Combining Ability of Yield Attributed Traits in Rapeseed under Adequate and Low Nitrogen Levels = قدرات الجمع المنسوبة للإنتاج في نبات اللفت تحت مستويات ملائمة و منخفضة للنيتروجين

2015 ◽  
Vol 11 (3) ◽  
pp. 747-760
Author(s):  
Valiollah Rameeh
Keyword(s):  
Combining Ability ◽  
Nitrogen Levels ◽  
Low Nitrogen

scholarly journals Diallelic analysis for lysine and oil contents in maize grains

2009 ◽  
Vol 66 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Leonardo Oliveira Medici ◽  
Salete Aparecida Gaziola ◽  
Vanderlei Aparecido Varisi ◽  
José Antonio Carmezini de Paula ◽  
Renato Rodrigues Ferreira ◽  
...  
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Oil Content ◽  
General Combining Ability ◽  
Lysine Content ◽  
Nitrogen Levels ◽  
N Level ◽  
Complete Series ◽  
Selection For ◽  
Selection Of

Six S5 lines of maize, with differences for lysine and oil contents in grains, were used to carry out a complete series of diallelic crosses. The resulting 15 hybrids were grown in a field at two nitrogen levels (10 and 130 kg N ha-1). The general combining ability (GCA) and specific combining ability (SCA) were obtained by using the method 4, model I of Griffing for grain yield, and grain lysine and oil contents. Significant (p < 0.001) interaction was observed between GCA and N levels for grain yield, indicating the selection of different lines for each N level. This interaction was not significant for lysine content, but there were significant effects of GCA for this trait at both N levels (p < 0.1). Significant effects were not observed for GCA or SCA for oil content, however a positive correlation was observed between lysine and oil contents in the hybrids, in the lines and even in the control cultivars. The results indicate the effectiveness of selection for lysine content, irrespective of N level, in the studied non-opaque maize lines, and the possibility of achieving both high lysine and oil content in grains.

The association of dry-matter yield with nitrogen and soluble-carbohydrate concentration in perennial ryegrass (Lolium perenne L.)

1979 ◽  
Vol 93 (3) ◽  
pp. 657-667 ◽  
Author(s):  
J. Valentine ◽  
A. H. Charles
Keyword(s):  
Nitrogen Concentration ◽  
High Yield ◽  
Soluble Carbohydrate ◽  
Nitrogen Application ◽  
Simple Correlation ◽  
Nitrogen Levels ◽  
Carbohydrate Concentration ◽  
Growth Room ◽  
Selection For ◽  
Low Nitrogen

SUMMARYThe associations between yield, nitrogen and soluble-carbohydrate concentration within S. 23 perennial ryegrass were investigated at three levels of nitrogen application. Controlled growth room conditions were used.The simple correlation between yield and nitrogen concentration was negative at the low rate of nitrogen application, not present at the intermediate rate of nitrogen and positive though not significant at the high rate of nitrogen. Yield and soluble-carbohydrate concentration were only correlated (positively) at the low nitrogen rate.At low nitrogen there were ‘efficient’ genotypes with relatively high yield and low nitrogen concentration. ‘Inefficient’ genotypes had relatively low yields and high nitrogen concentration. The majority of genotypes were neither markedly efficient or inefficient. The efficient genotypes at low nitrogen maintained their yield advantage at higher nitrogen levels with average nitrogen concentration and high numbers of tillers. Inefficient genotypes remained relatively stable in yield, numbers of tillers and nitrogen concentration.Partial correlation indicated an underlying high degree of dependence between yield, nitrogen and soluble-carbohydrate concentration at all nitrogen levels. The association of yield and nitrogen concentration showed a similar trend over nitrogen levels to that obtained using simple correlation. Yield and soluble-carbohydrate concentration were positively related, and nitrogen and soluble-carbohydrate concentration inversely related, when the effects of the remaining attribute were eliminated.Data extracted from Lee et al. (1977) confirmed that yield and nitrogen concentration for varieties under field conditions varied with level of nitrogen application in a similar manner to genotypes in the controlled growth room. The variety (Melle) could be characterized as being particularly efficient.Both sets of results indicate that selection for high yield of nitrogen in herbage can best be achieved through selection for yield alone.

