Effects of genotype and environment on seed chlorophyll degradation during ripening in four cultivars of oilseed rape (Brassica napus)

1992 ◽  
Vol 72 (3) ◽  
pp. 643-649 ◽  
Author(s):  
K. Ward ◽  
R. Scarth ◽  
P. B. E. McVetty ◽  
J. Daun
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Chlorophyll Degradation ◽  
Moisture Loss ◽  
Major Influence ◽  
Canola Seed ◽  
Seeding Rate ◽  
Chlorophyll Breakdown ◽  
Seeding Date ◽  
Influence Of Temperature On

The rate of chlorophyll degradation in ripening canola seed was investigated using two sowing dates in each of 2 yr at one location and four cultivars of oilseed rape (Brassica napus), Westar, Regent, Global and Tribute. In general, the cultivars had the same rate of chlorophyll breakdown when grown in the same environment. All cultivars had a slower rate of chlorophyll breakdown in the late versus the early seeding date. The chlorophyll degradation rate using log ppm chlorophyll versus days showed significant differences between the two seeding dates and 2 yr in the study. The use of growing degree days (GDD) to determine rate of chlorophyll degradation removed many of these significant differences, confirming a major influence of temperature on the rate of chlorophyll breakdown. A second study correlating swathing date and chlorophyll levels in harvested canola seed indicated that rapid moisture loss from the seed fixed the chlorophyll at a higher level than that obtained with a slow moisture loss. Seeds harvested from the side branches contained more chlorophyll than seeds from the main stems. Late seeding resulted in higher seed chlorophyll levels at harvest. Low seed chlorophyll levels could be achieved if canola was sown early, using a high seeding rate to reduce branching, and swathed at physiological maturity under conditions which allow for slow moisture loss from the seed in the field.Key words: Oilseed rape, seed chlorophyll, Brassica napus

Chlorophyll degradation in summer oilseed rape and summer turnip rape during seed ripening

1995 ◽  
Vol 75 (2) ◽  
pp. 413-420 ◽  
Author(s):  
K. Ward ◽  
R. Scarth ◽  
J. K. Vessey ◽  
J. K. Daun
Keyword(s):  
Oilseed Rape ◽  
Ethylene Production ◽  
Genotypic Variation ◽  
Seed Mass ◽  
Chlorophyll Degradation ◽  
Moisture Loss ◽  
Turnip Rape ◽  
Chlorophyll Breakdown ◽  
Seed Moisture ◽  
Endogenous Ethylene

Chlorophyll breakdown in ripening seed of three summer rape cultivars (Brossica napus L.) and one summer turnip rape cultivar (Brassica rapa L.) was investigated to clarify the influence of genotype, environment, seed moisture and endogenous ethylene production. Final seed chlorophyll levels were determined for summer oilseed rape and turnip rape cultivars grown at several locations during 4 yr. Both genotype and environment affected seed chlorophyll levels at harvest, but genotype by environment interactions were minimal for the cultivars included in this study. Differences in maturity did not adequately explain the genotypic variation among the rape cultivars tested. Rates of seed chlorophyll breakdown, moisture loss and ethylene evolution were measured in ripening seeds of three rape cultivars. Stellar, Delta and Westar had significantly different rates of seed chlorophyll breakdown. Lower temperatures resulted in slower chlorophyll degradation. Chlorophyll and moisture (expressed as percentage seed mass) were positively correlated in ripening seed, but moisture loss occurred at the same rate during seed ripening in all cultivars and environments. Chlorophyll and endogenous ethylene production were positively correlated, but the peak of ethylene production occurred after moisture loss and chlorophyll breakdown had begun, implying that an increase in endogenous ethylene was not the trigger for the initiation of these events. Key words: Chlorophyll degradation, green seed, ripening, moisture loss, ethylene, oilseed rape, turnip rape

