Changes in the nitrogenous components of maturing rapeseed (Brassica napus)

1971 ◽  
Vol 49 (9) ◽  
pp. 1733-1735 ◽  
Author(s):  
A. J. Finlayson ◽  
C. M. Christ

Changes in seed nitrogen content, seed weight, precipitatable nitrogen (protein) content of maturing rapeseed show that there is a greater increase in precipitatable nitrogen during the early stages of seed development than at the later stages. Proteins found in the mature seed, however, are not detected until the last 3 weeks of seed growth. The deposition or completion of synthesis of the storage proteins apparently occurs over a 14-day period in rape.

1991 ◽  
Vol 1 (4) ◽  
pp. 203-208 ◽  
Author(s):  
A. E. Arthur ◽  
H. Adams ◽  
K. Strouts ◽  
D. A. Jones ◽  
T. L. Wang ◽  
...  

AbstractThe variation for protein content has been assessed in a series of pea (Pisum sativum L.) lines differing in mean seed size. The range of seed size within each genotype was manipulated by growing the plants in different environments and by altering the structure of the plant. The response of the lines in terms of seed weight to the environments and treatments was inconsistent, but 90% of the total variation was accounted for by differences between genotypes. In contrast, for percentage protein, the genetic component was much weaker with nearly half the variation being accounted for by within (residual) variation. The correlations between seed weight and percentage protein were highly genotype specific. For the largerseeded genotype, percentage protein increased with increasing seed size (r= +0.9, P < 0.01), while for the small-seeded genotype there was mid-range negative value (r = −0.5, P <0.01). It is suggested that any assessment of percentage protein in pea genotypes must take account of seed size.


Planta ◽  
2004 ◽  
Vol 218 (3) ◽  
pp. 483-491 ◽  
Author(s):  
Jinzhuo Dong ◽  
Wilf A. Keller ◽  
Wei Yan ◽  
Fawzy Georges

1973 ◽  
Vol 24 (1) ◽  
pp. 47 ◽  
Author(s):  
RJ Clements

Seedling growth of half-sib families from two lines of P. tuberosa previously selected for high and low herbage nitrogen contents respectively was examined in a glasshouse during the autumn and winter. Seedlings from the high nitrogen line were smaller than those of the low nitrogen line but had similar whole-plant relative growth rates. Differences in the rate of nitrogen absorption by the roots (h), and in the rate of seedling weight increase per unit of absorbed nitrogen (EN), accounted for most of the variation in herbage nitrogen content between families. The heights of seedlings were closely correlated with the weights of seeds from which they originated and with EN, and when these two characters were held constant the partial correlation between nitrogen content and seedling weight was negligible (r = -0.05). Among 10 clones differing markedly in herbage nitrogen content in the field, seed weight was closely correlated with the photosynthetic area above the flag leaf node available to each seed, particularly that contributed by the spikelet (r = 0.82***). Two alternative interpretations of this result are discussed. Relationships between nitrogen content, spikelet number, and the areas of photosynthesizing organs above the flag leaf node suggest that seed weight could be maintained during selection for increased nitrogen content by concurrently selecting either for large seeds, or for large flag leaves and a reduced number of spikelets per head. Even so, some loss of actual or potentially attainable seedling vigour seems almost inevitable because of the dependence of nitrogen content on IN and EN and because EN is an important determinant of vigour.


1989 ◽  
Vol 258 (1) ◽  
pp. 285-293 ◽  
Author(s):  
D J Murphy ◽  
I Cummins ◽  
A S Kang

The synthesis of the major protein and lipid storage reserves during embryogenesis in oilseed rape (Brassica napus L., cv. Mikado) has been examined by biochemical, immunological and immunocytochemical techniques. The mature seeds contained about 45% (w/w) storage oil and 25% (w/w) protein. There were three major seed protein components, i.e. about 40-50% total protein was cruciferin, 20% was napin and 20% was a 18 kDa hydrophobic polypeptide associated with the proteinaceous membrane surrounding the storage oil bodies. Embryogenesis was divided into four overlapping stages with regard to the synthesis of these storage components: (1) for the first 3 weeks after flowering, little, if any, synthesis of storage components was observed; (2) storage-oil synthesis began at about week 3, and maximal rates were from weeks 4 to 7; (3) synthesis of the soluble storage proteins cruciferin and napin started at week 6 and rates were maximal between weeks 8 and 11; (4) the final stage was the synthesis of the 19 kDa oil-body polypeptide, which started at weeks 8-10 and was at a maximal rate between weeks 10 and 12. The synthesis of the 19 kDa oil-body protein therefore occurred independently of the synthesis of the soluble seed storage proteins. This former synthesis did not occur until shortly before the insertion of the 19 kDa polypeptide into the oil-body membrane. No evidence was found, either from sucrose-density-gradient-centrifugation experiments or from immunogold-labelling studies, for its prior accumulation in the endoplasmic reticulum. Conventional and immunogold-electron-microscopic studies showed that oil bodies were synthesized in the early to middle stages of seed development without a strongly electron-dense membrane. Such a membrane was only found at later stages of seed development, concomitantly with the synthesis of the 19 kDa protein. It is proposed that, in rapeseed embryos, oil bodies are initially formed with no proteinaceous membrane. Such a membrane is formed later in development after insertion by ribosomes of the hydrophobic 19 kDa polypeptide directly into the oil bodies.


1984 ◽  
Vol 35 (4) ◽  
pp. 501 ◽  
Author(s):  
RW Downes ◽  
JS Gladstones

Plants of Lupinus angustifolius cv. Unicrop, with branches excised to eliminate competition between branches and the primary inflorescence, were raised at 21/16�C and transferred as flowering began to eight temperature regimes from 36/31 to 15/10�C for seed development. Vegetative growth rather than seed growth was stimulated by coolest conditions, although ultimate individual seed weight was greatest at the lowest temperatures. Plant growth was poor at temperatures above 27/22�C. Temperatures about 21/16�C were most suitable for seed development. In another experiment, plants with branches excised were grown at 27/22 or 18/13�C until flowering, when they were either retained in the same conditions or moved to the other. Conditions before flowering determined growth of the inflorescence for the first 24 days after flowering began, but conditions after flowering affected ultimate yield. Plants raised to flowering at 27/22�C were able to recover if exposed to 18/13�C after flowering. This suggested a possible role for lupins as an autumn crop where water is available.


1978 ◽  
Vol 58 (2) ◽  
pp. 549-550 ◽  
Author(s):  
J. M. CLARKE ◽  
F. R. CLARKE ◽  
G. M. SIMPSON

Broadcast and drill seeding of Brassica napus L. were compared at four seeding rates. Drill-seeded material yielded more than broadcast-seeded material, particularly at the low seeding rates. Broadcast-seeded plants had more branches and pods than drill-seeded plants. Seeding method did not affect number of seeds per pod or 1,000-seed weight.


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