Sulphur metabolism in sheep. IV. The effect of a varied dietary sulphur content on some body fluid sulphate levels and on the utilization of urea-supplemented roughage by sheep

1969 ◽  
Vol 20 (4) ◽  
pp. 759 ◽  
Author(s):  
AC Bray ◽  
JA Hemsley
Keyword(s):  
Body Fluid ◽  
Parotid Saliva ◽  
Crude Fibre ◽  
Nitrogen Levels ◽  
Residual Nitrogen ◽  
Inorganic Sulphate ◽  
Sulphate Sulphur ◽  
Mineral Mixture ◽  
Concentration Changes ◽  
Low Nitrogen

A diet composed of oaten hulls, urea, and mineral mixture was shown to be deficient in sulphur with respect to the nutrition of sheep. Sulphate supplements to the diet increased both crude fibre digestion and nitrogen and sulphur retention. They also increased the concentration of inorganic sulphate in the blood and the levels of total sulphur and total sulphate sulphur in the parotid saliva, but decreased blood urea nitrogen levels and the concentration of residual nitrogen and residual sulphur (protein fraction) in the parotid saliva. The effect of these concentration changes is discussed with particular reference to the feeding of sheep on low sulphur, low nitrogen forages.

Competition between skeleton weed (Chondrila juncea L) and cereals in relation to nitrogen supply

1958 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
LF Myers ◽  
J Lipsett
Keyword(s):  
Crop Yields ◽  
Nitrogen Supply ◽  
Weed Competition ◽  
Nitrogen Application ◽  
High Nitrogen ◽  
Nitrogen Levels ◽  
Grain Nitrogen ◽  
Low Nitrogen ◽  
Yield Of Oats ◽  
Plant Growth Regulating Substances

The effect of skeleton weed competition on the yield of wheat and oats was investigated in seasons when rainfall was plentiful. Nitrogen was found to be the major factor limiting crop yields. In soils with comparable nitrogen-supplying powers, skeleton weed density governed the crop's response to applied nitrogen. Competition between skeleton weed and crop was severe at low nitrogen levels, but minor at the high nitrogen levels achieved either by nitrogen application, or when the crop followed a legume-rich pasture. Competition had its effect early in the crop's growth. Temporary removal of competition, by spraying with plant growth regulating substances (JICPA) at different times, was used to determine when competition was critical, and measure its effects. Skeleton weed reduced nitrogen supply early in the crop's growth, and so depressed yield. An application of 1 lb MCPA per acre in the fallow 54 days before sowing, or 10 days after crop emergence, increased the yield of oats from 710 to 1350 lb grain per acre: a response equal to that from 32 lb nitrogen per acre applied at planting in the same experiment. In each case, the response to spraying at the different times was analogous to the effect of a nitrogen application at these times. Early spraying gave responses in yield; later spraying gave responses in grain nitrogen. The results provide a new estimate of the reduction in crop yield due to skeleton weed.

Exposure to aphids increases alder growth and nitrogen fixation

Botany ◽  
2011 ◽  
Vol 89 (4) ◽  
pp. 255-261 ◽  
Author(s):  
Corinthe Zekveld ◽  
John Markham
Keyword(s):  
Soil Nitrogen ◽  
Plant Nutrition ◽  
Soil Microbes ◽  
Nitrogen Fixing ◽  
Root:Shoot Ratio ◽  
Herbivore Damage ◽  
Resistance Response ◽  
Nitrogen Levels ◽  
Alnus Viridis ◽  
Low Nitrogen

