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Neal W Menzies - One of the best experts on this subject based on the ideXlab platform.

  • The effect of copper toxicity on the growth and morphology of Rhodes grass (Chloris gayana) in solution culture
    2020
    Co-Authors: Anna R. Sheldon, Neal W Menzies
    Abstract:

    A solution culture experiment was conducted to examine the effect of Cu toxicity on Rhodes grass (Chloris gayana), a pasture species used in mine site rehabilitation. The experiment used dilute, solution culture to achieve external nutrient concentrations which were representative of the soil solution, and ion exchange resins to maintain stable concentrations of Cu in solution. Copper toxicity was damaged plant roots, with symptoms ranging from disruption of the root cuticle and reduced root hair proliferation, to severe deformation of root structure. A reduction in root growth was observed at an external Cu concentration of

  • toxicity of cd to signal grass brachiaria decumbens stapf and rhodes grass Chloris gayana kunth
    Plant and Soil, 2010
    Co-Authors: Peter M Kopittke, Pax F C Blamey, Neal W Menzies
    Abstract:

    Given that Cd accumulates within plant tissues to levels that are toxic to animals, it is necessary to understand the role of plants in highly Cd-contaminated systems and their subsequent impact on the health of animals. A solution culture experiment was conducted to elucidate the effects of increasing Cd2+ activity ({Cd2+}) on growth of Rhodes grass (Chloris gayana Kunth.) and signal grass (Brachiaria decumbens Stapf.). The shoot and root fresh mass of both Rhodes grass and signal grass was reduced by 50% at ca. 0.5 µM {Cd2+}. Elevated {Cd2+} resulted in a significant decrease in the tissue Mn concentration for both the shoots and roots, and caused a chlorosis of the veins in the shoots. Root hair growth was prolific even at high {Cd2+}, thus root hair growth appeared to be less sensitive to elevated Cd than was root growth per se. The critical shoot tissue concentrations (50% reduction in growth), 230 µg g−1 for Rhodes grass and 80 µg g−1 for signal grass, exceeded the maximum level of Cd tolerated in the diet of animals (ca. 5 µg g−1). When assessing the risk associated with the revegetation of Cd-contaminated sites with Rhodes grass or signal grass, careful consideration must be given, therefore, to the transfer of toxic concentrations of Cd to grazing animals and through the wider food chain.

  • localization and chemical speciation of pb in roots of signal grass brachiaria decumbens and rhodes grass Chloris gayana
    Environmental Science & Technology, 2008
    Co-Authors: Peter M Kopittke, C J Asher, Pax F C Blamey, G J Auchterlonie, Neal W Menzies
    Abstract:

    Lead (Pb) contamination of soils is of global importance but little is known regarding Pb uptake, localization, or the chemical forms in which Pb is found within plants, or indeed how some plants tolerate elevated Pb in the environment. Two grasses, signal grass (Brachiaria decumbens Stapf) (Pb-resistant) and Rhodes grass (Chloris gayana Kunth) (Pb-sensitive), were grown for 14 d in dilute nutrient solutions before examination of roots using transmission electron microscopy (TEM) to determine the distribution and speciation of Pb in situ. In both grasses, Pb was initially present primarily in the cytoplasm of rhizodermal and cortical cells before being sequestered within vacuoles as the highly insoluble (and presumably nontoxic) chloropyromorphite (Pb5(PO4)3Cl). In signal grass, Pb also accumulated within membranous structures (perhaps the Golgi apparatus), prior to apoplastic sequestration as chloropyromorphite. These findings suggest that the ability of signal grass to sequester insoluble Pb in the cell...

  • toxic effects of pb2 on the growth and mineral nutrition of signal grass brachiaria decumbens and rhodes grass Chloris gayana
    Plant and Soil, 2007
    Co-Authors: Peter M Kopittke, C J Asher, F P C Blamey, Neal W Menzies
    Abstract:

    Although grasses are commonly used to revegetate sites contaminated with lead (Pb), little is known regarding the Pb-tolerance of many of these species. Using dilute solution culture to mimic the soil solution, the growth of signal grass (Brachiaria decumbens Stapf cv. Basilisk) and Rhodes grass (Chloris gayana Kunth cv. Pioneer) was related to the mean activity of Pb2+ {Pb2+} in solution. There was a 50% reduction in fresh mass of signal grass shoots at 5 μM {Pb2+} and at 3 μM {Pb2+} for the roots. Rhodes grass was considerably more sensitive to Pb in solution, with shoot and root fresh mass being reduced by 50% at 0.5 μM {Pb2+}. The higher tolerance of signal grass to Pb appeared to result from the internal detoxification of Pb, rather than from the exclusion of Pb from the root. At toxic {Pb2+}, an interveinal chlorosis developed in the shoots of signal grass (possibly a Pb-induced Mn deficiency), whilst in Rhodes grass, Pb2+ caused a bending of the root tips and the formation of a swelling immediately behind some of the root apices. Root hair growth did not appear to be reduced by Pb2+ in solution, being prolific at all {Pb2+} in both species.

