Competitive ability of some cover crop species against Asystasia gangetica and Pennisetum polystachion

Abstract

Asystasia gangetica and Pennisetum polystachion are the most troublesome weeds in oil palm plantations in Malaysia and establishment of cover crops under oil palms is an integral part of sustainable weed management in plantations. Replacement-series experiments were conducted to evaluate the mode and strength of competitiveness of four legume cover crop species, Calopogonium caeruleum, Centrosema pubescens, Mucuna bracteata and Pueraria javanica, and one soft grass species, Axonopus compressus, against Asystasia gangetica and Pennisetum polystachion. Relative yield, relative yield total and relative crowding coefficient were calculated with reference to shoot biomass. Asystasia gangetica was a consistently weaker competitor than Pennisetum polystachion. The legume cover crop species had higher relative yield when grown in mixtures, whereas the yield of Asystasia gangetica was lower in mixtures with legumes than in monoculture. The higher competitiveness of legumes was due to greater canopy height and leaf area index. Centrosema pubescens was a slightly weaker competitor than the other legumes. Although leaf area per plant of Centrosema pubescens did not differ from that of other three legumes, canopy height and blocking photosynthetically active radiation to the soil surface were lower. When grown with a cover crop for 12 weeks, dry weight per plant, leaf area and shoot number of Pennisetum polystachion increased as its proportion decreased in mixtures. Relative yield data indicated that Pennisetum polystachion is a strong competitor. Axonopus compressus was less susceptible to Pennisetum polystachion interference than the legumes. All cover crop species studied proved highly competitive against Asystasia gangetica, but none could compete against Pennisetum polystachion. The study confirms the feasibility of using a cover crop for management of Asystasia gangetica.     

Growth and micronutrient acquisition of some apple varieties in response to gradual in vitro induced salinity

Growth and micronutrient acquisition of some apple (Malus dometsica Borkh) varieties (Galla, MM 111, MM I06, M 26, and M6 York) were studied under gradually in vitro induced NaCl (from 0, 50 to 100 mM) salinity. Microshoot dry weight tended to increase with increasing salinity level in all varieties except in M 26 and M6 York as some decline was obtained at 100 mM NaCl. Shoot proliferation was decreased significantly in Galla at 100 mM NaCl and at both salinity levels in M 26 compared to the control (0 mM). A significant decrease in shoot zinc (Zn) acquisition with increasing salinity level was obtained in all varieties except MM 111. M6 York and MM 111 decreased their copper (Cu) acquisition significantly at 50 mM NaCl and then increased at 100 mM salinity level. Meanwhile, a significant decrease in Cu acquisition with increasing NaCl concentration was obtained in Galla and M 26. Galla, MM 106, and M 26 showed a significant increase in manganese (Mn) acquisition at 50 mM NaCl followed by a decrease at 100 mM salinity level. On the other hand, Mn acquisition continued to decrease significantly in MM 111 while M6 York increased its Mn acquisition with increasing salinity. M 111 and M6 York showed a significant decrease in iron (Fe) acquisition at 50 mMNaCl followed by an increase at 100mM NaCl. Galla and M 26 continued to decrease Fe acquisition with elevated salinity level, whereas Fe in MM 106 increased with salinity.     

REPRODUCTIVE ALLOCATION AND NUTRIENT RELATIONSHIPS IN CUPHEA: A SEMI-DOMESTICATED OILSEED CROP

Interrelationships between ontogeny, allometric mass, and carbon (C): nitrogen (N): phosphorus (P) ratios were quantified in Cuphea, a semi-domesticated indeterminate and phenotypically plastic potential oilseed crop. Relative growth rate and net assimilation rate were estimated as functions of growth stages, phenotypic traits and C:N:P ratios. Ontogenically, N:P ratios in reproductive and metabolic tissues were least variable and were mainly affected by allometric leaf mass and relative growth rate. Reproductive mass is best predicted by allometric stem mass and C:N ratio in structural and metabolic tissues; whereas, net assimilation rate is best predicted by allometric total branch length and relative growth rate. The conservative N:P ratios found in reproductive and metabolic tissues are important in determining reproductive allocation in Cuphea. Large antagonistic effects of C:N on N:P ratios found in different plant tissues suggest that maximum reproductive allocation can be attained by manipulating N:P ratio during ontogeny. A greater investment of resources in reproduction may be possible for this semi-domesticated crop if nutrient and mass allocation to supporting stems and roots can be altered for the benefit of reproductive biomass.     

