive ambrosia beetle, Xylosandrus germanus Blandford (Coleoptera: Curculionidae: Scolytinae), is a serious pest of hazelnut in Turkey, which is...     

Potato apical leaf curl disease: current status and perspectives on a disease caused by tomato leaf curl New Delhi virus

Journal of Plant Diseases and Protection - Potato apical leaf curl disease (PALCD) caused by a unique bipartite virus [tomato leaf curl New Delhi virus (ToLCNDV)] has emerged as a global threat....     

Effect of waxing and cellophane lining on chemical quality indices of citrus fruit

Effects of waxing of the fruit and of the use of cellophane for lining storage boxes on chemical quality indices (including ethanol and acetaldehyde) and flavour scores of Feutrell's Early mandarin during storage at room conditions were determined. Maximum changes during storage of waxed mandarins in film-lined boxes occurred in ethanol contents which were followed by acetaldehyde, total soluble solids (TSS)/acid ratio, TSS and acid contents. There were negative and highly significant linear relationships between flavour scores, and ethanol content and acetaldehyde content. The r² values indicated that over 90% of the variation in flavour scores could be explained by changes in ethanol and acetaldehyde contents whereas only 50% of the variation in flavour scores could be predicted by changes in total acid and TSS/acid ratios. There were comparatively greater increases in ethanol and acetaldehyde content, lesser increases in TSS and greater decreases in total solids of waxed mandarins during storage than those of unwaxed fruits stored in film lined boxes; the ratio of ethanol and acetaldehyde (E/A) of waxed mandarins was also higher. Decreases in citric acid content during storage correlated linearly to increases in the E/A ratio at the 1% level of significance indicating that citric acid metabolism was affected during storage of waxed mandarins at ordinary room conditions.     

Neopestalotiopsis clavispora and Pseudopestalotiopsis camelliae-sinensis causing grey blight disease of tea (Camellia sinensis) in Malaysia

European Journal of Plant Pathology - Tea (Camellia sinensis) is a popular and extensively consumed beverage in Malaysia along with many other countries around the world. Grey blight is one of the...     

Amino Acid Composition of Developing Larval Freshwater Prawn Macrobrachium rosenbergii

Abstract.— Amino acid profiles of freshwater prawn Macrobrachium rosenbergii were determined during early larval stages (I-IX) to provide some baseline biochemical information of the growing larvae. The larvae obtained from several females were stocked into three 250-L tanks at a density of 30 larvae/L. The feeding regime consisted of newly hatched Artemia nauplii and egg custard containing 5% cod liver oil. For each developmental stage, larval samples from each experimental tank were pooled, freeze dried and after acid hydrolysis, the quantification of amino acids was done by a reverse phase high performance liquid chromatography ( N = 2). The highest represented of the total amino acids were for glutamic acid and phenylalanine (with cystine) with ranges from 13.4–16.6 and 9.7–11.5%, respectively, whereas tryptophan (1.4–1.6%). methionine (1.4–2.7%) and histidine (2.9–4.2%) were relatively lower. The levels of the following essential amino acids did not significantly change during larval development: arginine, leucine, phenylalanine (plus cystine), threonine, tryptophan and valine. Despite statistically significant changes that were observed in levels of some amino acids, amino acid composition appeared to be relatively unchanged during the larval growth. The results may suggest that the amino acid requirements of the freshwater prawn is relatively constant during larval life and can be satistied by a suitable protein source that resembles the larval amino acid profile.     

Dihydrooxadiazines: Octopaminergic system as a potential site of insecticidal action

Dihydrooxadiazines are structural analogs of octopamine and were compared with octopamine for their ability to compete with [³H]dihydroergocryptine ([³H]DHE) for binding sites on DHE-sensitive receptors, to stimulate adenylate cyclase activity in nervous system homogenates of Periplaneta americana L., and to modulate the action of the peptide proctolin on the oviducal muscles of Locusta migratoria L. [³H]DHE binding was inhibited by low concentrations (μM range) of octopamine, phentolamine, N-demethylchlordimeform (DCDM) and several dihydrooxadiazines. The tested dihydrooxadiazines acted as aminergic agonists in stimulating cyclic AMP production in cockroach nervous system homogenates and did not show additive effects with octopamine, whereas additivity was observed with 5-hydroxytryptamine. The relative potency of octopaminergic antagonists, including mianserin, cyproheptadine, phentolamine, and gramine, to block octopamine-mediated elevation of cyclic AMP production was similar to the rank-order potency of the same antagonists to inhibit dihydrooxadiazine-mediated elevation of cyclic AMP production. Octopamine, 2-(4-bromophenyl)-5,6-dihydro-4H-1,3,4-oxadiazine (4-Br-PDHO), and 8-Br-cyclic AMP caused increased phosphorylation of proteins that are phosphorylated by exogenously added cyclic AMP-dependent protein kinase. These results indicate that the dihydrooxadiazine-induced rise in cyclic AMP levels in homogenates of the cockroach nervous system results directly in activation of an endogenous cyclic AMP-dependent protein kinase. 4-Br-PDHO behaved similarly to octopamine in modulating the action of proctolin-induced contractions in locust oviducal muscles. These observations suggest that dihydrooxadiazines act as octopamine agonists and have an octopaminergic action in modulating the action of proctolin. Thus, it is proposed that dihydrooxadiazines exert at least part of their insecticidal and miticidal actions through interaction with the octopaminergic system.     

