Selection of hydroxyproline-resistant proline-accumulating mutants of cauliflower. C.R. Deane, M .P. Fuller' & P.J. Dix

A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0 .3 mM solution on each 3 mm diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly affecting shoot regeneration from explants . Thirty one resistant shoots were recovered from more than six thousand explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained from a similar number of non-mutagenised controls . Out of twenty-three resistant shoots which survived subculture, only one showed consistently elevated levels of endogenous proline . During early shoot culture passages, proline levels were 3 .6-4.7 times higher than controls, but this was reduced to 1 .6 times after 10-12 culture passages in the absence of hydroxyproline . Possible reasons for this decline are discussed . Leaf strip assays suggest resistant shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors . These will then be evaluated for any alteration in frost tolerance

Selection of hydroxyproline-resistant proline-accumulating mutants of cauliflower. C.R. Deane, M .P. Fuller' & P.J. Dix

A procedure is described by which hydroxyproline-resistant lines could be selected from regenerating curd tissue of cauliflower. Mutagenesis was by N-nitroso-N-ethylurea, supplied as a drop of 0 .3 mM solution on each 3 mm diameter curd piece. The mutagen generated numerous morphological and pigment mutations without significantly affecting shoot regeneration from explants . Thirty one resistant shoots were recovered from more than six thousand explants mutagenised on regeneration medium supplemented with 3 mM hydroxyproline, while none was obtained from a similar number of non-mutagenised controls . Out of twenty-three resistant shoots which survived subculture, only one showed consistently elevated levels of endogenous proline . During early shoot culture passages, proline levels were 3 .6-4.7 times higher than controls, but this was reduced to 1 .6 times after 10-12 culture passages in the absence of hydroxyproline . Possible reasons for this decline are discussed . Leaf strip assays suggest resistant shoots may be chimeras and current efforts are directed towards regenerating solid mutants from resistant sectors . These will then be evaluated for any alteration in frost tolerance

In vitro strategies for improvement of frost tolerance in cauliflower.

Two in vitro selection strategies were employed in an effort to obtain cauliflower lines with improved cold tolerance

In vitro strategies for improvement of frost tolerance in cauliflower.

Two in vitro selection strategies were employed in an effort to obtain cauliflower lines with improved cold tolerance

Use of butorphanol and diprenorphine to counter respiratory impairment in the immobilised white rhinoceros (Ceratotherium simum)

Opioid-induced immobilisation results in severe respiratory impairment in the white rhinoceros. It has therefore been attempted in the field to reverse this impairment with the use of opioid agonist-antagonists, such as nalorphine, nalbuphine, butorphanol and diprenorphine; however, the efficacy of some of these treatments has yet to be determined. The efficacy of butorphanol, either alone or in combination with diprenorphine both with and without oxygen insufflation, in alleviating opioid-induced respiratory impairment was evaluated. The study was performed in two parts: a boma trial and a field trial. Rhinoceroses were immobilised specifically for the study, according to a strict protocol to minimise confounding variables. A two-way analysis of variance was used to compare the physiological responses of the rhinoceroses to the different treatments and their effects over time. The intravenous administration of butorphanol (at 3.3 mg per mg etorphine) plus diprenorphine (at 0.4 mg per mg etorphine) did not offer any advantage over butorphanol (at 15 mg per mg etorphine) alone with regard to improving PaO2, PaCO2 and respiratory rates in etorphine-immobilised white rhinoceroses. Both butorphanol + diprenorphine + oxygen and butorphanol + oxygen, at the doses used, significantly improved the etorphine-induced hypoxaemia in both boma- and field-immobilised white rhinoceroses. Clinically acceptable oxygenation in field-immobilised white rhinoceroses can be achieved by using either treatment regimen, provided that it is combined with oxygen insufflation

FAPRI 2004 U.S. and World Agricultural Outlook

Crop Production/Industries, Livestock Production/Industries,

FAPRI 2006 U.S. and World Agricultural Outlook

The FAPRI 2006 U.S. and World Agricultural Outlook presents projections of world agricultural production, consumption, and trade under average weather patterns, existing farm policy, and policy commitments under current trade agreements and custom unions. Despite continued high energy prices, world economic growth is expected to remain strong in the coming decade, above 3% per annum. Other major drivers of the 2006 baseline include new bio-energy policies in several large countries, EU sugar policy reform, sanitary and phytosanitary (SPS) shocks in livestock and poultry markets, and movements in the exchange rate.Crop Production/Industries, International Relations/Trade, Livestock Production/Industries,

FAPRI 2005 U.S. and World Agricultural Outlook

Crop Production/Industries, Livestock Production/Industries,

FAPRI 2002 World Agricultural Outlook

Crop Production/Industries, Livestock Production/Industries,

Life path analysis: scaling indicates priming effects of social and habitat factors on dispersal distances

1. Movements of many animals along a life-path can be separated into repetitive ones within home ranges and transitions between home ranges. We sought relationships of social and environmental factors with initiation and distance of transition movements in 114 buzzards Buteo buteo that were marked as nestlings with long-life radio tags. 2. Ex-natal dispersal movements of 51 buzzards in autumn were longer than for 30 later in their first year and than 35 extra-natal movements between home ranges after leaving nest areas. In the second and third springs, distances moved from winter focal points by birds that paired were the same or less than for unpaired birds. No post-nuptial movement exceeded 2 km. 3. Initiation of early ex-natal dispersal was enhanced by presence of many sibs, but also by lack of worm-rich loam soils. Distances travelled were greatest for birds from small broods and with relatively little short grass-feeding habitat near the nest. Later movements were generally enhanced by the absence of loam soils and short grassland, especially with abundance of other buzzards and probable poor feeding habitats (heathland, long grass). 4. Buzzards tended to persist in their first autumn where arable land was abundant, but subsequently showed a strong tendency to move from this habitat. 5. Factors that acted most strongly in ½-km buffers round nests, or round subsequent focal points, usually promoted movement compared with factors acting at a larger scale. Strong relationships between movement distances and environmental characteristics in ½-km buffers, especially during early ex-natal dispersal, suggested that buzzards became primed by these factors to travel far. 6. Movements were also farthest for buzzards that had already moved far from their natal nests, perhaps reflecting genetic predisposition, long-term priming or poor habitat beyond the study area