scholarly journals Activation of rape (Brassica napus L.) embryo during seed germination. III. Ultrastructure of dry embryo axis

2014 ◽  
Vol 53 (2) ◽  
pp. 171-186 ◽  
Author(s):  
Mieczysław Kuraś
Keyword(s):  
Brassica Napus ◽  
Cell Ultrastructure ◽  
Embryo Axis ◽  
Storage Material ◽  
Cell Organelles ◽  
Normal Appearance ◽  
Winter Rape ◽  
Brassica Napus L ◽  
Dense Cytoplasm ◽  
Storage Organs

Mature dry winter rape (<em>Brassica napus</em> L.), var. <em>oleifera</em>, cv. Górczański embryos were studied in the light and the electron microscope. Considerable modifications and regression of the cell ultrastructure were noted in the resting embryo as compared with the metabolically active cells. The degree of regression of the ultrastructure differed in the particular organs and tissues of the embryo. Of most regressed character are the cells of the storage organs - the hypocotyl and cotyledones. They are almost completely filled with protein and lipid bodies. The small spaces between them are filled with dense cytoplasm with a lobular nucleus and not numerous, difficult to identify, plastids and mitochondria. The cells of the shoot primordium and radicle, particularly of the protoderm at the boundary of the hypocotyl and root and columella of root cap have a less regressed ultrastructure. They contain less storage material, a less dense cytoplasm and nearly all cell organelles with a normal appearance. The mitochondria are quite numerous with rather large cristae. Plastids are large with characteristic infolds filled with cytoplasm and some lamellae and a few agglomerations of plastoglobules. The nucleus is lobular with distinctly double and porous nuclear envelope and uniformly dense nucleolus. These cells do not contain dictyosomes and the ER is reduced to short, mostly rough cisternae and vesicles. Cells within the columella itself are also differentiated. The least regression of ultrastructure is seen in the cells of external layers containing the most numerous and most active looking mitochondria and more ER structures. The promeristem cells are similar to those of the deeper columella layers but their mitochondria are more regressed. The cells of the lateral parts of the cap and radicle cells, distant from the promeristem are more similar to the hypocotyl cells.

scholarly journals Activation of rape (Brassica napus L.) embryo during seed germination. V. The first zones of ultrastructural changes and their expansion

2014 ◽  
Vol 56 (1) ◽  
pp. 77-91 ◽  
Author(s):  
Mieczysław Karaś
Keyword(s):  
Brassica Napus ◽  
Seed Germination ◽  
Seed Coat ◽  
Basal Part ◽  
Ultrastructural Changes ◽  
Embryo Axis ◽  
Brassica Napus L ◽  
Root Cells ◽  
Basal Zone

In the germinating rape embryo the columella and basal part of hypocotyl undergo earliest activation. Its first ultrastructural symptom is the appearance of numerous ER vesicles after 3-6 h of seed swelling. Their number is the highest in the external layers of the columella and decreases in basipetal direction. Dermatogen cells in the basal zone of the hypocotyl contain the greatest amount of ER structures, whereas decreasing amounts are found in both directions along the embryo axis and centripetally. Further changes in the ER spread in a similar order. The vesicles merge and form a tubular and plate-like ER. Then, they disappear and are replaced by tubular and vesicular forms. The changes in the ER are gradually followed by ultrastructural symptoms of activation of mitochondria, plastids and dictyosomes. The highest number of ER structures and other organelles accumulate in root cells shortly before piercing of the seed coat. After germination their amount decreases and remains almost stable.

scholarly journals Varietal Diversity of Seed Glucosinolates Content and its Composition in Japanese Winter Rape (Brassica napus L.).

1995 ◽  
Vol 45 (3) ◽  
pp. 357-364
Author(s):  
Masahiko Ishida ◽  
Yoshinao Okuyama ◽  
Yoshihito Takahata ◽  
Norihiko Kaizuma
Keyword(s):  
Brassica Napus ◽  
Varietal Diversity ◽  
Winter Rape ◽  
Brassica Napus L ◽  
Seed Glucosinolates

scholarly journals DOUBLE CROPPING WINTER RAPESEED AND GRAIN SORGHUM

1986 ◽  
Vol 66 (3) ◽  
pp. 425-430 ◽  
Author(s):  
R. R. DUNCAN ◽  
C. S. HOVELAND
Keyword(s):  
Glycine Max ◽  
Brassica Napus ◽  
Cropping System ◽  
Grain Sorghum ◽  
Winter Rape ◽  
Brassica Napus L ◽  
Double Cropping ◽  
Glycine Max L ◽  
Winter Rapeseed ◽  
Sorghum Bicolor L

