COMPARISON OF THE EFFECT OF nap AND pol CYTOPLASMS ON THE PERFORMANCE OF INTERCULTIVAR SUMMER OILSEED RAPE HYBRIDS

1990 ◽  
Vol 70 (1) ◽  
pp. 117-126 ◽  
Author(s):  
P. B. E. McVETTY ◽  
S. A. EDIE ◽  
R. SCARTH
Keyword(s):  
Male Sterility ◽  
Seed Yield ◽  
Total Protein ◽  
Dry Matter ◽  
Relative Effect ◽  
Protein Yield ◽  
Brassica Napus L ◽  
Biological Cost ◽  
Total Oil ◽  
The Cost

The objective of this study was to compare the performance of male fertility restored intercultivar F1 hybrids in the nap and pol cytoplasms to determine the relative effect on performance of these two male sterility inducing cytoplasms. F1 hybrids (all were 2n = 39 because a common 2n = 40 restorer line was used to produce the F1 hybrids) in both cytoplasms exhibited superior relative performance compared to the conventional cultivar Regent for seed yield, total dry matter and total protein yield. F1 hybrids in the pol cytoplasm performed significantly poorer than F1 hybrids in the nap cytoplasm for seed yield, total dry matter, harvest index, percent oil, total oil yield, and total protein yield. These results suggest a biological cost associated with the presence of the pol cytoplasm. The cost of the pol cytoplasm, relative to the nap cytoplasm, was affected by parental cultivar, but was consistent over a variety of environments.Key words: Cytoplasm cost, Brassica napus L., cytoplasmic male sterility, heterosis, hybrid

Seedling age and quality upon transplanting affect seed yield of canola (Brassica napus L.)

2014 ◽  
Vol 94 (8) ◽  
pp. 1461-1469 ◽  
Author(s):  
Yun Ren ◽  
Jianfang Zhu ◽  
Nazim Hussain ◽  
Shanlin Ma ◽  
Genru Ye ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Seed Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Seedling Quality ◽  
Leaf Number ◽  
Green Leaf ◽  
Brassica Napus L ◽  
Seedling Age ◽  
Neck Diameter

Ren, Y., Zhu, J., Hussain, N., Ma, S., Ye, G., Zhang, D. and Hua, S. 2014. Seedling age and quality upon transplanting affect seed yield of canola (Brassica napus L.). Can. J. Plant Sci. 94: 1461–1469. Seedling quality is an essential indicator for seed yield in canola, which is affected by many factors, including seedling age. Two field experiments were conducted to compare canola seedling quality and seed yield on 30-, 35-, 40-, 45-, 50-, 55-, and 60-d-old seedlings in 2011 and 2012. The relationship between seedling quality traits and seed yield of different seedling ages was also analyzed. Results revealed that the highest seed yield obtained from 40-d-old seedlings was attributed to more branches and siliques per plant. The negative effect of young seedlings (30-d-old) on seed yield was greater than that of old seedlings (60-d-old). The reduction rates in seed yield on the 30- and 60-d-old seedlings were 25.7 and 18.2%, respectively, compared with the 40-d-old seedlings. Increased root neck diameter, green leaf number, shoot, and root dry matter was the case on 40-d-old seedling transplanted plants compared with other ages. However, the increase was larger in the old seedlings than in the young seedlings. On average, the shoot and root dry weights of the 30-d-old seedlings were 1.9 and 1.7% of those in the 60-d-old seedlings. However, correlation analysis revealed that the seedlings with the highest shoot and root dry matter did not necessarily obtain the highest seed yield. Factor analysis suggested that the effects of root neck diameter and green leaf number on seed yield were more pronounced than those of shoot and root dry matter. Therefore, high seed yield in canola could be defined in terms of optimum green leaf numbers and branches per plant.

Comparison of the responses of two Indian mustard (Brassica juncea L.) genotypes to post-flowering soil water deficit with the response of canola (B. napus L.) cv. Monty

2009 ◽  
Vol 60 (3) ◽  
pp. 251 ◽  
Author(s):  
C. P. Gunasekera ◽  
R. J. French ◽  
L. D. Martin ◽  
K. H. M. Siddique
Keyword(s):  
Water Stress ◽  
Water Use ◽  
Seed Yield ◽  
Harvest Index ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Mild Stress ◽  
Matter Production ◽  
Oil Concentration ◽  
Total Oil

