Nodulation and growth of pasture legumes with naturalised soil rhizobia. 3. Lucerne (Medicago sativa L.)

2003 ◽  
Vol 43 (2) ◽  
pp. 135 ◽  
Author(s):  
R. A. Ballard ◽  
B. R. Shepherd ◽  
N. Charman
Keyword(s):  
Sinorhizobium Meliloti ◽  
Plant Density ◽  
South Australia ◽  
Dry Weight ◽  
Most Probable Number ◽  
Multiple Use ◽  
Probable Number ◽  
Shoot Dry Weight ◽  
Pasture Legumes ◽  
Perennial Legume

An assessment was made of the ability of 2 genetically diverse cultivars of lucerne (Trifecta and Sceptre) to nodulate and form effective symbioses with the strains of Sinorhizobium meliloti naturalised in 50 soils. Soils were collected from 42 dryland lucerne pastures and 8 irrigated multiple-use lucerne stands in the south-east of South Australia. The density of lucerne in the paddock, age of the lucerne stand and rhizobial inoculation practice were recorded at sampling. The lucerne swards were on average 5.6 years old (range 1–28) and had a mean plant density of 25 plants/m2 (range 3–66). The lucerne in 39 of the paddocks had been inoculated with rhizobia at sowing.The most probable number of rhizobia (S. meliloti) able to nodulate lucerne was determined for each soil. The most probable number of lucerne rhizobia exceeded 1.0 × 103/g in 23 of the soils. The most probable number of rhizobia in the soil was significantly correlated (r = 0.64) with soil pH. All 13 soils that contained less than 1.0�×�102�rhizobia/g had a pH of less than 6.3.The effectiveness at nitrogen fixation of each population of soil rhizobia was determined in a glasshouse experiment. There was no significant interaction between lucerne cultivar and soil inoculant. Generally, the soil rhizobia were highly effective, with 35 of the 50 soil inoculants producing more than 70% of the shoot dry weight associated with an effective inoculant strain (WSM826). Decreased lucerne shoot dry weights resulting from the remaining soil inoculants were associated with a lower most probable number of rhizobia in the soil, rather than poor symbiotic effectiveness of those rhizobia. This study highlighted the ability of both Trifecta and Sceptre lucernes to form an effective symbiosis with the rhizobia that have naturalised in the soils across a 25 000 km2 region of South Australia. It also showed that soil acidity is detrimental to rhizobial survival even in a perennial legume system and suggests that rhizobia that persist and form nodules in acidic soils should be a focus in the selection of new inoculant strains for lucerne.

Establishment, survival, and herbage production of novel, summer-active perennial pasture legumes in the low-rainfall cropping zone of Western Australia as affected by plant density and cutting frequency

2013 ◽  
Vol 64 (1) ◽  
pp. 71 ◽  
Author(s):  
Lalith D. B. Suriyagoda ◽  
Daniel Real ◽  
Michael Renton ◽  
Hans Lambers ◽  
Megan H. Ryan
Keyword(s):  
Western Australia ◽  
Plant Density ◽  
Dry Weight ◽  
Early Summer ◽  
Annual Rainfall ◽  
Shoot Dry Weight ◽  
Pasture Legumes ◽  
Cutting Frequency ◽  
Perennial Legume ◽  
Perennial Legumes