Since rainfall generally exceeds 500 mm during the winter months and soil erosion is a problem in the southern U.S.A., a cover crop is essential to reduce soil losses. Continuous cultivation of a crop on the same land also provides the opportunity for pest problems to develop. A winter rapeseed (Brassica napus L.)-grain sorghum (Sorghum bicolor (L). Moench.) double-cropping system was investigated in the field from 1981 to 1984. Conventional tillage (CT) and no-till (NT) systems were used for both crops. Gullivar rape was planted in October and harvested in June. Winter rapeseed yields averaged 2.87 t ha−1 on CT plots in 1982. Averaged over 1983 and 1984, rape yields were 1.66 and 0.73 t ha−1 on CT and NT plots, respectively. However, the seeding method biased the rapeseed performance. Problems were encountered with winter weed control and pod shattering in the winter rape plots. Two sorghum hybrids, R. C. Young Oro Txtra and Funks G-550, were planted in June and harvested in October. Grain yields were not significantly different between hybrids (Oro 5.69 t ha−1, Funk 5.67 t ha−1) or between tillage systems (CT 5.59 t ha−1, NT 5.78 t ha−1). Grain yield differences were noted for year × hybrid × tillage interactions. Rape was a weed problem in the sorghum plots. The winter rape-sorghum double-cropping system offers an alternative to current winter small grains-sorghum/soybean (Glycine max (L.) Merr.) or winter annual legume-sorghum/soybean (Glycine max (L.) Merr.) systems; however, markets for the winter rapeseed and production economic analyses are needed prior to adoption of the system. Additional winter rapeseed research is needed to evaluate yields properly under NT conditions.Key words: Sorghum bicolor (L.) Moench, Brassica napus L., conservation tillage, multiple cropping, sorghum, rapeseed

EFFECT OF FROST ON HULL STRUCTURE OF CANOLA SEEDS

1984 ◽  
Vol 64 (4) ◽  
pp. 841-848 ◽  
Author(s):  
J. T. MILLS ◽  
L. VAN CAESEELE ◽  
J. K. DAUN
Keyword(s):  
Brassica Napus ◽  
Seed Development ◽  
Frost Damage ◽  
Canola Seed ◽  
Normal Appearance ◽  
Arrested Development ◽  
Brassica Napus L ◽  
Secondary Thickening ◽  
Hull Structure ◽  
Damage Type

Two lots of severely frost-damaged canola seeds (Brassica napus L. ’Regent’) were categorized according to damage type. Seeds from these lots ranged in gross morphology from normal appearance to severely shrivelled with reduced diameter and white patches over the surface. The white color of these patches was caused by accumulation of starch-like granules in the epidermal layers. Frost-damaged hulls showed a variety of symptoms resulting from arrested development. In addition to an accumulation of starch-like granules in the epidermis, frost-damaged hulls displayed abnormal secondary thickening in the palisade.Key words: Frost-damage, canola, seed development, hull structure

Cytogenetic analysis of plants regenerated from tissue explants and mesophyll protoplasts of winter rape, Brassica napus L.

1984 ◽  
Vol 26 (6) ◽  
pp. 752-761 ◽  
Author(s):  
C. A. Newell ◽  
M. L. Rhoads ◽  
D. L. Bidney
Keyword(s):  
Brassica Napus ◽  
Chromosome Number ◽  
Germ Line ◽  
Male Sterile ◽  
Male Sterile Line ◽  
Winter Rape ◽  
Brassica Napus L ◽  
Mesophyll Protoplasts ◽  
Regenerated Plants ◽  
Chromosome Associations

Plants were regenerated from seedling tissue explants of four lines of winter rape (Brassica napus L.) including a cytoplasmic male sterile line carrying Raphanus sativus L. cytoplasm, and from leaf mesophyll protoplasts of the cytoplasmic male sterile line. Chromosome number variability was investigated in 102 regenerated plants. Mitotic root-tip cells were scored initially; those plants exhibiting mixoploidy or an altered chromosome number were reexamined at meiosis to confirm the presence of alterations in germ line cells. Plants regenerated from seedling explants included 2n = 38 diploids (87.0%) similar to the parental line, monosomics (7.8%), trisomics (2.6%), and 2n = 76 tetraploids (1.3%). The germ line number was not resolved in one mixoploid (1.3%). Protoplast-derived regenerated plants were diploid (44%), hypodiploid (20%), and tetraploid or hypotetraploid (36%). Meiotic analysis of regenerated plants showed a range of multiple chromosome associations with no plants consistently exhibiting bivalent formation only. Chromosomal alterations other than number may have been induced by culture, but could not be substantiated since multiple chromosome associations were also frequent in control plants grown from seed.Key words: plant regeneration, protoplast regeneration, Brassica napus, cytogenetics.

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