Effect of seeding date on canola seed quality and seed vigour

2004 ◽  
Vol 84 (2) ◽  
pp. 463-471 ◽  
Author(s):  
L. V. Gusta ◽  
E. N. Johnson ◽  
N. T. Nesbitt ◽  
K. J. Kirkland
Keyword(s):  
Brassica Napus ◽  
Seed Quality ◽  
Seedling Emergence ◽  
Germination Percentage ◽  
Canola Seed ◽  
Higher Plant ◽  
Seedling Vigour ◽  
Seed Vigour ◽  
Seeding Date ◽  
The Impact

Seedling vigour is a key critical component to produce well-established canola (Brassica napus) seedlings under less than ideal conditions in western Canada. Our objective was to determine if seed lots from late October (fall) or early spring (April) seeding dates improve seed vigour relative to mid-May (May) seeding dates. We compared seed size, seed maturity, germination percentage, and seedling emergence under controlled-environment conditions from six seed lots obtained from fall-sown (1997, 1998), April-sown (1998, 1999) and May-sown canola (1998, 1999) cv. Quest. On average, 80% of fall-derived seed for both years was larger than 1.7 mm compared to only 32% for May-derived canola seed. April-derived seed was intermediate. Fall and April derived seed were considered 40% mature compared to 16% for May-derived seed. In germination tests at 8°C, May derived seed germinated and emerged slower with a lower total germination percentage compared to falland April-derived seed lots. Priming reduced differences in emergence between the seed lots. Field studies at Scott, SK, sown in the fall of 1999 and 2000, and in early May of 2000 demonstrated that seed derived from fall- and April-sown canola produced higher plant densities, higher biomass at bolting, and higher seed yield than seed derived from May-sown canola. Yield was 10 to 45% less from seed derived from May-sown canola than seed derived from fall- and April-sown canola. This study established the impact of seeding date on seed quality and vigour, which in turn affected emergence, seedling vigour and yield. Also, seed vigour slowly declined within 1 yr, primarily with seed derived from the May-sown canola. Key words: Canola, Brassica napus, vigour (seed), seeding (fall), emergence, yield (quality)

Alternative seeding dates (fall and April) affect Brassica napus canola yield and quality

2000 ◽  
Vol 80 (4) ◽  
pp. 713-719 ◽  
Author(s):  
Ken J. Kirkland ◽  
Eric N. Johnson
Keyword(s):  
Brassica Napus ◽  
Seed Yield ◽  
Seed Weight ◽  
Oil Content ◽  
Plant Density ◽  
Yield Response ◽  
Canola Seed ◽  
Yield And Quality ◽  
Seeding Date ◽  
Herbicide Tolerant

Brassica napus L. canola production on the Canadian prairies often is limited by hot, dry growing conditions in early July and a short growing season. Brassica napus canola seeded in the fall just prior to freeze-up or in the early spring as soon as fields are passable may allow canola to avoid these adverse conditions. Our objective was to determine if late October (fall), or mid- to late April (April) seeding dates improve canola yield and quality relative to a mid-May (15 to 20 May) seeding date. Plant density and height, phenological development, seed yield, seed weight and seed oil content were assessed in plots sown to herbicide-tolerant B. napus canola at three seeding dates on five fallow sites and three stubble sites at Scott, SK, from 1994 to 1998. A thinner plant stand occurred for the fall compared with spring seeding dates; however, this difference rarely corresponded with less canola yield. Fifty percent flowering occurred 20 d earlier (June rather than July), reproductive growth (50% flowering to maturity) was 10 d longer, plants were 23 (fall) or 8 (April) cm shorter, and maturity occurred 13 d earlier when canola was seeded in the fall and April compared with mid-May seeding. Canola seed yield was 38% greater when seeded on the alternative dates rather than the more traditional mid-May seeding date. The yield advantage for alternative seeding dates was greater and more consistent on stubble than on fallow likely because of lack of soil crusting and temperature and wind protection from stubble. The response of seed weight to seeding date was similar to that for seed yield, indicating that a portion of the positive yield response to alternative seeding dates was associated with larger seed size. Oil content also was greater for the fall and April compared with mid-May seeding dates, but the improvement was smaller (6%) than that for seed yield. Fall- and April-seed-ed canola tolerated spring frosts and avoided adversely hot, dry weather during the flowering period, thus improving canola seed yield and quality. Alternative seeding dates provide canola producers in semi-arid regions with a sustainable option to diversify their cropping systems. Key words: Seeding date, dormant, stubble, fallow, herbicide tolerant, alternative cropping practice