Herbaceous perennial legumes that can provide forage in the summer–autumn dry period are urgently required in Mediterranean climates to complement annual pastures and the perennial legume lucerne (Medicago sativa). This study evaluated the establishment, survival, and herbage production of tedera (Bituminaria bituminosa var. albomarginata) and Cullen spp. native to Australia. Two experiments were replicated at Buntine (warmer site) and Newdegate (cooler site) in the low-rainfall cropping zone (<350 mm average annual rainfall) of Western Australia from June 2008 to September 2010. In the first experiment, established by transplanting seedlings, survival and herbage production of two accessions each of B. bituminosa and C. australasicum were studied under densities of 1, 2, 4, 8, and 16 plants/m2 with 0, 1, 2, or 3 cuts in summer–autumn in addition to a winter–spring cut. In the second experiment, established from seed, emergence and survival of several accessions of B. bituminosa, C. australasicum, and M. sativa were studied, along with C. pallidum and C. cinereum. In the first experiment, B. bituminosa survived better than C. australasicum (70–80% v. 18–45%), especially at Buntine, but there was little impact of density or cutting frequency on survival. Plant death was highest during summer. Shoot dry weight (DW) accumulation varied greatly with site, year, and plant density. When rainfall was close to average, shoot DW was greater at Newdegate (B. bituminosa ≤7.4 t/ha, C. australasicum ≤4.5 t/ha) than at Buntine (≤2.3 t/ha), and both species produced much of their shoot DW in summer–autumn (e.g. 6 t/ha for B. bituminosa and 3 t/ha for C. australasicum at Newdegate). An early-summer cut reduced the DW that could be harvested later in summer–autumn. In the second experiment, emergence of B. bituminosa was either similar to, or higher than, emergence of the other species, being 43% at Buntine and 44% at Newdegate. Survival of B. bituminosa, compared with M. sativa, was similar at Buntine (13%) and slightly lower at Newdegate (14%). Emergence and survival of Cullen spp. varied among species and accessions, with survival of the best performing accession of C. australasicum (SA4966) similar to that of B. bituminosa and M. sativa at both sites. We conclude that B. bituminosa shows promise as a perennial summer forage for low-rainfall zones, with a density of 8–16 plants/m2 and cutting frequency of 3 cuts/year (i.e. cut twice in summer–autumn), while C. australasicum and C. pallidum warrant further study.

Moulting growth of the Australian giant crab, Pseudocarcinus gigas

2002 ◽  
Vol 53 (5) ◽  
pp. 869 ◽  
Author(s):  
Richard McGarvey ◽  
Andrew H. Levings ◽  
Janet M. Matthews
Keyword(s):  
South Australia ◽  
Growth Increment ◽  
Likelihood Method ◽  
Estimation Methods ◽  
Most Probable Number ◽  
Minimum Length ◽  
Data Sets ◽  
Probable Number ◽  
Commercial Harvest ◽  
Female Data

The growth of Australian giant crabs, Pseudocarcinus gigas, has not been previously studied. A tagging program was undertaken in four Australian states where the species is subject to commercial exploitation. Fishers reported a recapture sample of 1372 females and 383 males from commercial harvest, of which 190 females and 160 males had moulted at least once. Broad-scale modes of growth increment were readily identified and interpreted as 0 , 1 and 2 moults during time at large. Single-moult increments were normally distributed for six of seven data sets. Moult increments were constant with length for males and declined slowly for three of four female data sets. Seasonality of moulting in South Australia was inferred from monthly proportions captured with newly moulted shells. Female moulting peaked strongly in winter (June and July). Males moult in summer (November and December). Intermoult period estimates for P. gigas varied from 3 to 4 years for juvenile males and females (80–120 mm carapace length, CL), with rapid lengthening in time between moulting events to approximately seven years for females and four and a half years for males at legal minimum length of 150 mm CL. New moulting growth estimation methods include a generalization of the anniversary method for estimating intermoult period that uses (rather than rejects) most capture–recapture data and a multiple likelihood method for assigning recaptures to their most probable number of moults during time at large.

scholarly journals The Root Endophytic Fungus Serendipita indica Decreased the Phytotoxicity of Zinc Oxide Nanoparticles to Alfalfa (Medicago sativa L.)

2021 ◽  
Author(s):  
Leila Tabande ◽  
Mozhgan Sepehri ◽  
Jafar Yasrebi ◽  
Mehdi Zarei ◽  
Reza Ghasemi-Fasaei ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Plant Growth ◽  
Zinc Oxide Nanoparticles ◽  
Sinorhizobium Meliloti ◽  
Dry Weight ◽  
Oxide Nanoparticles ◽  
Zno Nps ◽  
Shoot Dry Weight ◽  
Nano Zinc Oxide ◽  
Nano Zinc

