Comparative levels of dimethyltryptamine- and tyramine-related alkaloid toxins in Australian cultivars and some wild populations of Phalaris aquatica

2005 ◽  
Vol 56 (12) ◽  
pp. 1395 ◽  
Author(s):  
R. A. Culvenor ◽  
K. F. M. Reed ◽  
S. E. McDonald

Phalaris (Phalaris aquatica L.) is a temperate perennial grass which occasionally causes toxicity in livestock. Immunoassays (ELISAs) were used to measure the level of the dimethyltryptamine and related alkaloid group (TRYP) and the tyramine-related group of alkaloids (TYR) in cultivars, breeding populations and wild accessions of phalaris. Herbage was sampled from grazed swards or spaced plants at several sites and times. Component alkaloids in 4 cultivars were also determined by thin-layer chromatography (TLC). Levels of TYR were higher than TRYP at all times of sampling. Alkaloid levels varied widely with site and sampling time, green herbage sampled in autumn being much higher than herbage sampled from July onwards. Plants sampled in autumn usually appeared moisture stressed and this may have been 1 factor causing high alkaloid levels in autumn. Comparative levels of TRYP in older cultivars agreed with published information. Two semi-winter dormant cultivars, Australian and the new and closely-related Australian II, were both higher than other cultivars in TRYP (maximum levels 18–20 mg/100 g fresh weight) but similar to most in TYR. Among winter-active cultivars, Holdfast and Sirolan were very low in TRYP (maximum levels <0.5 mg/100 g fresh weight) but Holdfast was the highest of all cultivars in TYR. While we argue on the basis of the TLC analyses and from previous work that the bulk of TYR in phalaris cultivars is N-methyltyramine, Holdfast was an exception in having one-third of its TYR as the less toxic hordenine in TLC analyses. Other new cultivars, Landmaster and Atlas PG, and breeding populations being developed as potential cultivars for acid soils or with improved grazing tolerance were generally higher than Holdfast and Sirolan, and similar to Sirosa, in TRYP (maximum levels 1–5 mg/100 g fresh weight). All were less than Holdfast in TYR. Two sets of wild accessions, 1 of which is being used in the development of a cultivar for the North-West Slopes of NSW, were relatively high in TYR alkaloids.

2009 ◽  
Vol 60 (11) ◽  
pp. 1097 ◽  
Author(s):  
R. A. Culvenor ◽  
S. P. Boschma ◽  
K. F. M. Reed

Forage grass cultivars must have adequate grazing tolerance for use in the grazing systems for which they are intended. Response to 2 cycles of selection for persistence under heavy grazing pressure was examined in 3 winter-active breeding populations of the productive perennial grass, phalaris (Phalaris aquatica L.), from 2000 to 2003, at Bulart in western Victoria and Rye Park on the Southern Tablelands and Tamworth on the North-West Slopes of New South Wales. There was one continuously grazed and one rotationally grazed set of plots at Bulart to examine the effect of grazing management. All sites were affected by drought in later years but drought stress was most severe at Tamworth. A strongly positive linear response to selection was observed in an analysis of persistence measured as frequency of phalaris plant base across the 3 sites (excluding the rotational treatment at Bulart), but response interacted with site. By 2003, linear response averaged 14% frequency units or 34–40% proportional response per cycle at Rye Park and the continuously grazed plots at Bulart, sites that were environmentally suited to survival of phalaris. In contrast, response to selection was absent or slightly negative at Tamworth where conditions were drier and hotter. Populations responded similarly in analyses across all 3 sites but 1 population was less responsive when analyses were restricted to Bulart and Rye Park. Herbage mass measurements in 2001 at Bulart and 2002 at Rye Park indicated positive responses to selection, which were increasingly linked to frequency over time. Rotationally grazed plots at Bulart displayed higher frequency than continuously grazed plots after 3 years of grazing. The experiment showed that grazing tolerance was a heritable trait in the populations tested when environmental constraints were not limiting and that useful improvements in persistence had been obtained compared with existing cultivars.


Author(s):  
Е. V. Dubina-Chekhovich ◽  
L. P. Evstratova ◽  
O. N. Bakhmet

It was determined during the study that a technogenic succession of perennial gramineous motley grass phytocenosis took place on reclaimed agricultural lands near mining company. The goal of a study was to estimate the shift in botanical composition and productivity of perennial agrophytocenosis on reclaimed fallow soils under aerial technogenic influence in Karelia. Over the last three years perennial gramineous herbs (Bromopsis inermis L., Phleum pratense L.) and motley grass (Urtica dioica L., Anthriscus sylvestris L., Chamaenerion angustifolium L.) are dominant in phyto-association. As we move away from mining location (100, 200, 300 meters) a gradual natural shift in vegetation takes place. The quantity of gramineous herbs decreases (from 77,8 to 42,9%) and the quantity of motley grass increases (from 21,2 to 56,8%) as compared to a control plot (16,5 and 82,9% accordingly). Low level of rainfall at the first half of summer, which is normal for Karelian climate, presence of polluting substances in soil and on surface caused substantial decline in growth of valuable fodder such as Bromopsis inermis (linear indicator 20,7 – 31,8 centimeters) as compared to background conditions (40,2 centimeters). Also, the mentioned above circumstances caused increase of total yield of perennial grass (13,2 – 16,4 – 22,0 tons per hectare; background – 28,0 tons per hectare) as we move away from mining location.