Plants can respond to herbivore damage by mounting a resistance response or by compensating for lost fitness. Both plant nutrition and interactions with soil microbes can affect these responses. It has been shown that resistance responses can occur before plants have been attacked by herbivores. Here we show that a tolerance type of response can occur when plants are exposed to, but not fed on by, herbivores. Alnus viridis (Chaix) DC. spp. crispa (Ait.) Turrill were grown in sealed containers under positive air pressure with either 0.5 mmol·L–1 or 2.0 mmol·L–1 nitrate and either inoculated or not inoculated with Frankia , their nitrogen-fixing symbiont. Plants were then exposed to the genus-specific aphid Prociphilus tessallatus Fitch, which failed to establish feeding colonies. Exposure to aphids, formation of nitrogen-fixing nodules, and elevated soil nitrogen levels all significantly increased plant yield with no interaction among these factors. A combination of high soil nitrogen, nodulation, and exposure to aphids resulted in the lowest plant root:shoot ratio. Plants that were grown with low nitrogen and were exposed to aphids showed increased nitrogen-fixing activity within a day of being exposed. These results provide further evidence to support the observation that plants can respond to cues from other organisms prior to receiving herbivore damage.

The competitive and yielding ability of some sub-tropical pasture species sown alone and in mixtures under intermittent grazing at Samford, south-eastern Queensland

1969 ◽  
Vol 9 (37) ◽  
pp. 181 ◽  
Author(s):  
RJ Jones ◽  
Davies J Griffiths ◽  
RB Waite
Keyword(s):  
White Clover ◽  
Competitive Ability ◽  
Grazing Management ◽  
Tropical Pasture ◽  
Weed Species ◽  
Rhodes Grass ◽  
Nitrogen Levels ◽  
Tropical Legumes ◽  
High Yields ◽  
Low Nitrogen

Eleven introduced tropical grasses were compared in single grass swards and nine of these were compared in mixtures containing two or three grasses. The pastures received 300 lb nitrogen an acre a year as urea and were grazed five times a year. A basal legume mixture of tropical legumes and white clover sown with the grasses failed to persist. There were large differences between the grasses in competitive ability and this varied with time. Samford Rhodes grass, Nandi setaria, and Pangola were the most aggressive, and the Paspalum species-P. plicatulum P. dilatum and P. commersonii the least aggressive. Hyparrhenia hirta, which had done well at low nitrogen levels, failed to compete with weed grasses at the higher nitrogen level used in this study. Rhyncheytrum repens and commercial Rhodes grass were the dominant weed grasses in the establishment year. These rapidly decreased with time, and Digitaria didacola-blue couch, became the dominant weed species. Plots containing Nandi setaria, Samford Rhodes grass, or Pangola, gave the highest yields, and plots containing P. dilatatum the lowest. There was no yield advantage in combining grasses in mixtures-the mixture giving similar or lower yields than the best grass in the mixture grown alone. Under a period of farm grazing the three Rhodes grasses used declined sharply and the proportion of blue couch increased. The high yields from plots dominated by blue couch indicate that, agronomically, this has been a neglected naturalized species. Only Nandi setaria and Pangola were able to compete effectively with blue couch under the 'farm grazing' management imposed.

Variation in ruminal nitrogen levels among some cervidae

1970 ◽  
Vol 48 (6) ◽  
pp. 1437-1442 ◽  
Author(s):  
David R. Klein ◽  
Fritz Schønheyder
Keyword(s):  
Rangifer Tarandus ◽  
Roe Deer ◽  
Capreolus Capreolus ◽  
Odocoileus Hemionus ◽  
Poor Quality ◽  
Nitrogen Levels ◽  
Odocoileus Hemionus Sitkensis ◽  
Successive Generations ◽  
Low Nitrogen ◽  
Apparent Ability

Among black-tailed deer (Odocoileus hemionus sitkensis), roe deer (Capreolus capreolus), and reindeer (Rangifer tarandus), nitrogen levels in the contents of the rumen show consistent patterns of variation. Among deer of each species on the same range during the same season, the animal-derived nitrogen component of the rumen contents decreases as the vegetative nitrogen component increases. This inverse relationship may result from one, or more likely both, of the following causes. (1) The ability of the ruminant to maintain a fairly constant rumen environment to allow for its most efficient function. (2) An adaptability in these deer species to compensate for low nitrogen levels in the forage by recycling of nitrogen through the saliva and further conservation of ruminal nitrogen by recycling it through successive generations of microbial populations. The apparent ability to compensate for variations in forage nitrogen levels is limited when deer are on range of general poor quality or during fall and winter when forage nitrogen levels are reduced.

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