Abstract Zinc oxide nanoparticles (ZnO-NPs) are among the most commonly used nano-fertilizers (NF). However, elevated levels of ZnO-NPs in soil may affect plant growth and development due to its potential toxicity when accumulated in large amounts in plant tissues. This research was conducted using an in situ rhizobox system with the aims of evaluating Zinc uptake from nano-zinc oxide amended rhizosphere soil by alfalfa plant and the effect of plant growth promoting microorganisms on alleviating the phytotoxicity of ZnO-NPs. Treatments included microbial inoculations (Sinorhizobium meliloti, Serendipita indica) and different ZnO-NPs concentrations (0, 400 and 800 mg Kg− 1) with three replications. The results indicated that S. indica minimized the phytotoxicity of ZnO-NPs to alfalfa by enhancing growth rate and decreasing Zinc (Zn) translocation from root to shoot. Compared with plants inoculated with S. meliloti, co-inoculation with S. indica increased the shoot dry weight by 18.33% and 8.05% at 400 and 800 mg Kg− 1ZnO-NPs. However, at the highest level of ZnO-NPs (800 mg kg− 1), root inoculation of S. indica and S. indica + S. meliloti decreased Zn transfer factor by 60.2% and 44.3% compared to S. meliloti, respectively. Furthermore, a distinct relation between tolerance of S. indica-colonized plant to ZnO-NPs and the ability of S. indica in inhibiting or retarding degradation of polyunsaturated lipids through prevention of excess reactive oxygen species formation was observed. Malondialdehyde content of inoculated plants with S. indica either alone or in combination with S. meliloti was significantly lower than non-inoculated plants (p < 0.01). Zn-induced oxidative stress was mitigated by S. indica through enhanced activities of catalase and peroxidase enzymes. The findings of the present study indicate the potential use of endophytes fungus S. indica for ensuring food safety and security, and human health in heavy metal–polluted soil by reducing the phytoavailability of heavy metals in the aerial parts of the host plants.

scholarly journals Evidence for Microbial Fe(III) Reduction in Anoxic, Mining-Impacted Lake Sediments (Lake Coeur d'Alene, Idaho)

2000 ◽  
Vol 66 (1) ◽  
pp. 154-162 ◽  
Author(s):  
David E. Cummings ◽  
Anthony W. March ◽  
Benjamin Bostick ◽  
Stefan Spring ◽  
Frank Caccavo ◽  
...  
Keyword(s):  
Iron Reduction ◽  
Dry Weight ◽  
Most Probable Number ◽  
Probable Number ◽  
Coeur D'alene ◽  
Reduction Of Iron ◽  
Study Support ◽  
Reducing Bacteria ◽  
Microbiological Data

ABSTRACT Mining-impacted sediments of Lake Coeur d'Alene, Idaho, contain more than 10% metals on a dry weight basis, approximately 80% of which is iron. Since iron (hydr)oxides adsorb toxic, ore-associated elements, such as arsenic, iron (hydr)oxide reduction may in part control the mobility and bioavailability of these elements. Geochemical and microbiological data were collected to examine the ecological role of dissimilatory Fe(III)-reducing bacteria in this habitat. The concentration of mild-acid-extractable Fe(II) increased with sediment depth up to 50 g kg−1, suggesting that iron reduction has occurred recently. The maximum concentrations of dissolved Fe(II) in interstitial water (41 mg liter−1) occurred 10 to 15 cm beneath the sediment-water interface, suggesting that sulfidogenesis may not be the predominant terminal electron-accepting process in this environment and that dissolved Fe(II) arises from biological reductive dissolution of iron (hydr)oxides. The concentration of sedimentary magnetite (Fe3O4), a common product of bacterial Fe(III) hydroxide reduction, was as much as 15.5 g kg−1. Most-probable-number enrichment cultures revealed that the mean density of Fe(III)-reducing bacteria was 8.3 × 105 cells g (dry weight) of sediment−1. Two new strains of dissimilatory Fe(III)-reducing bacteria were isolated from surface sediments. Collectively, the results of this study support the hypothesis that dissimilatory reduction of iron has been and continues to be an important biogeochemical process in the environment examined.