Antibodies to Schmallenberg virus in domestic livestock in Turkey

This, partly retrospective study, was designed to determine the seroprevalence of Schmallenberg virus (SBV), a new Orthobunyavirus first reported in Germany in late 2011, in domestic ruminants from the Middle Black Sea, West, and Southeast regions of Turkey. An indirect enzyme-linked immunosorbent assay was used to screen serum samples collected from slaughterhouse animals between 2006 and 2013. The overall seroprevalence was 335/1,362 (24.5 %) with 325/816 (39.8 %), 5/307 (1.6 %), 3/109 (2.8 %), and 2/130 (1.5 %) recorded in cattle, sheep, goats, and Anatolian water buffalo, respectively. This is the first study to demonstrate the presence of antibodies to SBV in Turkish ruminants; it indicates that cattle are more susceptible to infection than sheep, goats, or buffalo and that exposure of domestic ruminants to SBV in Turkey may have occurred up to 5 years prior to the first recorded outbreak of the disease in 2011.     

Distribution of Prosaposin mRNA in the Central Nervous System of the Pigeon (Columba livia)

Bioassay and immunohistochemical studies have detected the presence of prosaposin in the central nervous system (CNS) of mammals. Here, first time, we have determined the partial cDNA sequence of pigeon prosaposin and mapped the distribution of its mRNA in the pigeon CNS. The predicted amino acid sequence of pigeon prosaposin showed 93 and 60% identity to chicken and human prosaposin, respectively. In situ hybridization, autoradiograms showed that the prosaposin mRNA expression was found in the olfactory bulb, prepiriform cortex, Wulst, mesopallium, nidopallium, hippocampal formation, thalamus, tuberis nucleus, pre‐tectal nucleus, nucleus mesencephalicus lateralis, pars dorsalis, nucleus isthmi, pars parvocellularis and magnocellularis, Edinger–Westphal nucleus, optic tectum, cerebellar cortex and nuclei, vestibular nuclei and gray matter of the spinal cord. These results suggest that the cDNA sequence of pigeon prosaposin is comparable to other vertebrates, and the general distribution pattern of prosaposin mRNA resembles those are found in mammals.     

A review of oxalate poisoning in domestic animals: tolerance and performance aspects

Published data on oxalate poisoning in domestic animals are reviewed, with a focus on tolerance and performance. Oxalic acid is one of a number of anti‐nutrients found in forage. It can bind with dietary calcium (Ca) or magnesium (Mg) to form insoluble Ca or Mg oxalate, which then may lead to low serum Ca or Mg levels as well as to renal failure because of precipitation of these salts in the kidneys. Dietary oxalate plays an important role in the formation of Ca oxalate, and a high dietary intake of Ca may decrease oxalate absorption and its subsequent urinary excretion. Oxalate‐rich plants can be supplemented with other plants as forage for domestic animals, which may help to reduce the overall intake of oxalate‐rich plants. Non‐ruminants appear to be more sensitive to oxalate than ruminants because in the latter, rumen bacteria help to degrade oxalate. If ruminants are slowly exposed to a diet high in oxalate, the population of oxalate‐degrading bacteria in the rumen increases sufficiently to prevent oxalate poisoning. However, if large quantities of oxalate‐rich plants are eaten, the rumen is overwhelmed and unable to metabolize the oxalate and oxalate‐poisoning results. Based on published data, we consider that <2.0% soluble oxalate would be an appropriate level to avoid oxalate poisoning in ruminants, although blood Ca level may decrease. In the case of non‐ruminants, <0.5% soluble oxalate may be acceptable. However, these proposed safe levels of soluble oxalate should be regarded as preliminary. Further studies, especially long‐term studies, are needed to validate and improve the recommended safe levels in animals. This review will encourage further research on the relationships between dietary oxalate, other dietary factors and renal failure in domestic animals.     