  • brachiaria decumbens and rhodes grass Chloris gayana
    2007
    Co-Authors: Peter M Kopittke, C J Asher, F P C Blamey, Neal W Menzies
    Abstract:

    Although grasses are commonly used to revegetate sites contaminated with lead (Pb), little is known regarding the Pb-tolerance of many of these species. Using dilute solution culture to mimic the soil solution, the growth of signal grass (Brachiaria decumbens Stapf cv. Basilisk) and Rhodes grass (Chloris gayana Kunth cv. Pioneer) was related to the mean activity of Pb 2+ {Pb 2+ } in solution. There was a 50% reduction in fresh mass of signal grass shoots at 5 µM {Pb 2+ } and at 3 µM {Pb 2+ } for the roots. Rhodes grass was considerably more sensitive to Pb in solution, with shoot and root fresh mass being reduced by 50% at 0.5 µM {Pb 2+ }. The higher tolerance of signal grass to Pb appeared to result from the internal detoxification of Pb, rather than from the exclusion of Pb from the root. At toxic {Pb 2+ }, an interveinal chlorosis developed in the shoots of signal grass (possibly a Pb-induced Mn deficiency), whilst in Rhodes grass, Pb 2+ caused a bending of the root tips and the formation of a swelling immediately behind some of the root apices. Root hair growth did not appear to be reduced by Pb 2+ in solution, being prolific at all {Pb 2+ } in both species.

Peter M Kopittke - One of the best experts on this subject based on the ideXlab platform.

  • toxicity of cd to signal grass brachiaria decumbens stapf and rhodes grass Chloris gayana kunth
    Plant and Soil, 2010
    Co-Authors: Peter M Kopittke, Pax F C Blamey, Neal W Menzies
    Abstract:

    Given that Cd accumulates within plant tissues to levels that are toxic to animals, it is necessary to understand the role of plants in highly Cd-contaminated systems and their subsequent impact on the health of animals. A solution culture experiment was conducted to elucidate the effects of increasing Cd2+ activity ({Cd2+}) on growth of Rhodes grass (Chloris gayana Kunth.) and signal grass (Brachiaria decumbens Stapf.). The shoot and root fresh mass of both Rhodes grass and signal grass was reduced by 50% at ca. 0.5 µM {Cd2+}. Elevated {Cd2+} resulted in a significant decrease in the tissue Mn concentration for both the shoots and roots, and caused a chlorosis of the veins in the shoots. Root hair growth was prolific even at high {Cd2+}, thus root hair growth appeared to be less sensitive to elevated Cd than was root growth per se. The critical shoot tissue concentrations (50% reduction in growth), 230 µg g−1 for Rhodes grass and 80 µg g−1 for signal grass, exceeded the maximum level of Cd tolerated in the diet of animals (ca. 5 µg g−1). When assessing the risk associated with the revegetation of Cd-contaminated sites with Rhodes grass or signal grass, careful consideration must be given, therefore, to the transfer of toxic concentrations of Cd to grazing animals and through the wider food chain.

  • localization and chemical speciation of pb in roots of signal grass brachiaria decumbens and rhodes grass Chloris gayana
    Environmental Science & Technology, 2008
    Co-Authors: Peter M Kopittke, C J Asher, Pax F C Blamey, G J Auchterlonie, Neal W Menzies
    Abstract:

    Lead (Pb) contamination of soils is of global importance but little is known regarding Pb uptake, localization, or the chemical forms in which Pb is found within plants, or indeed how some plants tolerate elevated Pb in the environment. Two grasses, signal grass (Brachiaria decumbens Stapf) (Pb-resistant) and Rhodes grass (Chloris gayana Kunth) (Pb-sensitive), were grown for 14 d in dilute nutrient solutions before examination of roots using transmission electron microscopy (TEM) to determine the distribution and speciation of Pb in situ. In both grasses, Pb was initially present primarily in the cytoplasm of rhizodermal and cortical cells before being sequestered within vacuoles as the highly insoluble (and presumably nontoxic) chloropyromorphite (Pb5(PO4)3Cl). In signal grass, Pb also accumulated within membranous structures (perhaps the Golgi apparatus), prior to apoplastic sequestration as chloropyromorphite. These findings suggest that the ability of signal grass to sequester insoluble Pb in the cell...

  • toxic effects of pb2 on the growth and mineral nutrition of signal grass brachiaria decumbens and rhodes grass Chloris gayana
    Plant and Soil, 2007
    Co-Authors: Peter M Kopittke, C J Asher, F P C Blamey, Neal W Menzies
    Abstract:

    Although grasses are commonly used to revegetate sites contaminated with lead (Pb), little is known regarding the Pb-tolerance of many of these species. Using dilute solution culture to mimic the soil solution, the growth of signal grass (Brachiaria decumbens Stapf cv. Basilisk) and Rhodes grass (Chloris gayana Kunth cv. Pioneer) was related to the mean activity of Pb2+ {Pb2+} in solution. There was a 50% reduction in fresh mass of signal grass shoots at 5 μM {Pb2+} and at 3 μM {Pb2+} for the roots. Rhodes grass was considerably more sensitive to Pb in solution, with shoot and root fresh mass being reduced by 50% at 0.5 μM {Pb2+}. The higher tolerance of signal grass to Pb appeared to result from the internal detoxification of Pb, rather than from the exclusion of Pb from the root. At toxic {Pb2+}, an interveinal chlorosis developed in the shoots of signal grass (possibly a Pb-induced Mn deficiency), whilst in Rhodes grass, Pb2+ caused a bending of the root tips and the formation of a swelling immediately behind some of the root apices. Root hair growth did not appear to be reduced by Pb2+ in solution, being prolific at all {Pb2+} in both species.