THE INFLUENCE OF SEEDING DATE AND SEEDING RATE ON SEED YIELD AND YIELD COMPONENTS OF FIVE GENOTYPES OF Brassica napus

1981 ◽  
Vol 61 (2) ◽  
pp. 175-183 ◽  
Author(s):  
D. F. DEGENHARDT ◽  
Z. P. KONDRA
Keyword(s):  
Brassica Napus ◽  
Plant Height ◽  
Seed Yield ◽  
Seed Weight ◽  
Harvest Index ◽  
Plant Density ◽  
Unit Area ◽  
Total Yield ◽  
Seeding Rate ◽  
Seeding Date

The effects of seeding date and seeding rate on the agronomic characteristics of five genotypes of Brassica napus L. were studied for 2 yr at two locations in western Canada. Delayed seeding resulted in a significant increase in vegetative and total yield but a significant decrease in seed yield, harvest index, plant density, racemes per plant and racemes per unit area. Seeding date had no significant effect on seed yield per plant, 1000-seed weight and plant height. Increased seeding rate resulted in a significant increase in plant density, and racemes per unit area, but a significant decrease in harvest index, racemes per plant, seed yield per plant and plant height. Seeding rate had no significant effect on seed, vegetative or total yield and 1000-seed weight. There were significant differences due to genotypes for all variables except for total yield and racemes per unit area.

scholarly journals THE INFLUENCE OF SEEDING DATE AND SEEDING RATE ON SEED YIELD AND GROWTH CHARACTERS OF FIVE GENOTYPES OF Brassica napus

1981 ◽  
Vol 61 (2) ◽  
pp. 184-189 ◽  
Author(s):  
D. F. DEGENHARDT ◽  
Z. P. KONDRA
Keyword(s):  
Brassica Napus ◽  
Seed Yield ◽  
Western Canada ◽  
Flowering Period ◽  
Seeding Rate ◽  
Brassica Napus L ◽  
Seed Formation ◽  
Agronomic Characteristics ◽  
Seeding Date ◽  
Growth Characters

The effects of seeding date and seeding rate on the agronomic characteristics of five genotypes of Brassica napus L. were studied for 2 yr at two locations in western Canada. Seeding date had a highly significant effect on seed yield, days to first flower, last flower, and maturity of first pod, and no significant effect on flowering period and seed formation period. Generally, the latest seeding date, at all seeding rates and for all genotypes, resulted in the lowest seed yield and the fewest days to first flower, last flower, and maturity of first pod. Seeding rate has a significant effect on days to last flower, maturity of first pod, and seed formation period, but no significant effect on seed sield, first flower and flowering period. Generally, the highest seeding rate at all seeding dates and for all genotypes resulted in the fewest days to last flower and maturity of first pod, and shortest seed formation period.

scholarly journals Genome Mining and Evaluation of the Biocontrol Potential of Pseudomonas fluorescens BRZ63, a New Endophyte of Oilseed Rape (Brassica napus L.) against Fungal Pathogens

2020 ◽  
Vol 21 (22) ◽  
pp. 8740
Author(s):  
Daria Chlebek ◽  
Artur Pinski ◽  
Joanna Żur ◽  
Justyna Michalska ◽  
Katarzyna Hupert-Kocurek
Keyword(s):  
Brassica Napus ◽  
Plant Growth ◽  
Pseudomonas Fluorescens ◽  
Oilseed Rape ◽  
Plant Growth Promotion ◽  
Fungal Pathogens ◽  
Growth Promotion ◽  
Genome Mining ◽  
Plant Colonization ◽  
Brassica Napus L