Adaptation of Lupinus angustifolius L. and L. pilosus Murr. to calcareous soils

1999 ◽  
Vol 50 (6) ◽  
pp. 1027 ◽  
Author(s):  
J. D. Brand ◽  
C. Tang ◽  
A. J. Rathjen
Keyword(s):  
Calcareous Soils ◽  
South Australia ◽  
Clay Content ◽  
Dry Weight ◽  
Lupinus Angustifolius ◽  
Nutrient Concentrations ◽  
Carbonate Content ◽  
Soil Factors ◽  
Shoot Dry Weight ◽  
Caco3 Content

Current varieties of narrow-leafed lupin (Lupin angustifolius L.) are poorly adapted to alkaline and calcareous soils found commonly throughout the south-estern Australian cropping zone. Apot experiment compared the growth of Lupinus angustifolius cv. Gungurru with L. pilosus P20954 in a range of soils collected throughout South Australia. The soils displayed a range of texture (clay, 3–82%), pH (1:5 soil:H2O, 7·0–9·6), and calcium carbonate content (CaCO3, 0–47%). Potting mix (pH 5·8) was used as the control. The plants were grown for 7 weeks with weekly measurements of chlorosis score and leaf number. At harvest, dry weights were recorded and the youngest fully expanded leaves were analysed for nutrient concentrations. The line P20954 grew much better in all the soils than Gungurru in terms of plant dry weight relative to the control soil, this being particularly evident in the calcareous soils. Chlorosis score correlated highly with shoot dry weight for Gungurru, but not for P20954. The main soil factor contributing to the chlorosis score of Gungurru was CaCO3 content, whereas none of the soil factors significantly affected P20954, although in Weeks 2 and 3 chlorosis score correlated with CaCO3 content. The dry weight of Gungurru was affected by a combination of factors including clay content, pH, and CaCO3 content, whereas the dry weight of P20954 was affected by most of the soil factors measured. The dry weight of P20954 was positively correlated with aluminium and magnesium concentrations. Concentrations of all nutrients were above critical levels for both genotypes grown in all soils. The results indicate that L. pilosus has the potential to be grown in areas where current varieties of L. angustifolius are poorly adapted.

Characterization and Identification of Numerically Abundant Culturable Bacteria from the Anoxic Bulk Soil of Rice Paddy Microcosms

1999 ◽  
Vol 65 (11) ◽  
pp. 5042-5049 ◽  
Author(s):  
Kuk-Jeong Chin ◽  
Dittmar Hahn ◽  
Ulf Hengstmann ◽  
Werner Liesack ◽  
Peter H. Janssen
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Dry Weight ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Most Probable Number ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Probable Number ◽  
Clostridial Cluster

ABSTRACT Most-probable-number (liquid serial dilution culture) counts were obtained for polysaccharolytic and saccharolytic fermenting bacteria in the anoxic bulk soil of flooded microcosms containing rice plants. The highest viable counts (up to 2.5 × 108 cells per g [dry weight] of soil) were obtained by using xylan, pectin, or a mixture of seven mono- and disaccharides as the growth substrate. The total cell count for the soil, as determined by using 4′,6-diamidino-2-phenylindole staining, was 4.8 × 108cells per g (dry weight) of soil. The nine strains isolated from the terminal positive tubes in counting experiments which yielded culturable populations that were equivalent to about 5% or more of the total microscopic count population belonged to the divisionVerrucomicrobia, theCytophaga-Flavobacterium-Bacteroides division, clostridial cluster XIVa, clostridial cluster IX, Bacillus spp., and the class Actinobacteria. Isolates originating from the terminal positive tubes of liquid dilution series can be expected to be representatives of species whose populations in the soil are large. None of the isolates had 16S rRNA gene sequences identical to 16S rRNA gene sequences of previously described species for which data are available. Eight of the nine strains isolated fermented sugars to acetate and propionate (and some also fermented sugars to succinate). The closest relatives of these strains (except for the two strains of actinobacteria) were as-yet-uncultivated bacteria detected in the same soil sample by cloning PCR-amplified 16S rRNA genes (U. Hengstmann, K.-J. Chin, P. H. Janssen, and W. Liesack, Appl. Environ. Microbiol. 65:5050–5058, 1999). Twelve other isolates, which originated from most-probable-number counting series indicating that the culturable populations were smaller, were less closely related to cloned 16S rRNA genes.