Prospects of Marine Sterols against Pathobiology of Alzheimer’s Disease: Pharmacological Insights and Technological Advances

Alzheimer’s disease (AD) is a degenerative brain disorder characterized by a progressive decline in memory and cognition, mostly affecting the elderly. Numerous functional bioactives have been reported in marine organisms, and anti-Alzheimer’s agents derived from marine resources have gained attention as a promising approach to treat AD pathogenesis. Marine sterols have been investigated for several health benefits, including anti-cancer, anti-obesity, anti-diabetes, anti-aging, and anti-Alzheimer’s activities, owing to their anti-inflammatory and antioxidant properties. Marine sterols interact with various proteins and enzymes participating via diverse cellular systems such as apoptosis, the antioxidant defense system, immune response, and cholesterol homeostasis. Here, we briefly overview the potential of marine sterols against the pathology of AD and provide an insight into their pharmacological mechanisms. We also highlight technological advances that may lead to the potential application of marine sterols in the prevention and therapy of AD.     

Potential use of exogenous lipases for DATEM replacement to modify the rheological and thermal properties of wheat flour dough

The effect of two lipases and DATEM at different concentrations on the rheological and thermal properties of white and whole wheat flour doughs was determined by farinograph, extensograph, texture analyzer and differential scanning calorimetry. Lipases provided similar or better results than that of DATEM on decreasing softening degree and stickiness, and increasing stability, maximum resistance to extension and hardness. Extensibility and energy did not change with lipases, but decreased with DATEM. Lipases and DATEM slightly modified the transition temperatures and enthalpies of ice-melting and starch gelatinization, but significantly increased the moisture and unfrozen water contents, and decreased the solid concentration in unfrozen water. The greatest effect of lipases was observed on decreasing the peak temperature and increasing the enthalpy of amylose–lipid complex dissociation. The changes in the rheological and thermal properties were almost independent of the concentration levels tested, and were mostly reduced when whole wheat flour was used. The improvement in the dough properties by lipases is possibly related to the in situ formation of surface active compounds from endogenous flour lipids. Presumably, these compounds are already located in the right positions in dough, where they might have higher interaction potentials than DATEM with the dough components.     

In vitro dephytinization and bioavailability of essential minerals in several wheat varieties

Twelve wheat varieties were studied for their phytic acid, calcium, iron, zinc, copper and phosphorus contents, which respectively ranged between 114–166, 25.1–53.5, 3.41–5.55, 0.71–3.00, 0.65–1.32 and 298–314 mg/100 g. The molar ratios as Ca:Phy, Phy:Fe, Phy:Zn, Phy:Cu were found to be 0.14–0.29, 1.96–3.86, 5.11–20.5 and 13.0–23.9, respectively. Significant dephytinization, ranging between 35.3 and 69.3% in different varieties, was achieved on exogenous enzymatic treatment. Enzymatic dephytinization in the in vitro simulated gastrointestinal digestion resulted in significant increase in the bioavailability of essential minerals. The increase in bioavailability of calcium, iron, zinc and copper on exogenous enzymatic dephytinization ranged between, respectively (x-folds): 1.30–1.96, 1.11–1.52, 1.22–1.78 and 1.11–1.73.     

Effects of dietary lipid levels on growth, nutrient utilization, and nitrogen and carbon balances in shi drum (Umbrina cirrosa L.)

Shi drum (Umbrina cirrosa L.) is regarded as a promising new candidate for Mediterranean mariculture but specifically formulated feeds are not yet available due to knowledge gaps in its basic nutritional requirements. Therefore, this study was carried out to determine the effects of dietary lipid levels on growth and feed utilization in shi drum (72.6 g average weight). Four isonitrogenic diets differing in dietary lipid levels between 10 and 19% (named 10L, 13L, 16L, and 19L, respectively) were fed to triplicate groups of fish for 8 weeks. Growth was not affected by treatment whereas feed efficiency was significantly deteriorated in fish fed diets containing lipid higher than 13%. Whole body dry matter and lipid contents were significantly higher in fish fed 19L compared with fish fed the 10L, while whole body protein, ash, and total carbon (C) were statistically unaffected by the dietary treatment. A significant increase in feed, lipid, energy, nitrogen (N), and carbon (C) intake was recorded in fish fed 16L and 19L when compared with 10L. Carbon/nitrogen (C/N) ratio was significantly higher in fish fed 19L than 10L. Moreover, the N and C losses significantly increased in fish fed 19L compared with 10L and 13L. It was concluded that high dietary lipid did neither had any protein-sparing effect nor other positive result, and diets for shi drum are not recommended to contain more than 13% lipid.