2006 ◽  
Vol 12 ◽  
pp. 89-92
Author(s):  
Richard Culvenor ◽  
Suzanne Boschma ◽  
Kevin Reed

Phalaris (Phalaris aquatica L.) is a perennial grass of Mediterranean origin used widely by the sheep and cattle industries of south-eastern Australia. Winter-active cultivars released since the 1970's have the potential for higher herbage productivity than the earlier, semi-winter dormant cultivars but have been reported to be less persistent under sub-optimal grazing management and soil conditions. To improve genetic potential for persistence in winter-active phalaris, a program of recurrent selection was conducted by subjecting three populations of half-sib families to two cycles of selection for persistence under heavy, largely continuous grazing pressure. Cycle 2 progeny families and bulked seedlots of each generation were grown in separate grazed plot trials in Western Victoria and the Southern Tablelands and North-West Slopes of New South Wales from 1999-2003 to assess response to selection. Positive linear response to selection was observed in all populations at the Western Victorian and Southern Tablelands sites. Response to selection was absent and persistence was very low under higher temperature and drought stress on the North-West Slopes. This high level of genotype × environment interaction for persistence was also observed among final generation families. Families with better persistence than current winteractive cultivars at the two southern sites were identified in each population and a new cultivar is being formed from the parents.


2020 ◽  
pp. 82-102
Author(s):  
Ilya E. Smelansky ◽  
◽  
Andrey A. Tomilenko ◽  
Anna N. Barashkova ◽  
Alexander A. Yakovlev ◽  
...  

In May and June 2018 and June 2019 we surveyed breeding populations of large raptors (principally Golden Eagle Aquila chrysaetos, Eastern Imperial Eagle Aquila heliaca, Steppe Eagle Aquila nipalensis, Long-Legged Buzzard Buteo rufinus, Saker Falcon Falco cherrug and Eagle Owl Bubo bubo) in the north-west of the Ustyurt Plateau within the boundaries of the Atyrau Province, Kazakhstan. The area surveyed was ca. 1000 km2 represented the wider area of 3400 km2. Total 12 species of birds of prey were recorded and 8 of them considered as large raptors. Golden Eagle was found nesting on the Donyztau escarpment, 4 breeding territories were recorded and 3 of them successful; nesting density is estimated at about 5.0–6.7 pairs per 100 km of cliffs, the distance between neighboring pairs was ca. 6 km. Imperial Eagle: 5 breeding territories found on the Donyztau and Zheltau escarpments, 4 of them successful; average nesting density is 3.8 pairs per 100 km of cliffs. Steppe Eagle: 14 breeding territories (25 nests) revealed, among them 6 are successful (1–2 nestlings) and on other 3 breeding was failed; average nesting density is estimated at 1.3 pairs per 100 km2. Average distance between neighboring active nests is 2.5 km in Sholkara hill ridge but the distance between successful nests here is much bigger and makes about 13 km. Long-Legged Buzzard: 13 breeding territories (30 nests) found, of which 11 territories were actually occupied and 8 of them had successful breeding. Saker Falcon is found nesting on Donyztau escarpment: 4 breeding territories, including 3 successful; the average nesting density is 6.7 pairs per 100 km of cliffs. Eagle Owl recorded throughout the surveyed area; 11 breeding territories revealed, the average nesting density is 7 breeding territories per 100 km of cliffs and steep slopes. Two other species, Short-toad Eagle and Cinereous Vulture, recorded only occasionally, nesting in the area is not found. In general, our findings demonstrate the area is important for conserving several species of large raptors in the Atyrau Province.


2005 ◽  
Vol 56 (7) ◽  
pp. 731 ◽  
Author(s):  
R. A. Culvenor ◽  
S. P. Boschma