Endophytic bacteria hold tremendous potential for use as biocontrol agents. Our study aimed to investigate the biocontrol activity of Pseudomonas fluorescens BRZ63, a new endophyte of oilseed rape (Brassica napus L.) against Rhizoctonia solani W70, Colletotrichum dematium K, Sclerotinia sclerotiorum K2291, and Fusarium avenaceum. In addition, features crucial for biocontrol, plant growth promotion, and colonization were assessed and linked with the genome sequences. The in vitro tests showed that BRZ63 significantly inhibited the mycelium growth of all tested pathogens and stimulated germination and growth of oilseed rape seedlings treated with fungal pathogens. The BRZ63 strain can benefit plants by producing biosurfactants, siderophores, indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and ammonia as well as phosphate solubilization. The abilities of exopolysaccharide production, autoaggregation, and biofilm formation additionally underline its potential to plant colonization and hence biocontrol. The effective colonization properties of the BRZ63 strain were confirmed by microscopy observations of EGFP-expressing cells colonizing the root surface and epidermal cells of Arabidopsis thaliana Col-0. Genome mining identified many genes related to the biocontrol process, such as transporters, siderophores, and other secondary metabolites. All analyses revealed that the BRZ63 strain is an excellent endophytic candidate for biocontrol of various plant pathogens and plant growth promotion.

Amino acid contents and transport in oilseed rape (Brassica napus L.) under different nitrogen conditions

Planta ◽  
2004 ◽  
Vol 221 (3) ◽  
pp. 328-338 ◽  
Author(s):  
Jens Tilsner ◽  
Nina Kassner ◽  
Christine Struck ◽  
Gertrud Lohaus
Keyword(s):  
Amino Acid ◽  
Brassica Napus ◽  
Oilseed Rape ◽  
Brassica Napus L ◽  
Amino Acid Contents ◽  
Nitrogen Conditions

Management of wild oat (Avena fatua L.) in tame oat (Avena sativa L.) with early seeding dates and high seeding rates

2009 ◽  
Vol 89 (4) ◽  
pp. 763-773 ◽  
Author(s):  
W E May ◽  
S J Shirtliffe ◽  
D W McAndrew ◽  
C B Holzapfel ◽  
G P Lafond
Keyword(s):  
Grain Yield ◽  
Avena Sativa ◽  
Test Weight ◽  
Wild Oat ◽  
Seeding Rate ◽  
Yield And Quality ◽  
Seeding Date ◽  
Grain Yield And Quality ◽  
Oat Biomass ◽  
Density Treatment

Traditionally, farmers have delayed seeding to manage wild oat (Avena fatua L.) in tame oat (Avena sativa L.) crops, but this practice can adversely affect grain yield and quality. The objectives of this study were: (1) to evaluate the effectiveness of using high seeding rates with early-seeded oat to maintain grain yield and quality, and (2) to determine an optimum seeding rate to manage wild oat and maximize grain yield and quality. The factors of interest were wild oat density (low and high density), seeding date (early May, mid May, early June and mid June), and tame oat seeding rate (150, 250, 350 and 450 viable seeds m-2). The study was conducted at Indian Head and Saskatoon, SK, in 2002, 2003 and 2004, at Winnipeg, MB, in 2002, and at Morden, MB, in 2003 and 2004. Wild oat biomass, wild oat panicle density and wild oat seed in the harvested sample decreased as seeding rate increased, while tame oat biomass and grain yield increased. Wild oat density ranged between 0 and 100 plants m-2 with averages of 10 plants m-2 in the low density treatment and 27 plants m-2 in the high density treatment. At low seeding rates, grain yield decreased with increasing wild oat density. The difference in grain yield between the two wild oat densities decreased as the seeding rate increased. There was a curvilinear decrease in grain yield as seeding was delayed. A seeding date × seeding rate interaction was noted for test weight, plump seed, thin seed and groat yield. Seed quality improved as seeding rate increased for only the mid-June seeding date. Even though the mid-June test weight increased as the seeding rate increased it was always lower than the early May test weight at any seeding rate. The results from this study established that in the presence of wild oats, early seeding of tame oat is possible providing high seeding rates, 350 plants m-2 are used.Key words: Wild oat competition, wild oat density, wild oat biomass, grain yield, grain quality

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