scholarly journals Simulated mesotrione drift followed by glyphosate, imazethapyr, bentazon or glyphosate plus chlorimuron in soybean

2009 ◽  
Vol 89 (2) ◽  
pp. 265-272
Author(s):  
L. R. Brown ◽  
D. E. Robinson ◽  
K. Chandler ◽  
C. J. Swanton ◽  
R. E. Nurse ◽  
...  
Keyword(s):  
Glycine Max ◽  
Key Words ◽  
Plant Height ◽  
Seed Yield ◽  
Plant Density ◽  
Dry Weight ◽  
Shoot Dry Weight ◽  
Glycine Max L ◽  
Herbicide Drift

There have been anecdotal accounts of increased crop sensitivity due to herbicide drift followed by an in-crop herbicide. An experiment was conducted from 2005 to 2007 at Elora, Ridgetown, and Woodstock, Ontario, to determine the effects of simulated mesotrione drift followed by in-crop applications of glyphosate, imazethapyr, bentazon and glyphosate plus chlorimuron on glyphosate-resistant soybean [Glycine max (L.) Merr.] visual injury, plant height, plant density, shoot dry weight, and seed yield. As the rate of simulated mesotrione drift increased, there was an increase in soybean injury and a decrease in shoot dry weight, height, and yield. Simulated mesotrione drift followed by bentazon resulted in synergistic responses in injury shortly after application in some environments. This increase in injury was transient, with no synergistic responses in density, shoot dry weight, and yield. In contrast, antagonistic responses were observed when glyphosate, imazethapyr, or glyphosate plus chlorimuron were applied after simulated mesotrione drift in some environments. Further research is required to develop a better understanding of the interactions of drift followed by the application of an in-crop herbicide. Key words: Bentazon, chlorimuron, glyphosate, imazethapyr, mesotrione, synergism

Characterisation of dry and mucoid colonies isolated from Australian rhizobial inoculant strains for Medicago species

2005 ◽  
Vol 45 (3) ◽  
pp. 151 ◽  
Author(s):  
A. McInnes ◽  
P. Holford ◽  
J. E. Thies
Keyword(s):  
Nitrogen Fixation ◽  
Sinorhizobium Meliloti ◽  
Dry Weight ◽  
Sequence Element ◽  
Shoot Dry Weight ◽  
Single Colony ◽  
Agar Media ◽  
Fixation Capacity ◽  
Medicago Species ◽  
K Antigen

The presence of dry and mucoid colonies in cultures of rhizobial strains used in the production of commercial Australian inoculants is of concern for quality assurance because of the possibility of altered capacity for nodulation and nitrogen fixation by the different colony types. In this study, single colony isolates obtained from dry and mucoid colonies present in commercial cultures of Sinorhizobium meliloti were investigated to identify stability in culture, genetic identity and changes in exopolysaccharide (EPS) production, nodulation and nitrogen fixation. The 2 strains studied were WSM688 and WSM826 (Australian inoculant strains for annual and perennial medics, respectively), both of which produced only mucoid colonies on agar media when originally isolated from nodules. Dry and mucoid single colony isolates from the ‘mother cultures’ of the 2 strains exhibited stable colony phenotypes during successive subculturing in our laboratory and were shown to be most closely related to S. meliloti using 16S rRNA partial sequencing. All isolates produced at least 1 of 3 exopolysaccharides (succinoglycan, EPS II and K antigen) that are required for successful nodulation of Medicago species by S. meliloti strains, as indicated by nodulation of host legumes. Strain WSM826 isolates probably produce succinoglycan, as shown by similarity to the succinoglycan-producing strain Rm1021 in a calcofluor binding assay. In contrast to published work, there was no evidence that loss of mucoidy in dry colony isolates of either strain was associated with the presence of an insertion sequence element in the expR gene that inhibits EPS II production. For strain WSM688, dry and mucoid isolates were identical by PCR fingerprinting and showed a similar capacity to nodulate and fix nitrogen with the target host legume M. truncatula in glasshouse tests. In contrast, strain WSM826 mucoid isolates produced PCR fingerprints that were different from each other and from the WSM826 dry colony isolates. Dry and mucoid colonies may have arisen from substantial genetic change or through contamination of cultures by other S. meliloti strains. One WSM826 mucoid isolate (826-3) produced significantly lower shoot dry weight when inoculated onto both the target host M. sativa and non-target host M. truncatula, even though the capacity to nodulate both hosts was retained. This suggests that this isolate was affected in its nitrogen fixation capacity. Further research is required to identify the origin and extent of colony variation in commercial S. meliloti cultures.