  • brachiaria decumbens and rhodes grass Chloris gayana
    2007
    Co-Authors: Peter M Kopittke, C J Asher, F P C Blamey, Neal W Menzies
    Abstract:

    Although grasses are commonly used to revegetate sites contaminated with lead (Pb), little is known regarding the Pb-tolerance of many of these species. Using dilute solution culture to mimic the soil solution, the growth of signal grass (Brachiaria decumbens Stapf cv. Basilisk) and Rhodes grass (Chloris gayana Kunth cv. Pioneer) was related to the mean activity of Pb 2+ {Pb 2+ } in solution. There was a 50% reduction in fresh mass of signal grass shoots at 5 µM {Pb 2+ } and at 3 µM {Pb 2+ } for the roots. Rhodes grass was considerably more sensitive to Pb in solution, with shoot and root fresh mass being reduced by 50% at 0.5 µM {Pb 2+ }. The higher tolerance of signal grass to Pb appeared to result from the internal detoxification of Pb, rather than from the exclusion of Pb from the root. At toxic {Pb 2+ }, an interveinal chlorosis developed in the shoots of signal grass (possibly a Pb-induced Mn deficiency), whilst in Rhodes grass, Pb 2+ caused a bending of the root tips and the formation of a swelling immediately behind some of the root apices. Root hair growth did not appear to be reduced by Pb 2+ in solution, being prolific at all {Pb 2+ } in both species.

E. N. Njoka - One of the best experts on this subject based on the ideXlab platform.

Atsushi Tsunekawa - One of the best experts on this subject based on the ideXlab platform.

  • Effects of different forms of white lupin (Lupinus albus) grain supplementation on feed intake, digestibility, growth performance and carcass characteristics of Washera sheep fed Rhodes grass (Chloris gayana) hay-based diets
    Tropical Animal Health and Production, 2015
    Co-Authors: Gebru Tefera, Firew Tegegne, Yeshambel Mekuriaw, Solomon Melaku, Atsushi Tsunekawa
    Abstract:

    Protein is the major limiting nutrient in feeding ruminants especially in dryland areas. Thus, looking for locally available protein sources such as white lupin ( Lupinus albus ) grain is commendable. The objective of this experiment was to determine effects of supplementation of different forms of white lupin grain (WLG) on feed and nutrient intake, digestibility, growth and carcass characteristics. Twenty-five yearling male Washera sheep with initial body weight (BW) of 16.26 ± 1.41 kg (mean ± SD) were used. Animals were blocked into five based on their initial BW and were randomly assigned to one of the following five dietary treatments: Rhodes grass ( Chloris gayana ) hay (RGH) alone (T_1) or supplemented with 300 g (on dry matter (DM) basis) raw WLG (T_2) or raw soaked and dehulled WLG (T_3) or roasted WLG (T_4) or raw soaked WLG (T_5). Supplementation with WLG significantly improved total DM and nutrient intake ( P  

  • effects of different forms of white lupin lupinus albus grain supplementation on feed intake digestibility growth performance and carcass characteristics of washera sheep fed rhodes grass Chloris gayana hay based diets
    Tropical Animal Health and Production, 2015
    Co-Authors: Gebru Tefera, Firew Tegegne, Yeshambel Mekuriaw, Solomon Melaku, Atsushi Tsunekawa
    Abstract:

    Protein is the major limiting nutrient in feeding ruminants especially in dryland areas. Thus, looking for locally available protein sources such as white lupin (Lupinus albus) grain is commendable. The objective of this experiment was to determine effects of supplementation of different forms of white lupin grain (WLG) on feed and nutrient intake, digestibility, growth and carcass characteristics. Twenty-five yearling male Washera sheep with initial body weight (BW) of 16.26 ± 1.41 kg (mean ± SD) were used. Animals were blocked into five based on their initial BW and were randomly assigned to one of the following five dietary treatments: Rhodes grass (Chloris gayana) hay (RGH) alone (T1) or supplemented with 300 g (on dry matter (DM) basis) raw WLG (T2) or raw soaked and dehulled WLG (T3) or roasted WLG (T4) or raw soaked WLG (T5). Supplementation with WLG significantly improved total DM and nutrient intake (P 0.05). It is concluded that roasting white lupin grain can lead to a better feed and nutrient intake and consequently better carcass quality. White lupin grain can be recommended not only for maintenance but also for optimum performance of ruminants.

J. O. Ondiek - One of the best experts on this subject based on the ideXlab platform.