In-vitro Metabolism of a Novel Monocrotophos Derivative by Rat and Japanese Quail

NADPH-dependent inhibition of hepatic microsomal carboxylesterase by a derivative of monocrotophos (coded as RPR-5) was studied in rat and Japanese quail as a measure of monooxygenase-catalysed activation of RPR-5. There was NADPH-dependent inhibition of hepatic microsomal α-naphthyl acetate esterase (carboxylesterase) both in rat and quail, indicating monooxygenase-catalysed formation of an oxon that subsequently phosphorylated α-NaE. The pattern of in-vitro metabolism of ¹⁴C-labelled RPR-5 by 11000g supernatant (11-S), microsomes and 105000g supernatant (105-S) fractions of rat and quail livers suggested the involvement of microsomal monooxygenases and carboxylesterases. A radiolabelled metabolite (M2) was tentatively identified as an acid produced by carboxyl esterase attack. In rat, metabolism by microsomal and cytosolic (105-S) carboxylesterases appeared to predominate with relatively little oxidative metabolism. In quail, putative microsomal carboxylesterase hydrolysis of RPR-5 was much lower than in the rat with almost neglible hydrolysis by cytosolic fractions. Also, production of M₂ by quail microsomes was substantially reduced after addition of NADPH, suggesting inhibition of a carboxyl esterase by the oxon of RPR-5. Differences in this detoxification of RPR-5 between rat and quail may be an important factor in determining selective toxicity and the results underline the importance of relating metabolism to toxicity when selecting animal models for toxicity testing.     

Potential of advanced breeding lines of bread‐making wheat to accumulate grain minerals (Ca,Fe, Mg and Zn) and low phytates under Mediterranean conditions

About 3 billion people may suffer from micronutrient deficiency such as Ca, Fe, Mg or Zn, caused not only by a mineral deficiency in staple food but also by a high content of phytates which bind those minerals and inhibit their absorption. With the aim of evaluating the potential of new cultivars of bread‐making wheat to accumulate those minerals and low phytates, nine advanced breeding lines from an ongoing Portuguese breeding program were studied during 2 years in a field experiment. A wide genetic variability was found between the studied genotypes in all the parameters studied, especially grain yield (ranging on average between 2,027 and 3,209 kg/ha) and grain Mg and Zn concentrations (ranging on average between 1,070 and 1,336 mg/kg, and 23.4 and 30.7 mg/kg, respectively). In global terms, the cultivars with best performance, and therefore, the most potentially suitable to be used in a breeding program, were the Cultivars 3 and 4. However, such a potential varied depending on the analysed trait, and it was clearly influenced by the climatic conditions. The consumption of 100 g of Cultivar‐4 produced under the most favourable conditions might provide a 5.2% of Ca, 26.4% of Fe, 38.9% of Mg and 31.9% of Zn of the recommended daily intakes, with a very good bioavailability for Fe and Ca, but low for Mg and Zn.     

Morphology,phylogeny and pathogenicity of Fusarium species from Sansevieria trifasciata in Malaysia

Leaf blight is a common disease affecting Sansevieria trifasciata in many countries, including Malaysia. In the present study, Fusarium isolates were consistently recovered from the diseased leaves collected from various locations throughout the country. Based on morphology and multigene phylogenetic analysis using mitochondrial small subunit (mtSSU), intergenic spacer region (IGS) and translation elongation factor 1-α (TEF1-α) gene sequences, seven Fusarium species were identified, with F. oxysporum being the most prevalent (67.6%) among 34 isolates. Pathogenicity tests resulted in the discovery of pathogenic isolates that belonged to F. oxysporum, F. proliferatum, and F. pseudocircinatum, whereas all isolates of F. brachygibbosum, F. concentricum, F. mangiferae, and F. solani were nonpathogenic. The results suggest that several Fusarium species are accountable for causing disease on S. trifasciata in Malaysia.