scholarly journals Peanut Yield Potential as Influenced by Cropping System and Plant Density

1996 ◽  
Vol 23 (2) ◽  
pp. 129-133
Author(s):  
P. E. Igbokwe ◽  
N. V. K. Nkongolo
Keyword(s):  
Seed Weight ◽  
Plant Density ◽  
Cropping System ◽  
Dry Weight ◽  
Yield Potential ◽  
Plant Spacing ◽  
Seed Number ◽  
Vetiveria Zizanioides ◽  
Shoot Dry Weight ◽  
Pod Number

Abstract This study was conducted on a Memphis silt loam at Alcorn State University in 1992 and 1993 and investigated row-intercropping as a low-input alternative to the conventional cropping system for peanut (Arachis hypogaea L.) production in southwestern Mississippi. Extractable P and exchangeable cations were significantly (P ≤ 0.05) higher for vetiver-peanut row-intercropping in 1992. Extractable S and P were significantly (P ≤ 0.05) higher for vetiver-peanut row-intercropping and conventional peanut monocropping, respectively, in 1993. Plant height, shoot dry weight, the number of yellow nutsedge (Cyperus esculentus L.) per row, insect lesions per leaflet, and rodent diggings per row were significantly (P ≤ 0.05) higher for conventional peanut monocropping than when peanut was intercropped with vetiver grass [Vetiveria zizanioides (L.) Nash]. Peanut pod number, pod weight, seed number, and seed weight also were higher for conventional peanut monocropping. The seed mineral composition generally was not affected by cropping system and plant spacing. Peanut yield was higher for 15.2 cm within-row plant spacing compared to 10.2- and 20.3-cm spacings investigated in this study. Interaction between cropping system and plant spacing was significant for pod number, pod weight, seed number, seed weight, and seed Ca and Fe compositions in 1992, but only significant for seed number, seed weight, and seed Fe and Zn compositions in 1993.

Factors affecting growth and reproduction of Noogoora burr (Xanthium occidentale Bertol.)

1984 ◽  
Vol 35 (2) ◽  
pp. 271 ◽  
Author(s):  
RJ Martin ◽  
JA Carnahan
Keyword(s):  
Plant Density ◽  
Unit Area ◽  
Dry Weight ◽  
Low Light ◽  
Factors Affecting ◽  
Shoot Dry Weight ◽  
High Plant Density ◽  
Low Levels ◽  
Net Assimilation ◽  
Growth And Reproduction

Plant density and availability of light and water significantly affected growth and reproduction of Noogoora burr plants grown in a glasshouse. Burr yield was reduced most by low levels of available water. Low light intensity, low water availability and high plant density reduced net assimilation rates and, in combination, caused the greatest reduction in burr production. Under field conditions the ratio of burr dry weight to total shoot dry weight decreased with increasing plant density. In terms of production per unit area, dry weight of main stems and main stem leaves increased with increasing plant density at the expense of burr dry weight. We conclude that the success of Noogoora burr as a fleece contaminant could be attributed, in part, to: the insensitivity of burr production to variation in soil fertility and length of growing season; the ability to regulate plant density under conditions of limiting light or water; and the ability to regulate plant components so that the efficiency of burr production increases with a decrease in plant density.

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