The survival of available cultivars of introduced temperate perennial grasses has been less than adequate under grazing on the North-West Slopes of New South Wales. A wide range of germplasm of the Mediterranean perennial grass, phalaris (Phalaris aquatica L.), was assessed for persistence, seedling vigour, winter yield potential, time of reproductive development, and summer dormancy in grazed swards at 3 sites (Manilla, Tamworth, Purlewaugh) from 1998 to 2001. The aim was to understand population characteristics that influence persistence in this environment and to identify persistent populations. Good establishment was achieved after above-average winter–spring rainfall in 1998. Persistence was high during the first year of grazing (1999) but declined under lower rainfall during 2000 at the Manilla and Tamworth sites. By 2001, a wide range in persistence had developed at these 2 sites. A group of wild populations, mainly from North Africa, was identified as being more persistent at both sites than any available cultivar. Two early cultivars, Sirocco and CPI 19305, were also relatively persistent. None of the germplasm survived a subsequent severe drought in 2002 at Manilla and Tamworth. Persistence remained high despite higher grazing pressure at the Purlewaugh site until the 2002 drought year, when changes in survival correlated with those at the other sites occurred. Biplot analysis indicated that early reproductive development and high summer dormancy were associated with persistence in both wild and bred populations. High seedling and winter growth potential was less strongly associated with persistence. Wild and bred germplasm from North Africa displayed these characteristics to a marked extent, whereas germplasm from southern Europe and Sardinia did not and was less persistent. A group of wild populations mainly from Morocco was identified as the basis for cultivar development.


1979 ◽  
Vol 19 (101) ◽  
pp. 698 ◽  
Author(s):  
GM Lodge ◽  
EA Roberts

The effects of phosphorus (P), sulphur (S) and stocking rate on the dry matter yield, and chemical and botanical composition of natural pasture were examined from November, 1971 to May, 1976 in a 20 point central composite design. P and S were applied annually at five levels (0, 6, 15, 23, 29 kg P ha-1; 0, 14, 34, 54, 67 kg S ha-1) and the plots were grazed continuously at five stocking rates (2.2, 3.2, 4.8, 6.3, 7.3 dry ewes ha-1). Each of the factors, P, S, and stocking rate affected total dry matter. At 4.8 and 6.3 sheep ha-1 the optimum rate of P was 15 kg ha-1, but at 3.2 sheep ha-1 it increased from 15 kg ha-1 to 23 kg ha-1 over the period. S had little effect on yield at the start and end of the experiment, but in between its effect depending on stocking rate; at 3.2 sheep ha-1 low levels (<I4 kg ha-1) were optimal, but at 4.8 and 6.3 sheep ha-1 very high levels (>54 kg ha-1) were needed. The quantity of green grass and legume was low in winter and was not consistently affected by any of the factors. The level of N in the green grass remained at less than 2%. Over the period of the experiment the basal cover of perennial grass and the frequency of annual legume declined, while the percentage of bare ground and annual grass increased. These changes over time could not be related to any of the factors, except that the percentage of A. ramosa declined at the higher stocking rates. In some years high stocking rate decreased the percentage of A. ramosa and S. variabilis, and increased that of C. truncata, D. linkii, K. phleoides and T. glomeratum. In terms of pasture yield, fertilized perennial grass pastures on the North-West Slopes have potential carrying capacities of at least 4.8 dry sheep ha-1. However, to support this high stocking rate without significantly affecting pasture yield high levels of S, around 54 kg ha-1, and moderate levels of P, around 15 kg ha-1, are required. At this higher stocking rate no major changes in botanical composition occurred.


2014 ◽  
Vol 65 (11) ◽  
pp. 1165 ◽  
Author(s):  
R. A. Culvenor ◽  
R. J. Simpson

Persistence is consistently claimed by Australian farmers as a high priority for perennial grasses in long-term pastures. Phalaris (Phalaris aquatica L.) is a productive perennial grass with proven persistence in south-eastern Australia. Nevertheless, factors that determine the persistence of pasture species in southern Australia related to climate (drought), soil (acidity), grazing pressure, and, importantly, their interaction can reduce persistence of phalaris and other species in various situations. These factors and their interactions are discussed in this review, and strategies to improve persistence with emphasis on plant breeding approaches are considered, with the most durable outcomes achieved when breeding and management options are employed concurrently. Two examples of breeding to improve persistence traits in phalaris are described. A program to improve acid-soil tolerance resulted first in the release of cv. Landmaster, and recently Advanced AT, which is the most aluminium (Al)-tolerant cultivar of phalaris to date. It was bred by recurrent selection on acid soils in a population containing genes from a related, more Al-tolerant species, P. arundinacea. The higher Al tolerance of cv. Advanced AT is of most benefit in more assured establishment on acid soils under variable moisture conditions and confers improved flexibility of sowing date. Cultivar Holdfast GT was bred to address complaints of poor persistence under heavy grazing by cultivars of the highly productive, winter-active type, since high grazing tolerance is needed to achieve profitable returns from developed pastureland. Evidence of good persistence under grazing for cv. Holdfast GT and possible tradeoffs with productivity are discussed. Maintaining high productivity under a predicted higher incidence of drought stress (climate change) and increasing areas of acid soils presents ongoing challenges for persistence in pastures.


Author(s):  
Daryl A. Cornish ◽  
George L. Smit

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.


2014 ◽  
Author(s):  
Roald Amundsen ◽  
Godfred Hansen
Keyword(s):  

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