The responses to water stress during the post-flowering period of two mustard breeding lines (887.1.6.1 and Muscon) and a commercial canola cv. Monty were tested in the field at Merredin in the low-rainfall Mediterranean-type environment of Western Australia. Three water-stress treatments were imposed using supplemental irrigation and a rain-exclusion shelter. Increasing water stress in the post-flowering period significantly reduced dry matter production and seed yields. Harvest index was slightly increased by mild stress, but reduced back to control levels by severe stress. Pods/plant, seeds/pod, and 1000-seed weight were all reduced by water stress. Dry matter production was higher in mustard than in canola, due to its greater water use and radiation interception. Water-use efficiency (WUE) for dry matter production and radiation-use efficiency (RUE) were higher in mustard than in canola. WUE for dry matter production and RUE were insensitive to the levels of water stress in mustard in this experiment, but declined significantly in canola. The greater water use in mustard and insensitivity of WUE for dry matter production and RUE to water stress were attributed to significantly higher levels of osmotic adjustment in mustard, although osmotic adjustment was also observed in canola. Despite this, canola seed yield was not significantly lower than the seed yield of the better mustard genotype, although stress caused a significantly greater percentage yield reduction in canola. This is because canola had a higher harvest index, which also meant it had higher WUE than mustard for grain production under mild stress. Mustard’s poorer harvest index was due to more of the dry matter being invested in stem and, in the case of cv. Muscon, to a short reproductive duration and a low proportion of pod weight allocated to seed. Canola had significantly higher seed oil concentration than mustard, which meant that it produced higher total oil yield despite sometimes producing lower seed yield. However, its oil concentration was reduced more by stress than mustard’s, so under the most severe stress conditions, both mustard genotypes produced higher total oil yield. Mustard has potential as an oil-producing crop in the low-rainfall Mediterranean-type environments of Western Australia, but improved genotypes, greater harvest index, and greater seed yield are required.

Comparison of the effect of mur and nap cytoplasms on the performance of intercultivar summer rape hybrids

2004 ◽  
Vol 84 (3) ◽  
pp. 731-738 ◽  
Author(s):  
Teresio C. Riungu ◽  
Peter B. E. McVetty
Keyword(s):  
Brassica Napus ◽  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Protein Concentration ◽  
Hybrid Seed Production ◽  
Brassica Napus L ◽  
Oil Concentration ◽  
Good Potential ◽  
Biological Cost ◽  
Hybrid Group

The performance of six isogenic pairs of male fertility restored, hand-crossed, summer rape (Brassica napus L.) hybrids, in the mur and nap cytoplasms, were investigated in four Manitoba environments. Hybrids in both cytoplasms exhibited high-parent heterosis for seed yield, total dry matter (TDM) and, to a lesser degree, harvest index (HI). Negative high parent heterosis for days to flowering, days to maturity, oil concentration and protein concentration was observed. Combined over hybrids within cytoplasms, the mur and nap cytoplasmic hybrid groups differed in oil concentration in all environments, and in protein concentration in one of four environments. Similarly, the mur hybrid group was lower-yielding and had lower TDM, HI and oil concentration, but higher protein concentration than the nap hybrid group. Even though there are some biological costs associated with the mur cytoplasm, especially for oil concentration, it appears that the mur cytoplasmic male sterility (CMS) system has good potential for use in summer rape hybrid cultivar breeding and commercial hybrid seed production, since hybrids in the mur cytoplasm display heterosis for many traits in absolute terms. Key words: Biological cost, Brassica napus L., cytoplasmic male sterility, heterosis, hybrid

Yield improvement of oilseed rape (Brassica napus L.) in a low rainfall environment. II. Agronomic performance of lines selected on the basis of pre-anthesis development

1992 ◽  
Vol 43 (3) ◽  
pp. 623
Author(s):  
N Thurling ◽  
R Kaveeta
Keyword(s):  
Brassica Napus ◽  
Flowering Time ◽  
Seed Yield ◽  
Dry Matter ◽  
Stem Elongation ◽  
Dry Weight ◽  
Early Flowering ◽  
Rapid Decline ◽  
Recurrent Parent ◽  
Brassica Napus L

Agronomic characteristics of two groups of early flowering Brassica napus lines and their respective parents were compared at East Beverley in the Western Australian wheatbelt. These lines had been derived through two generations of backcrossing and subsequent selfing from crosses of the B. napus cultivar Wesbrook (recurrent parent) with an early flowering B. napus line RU2 and an even earlier flowering B. campestris population Chinoli C42. Lines selected for this experiment had flowered earliest in a previous controlled environment experiment. Only RU2 and one WesbrookxRU2 line (IB72) had significantly higher yields than Wesbrook (149% and 166% respectively), and one Wesbrookxchinoli C42 line was the only line to have a significantly lower yield than Wesbrook. None of the lines had significantly higher yields than their respective non-recurrent parents. Although RU2 and IB72 flowered much earlier than Wesbrook, there was no significant relationship between flowering time and seed yield over all lines. Lines which were the earliest to commence stem elongation tended to have higher seed yields. However, of all the growth and development characters measured, the biological yield and the dry weight increment between commencement of flowering and maturity were most closely related to seed yield. RU2 and IB72 accumulated far more dry matter over the post-anthesis period than Wesbrook and all other lines except another WesbrookxRU2 line. The superior post-anthesis growth of RU2 and IB72 may simply be a manifestation of the longer period available for growth under more favourable environmental conditions or deeper roots extracting more water from a greater depth. However, since there was no relationship between flowering time and the post-anthesis dry matter increment, it seems more likely that IB72 has received genes for superior post-anthesis growth as well as those determining early flowering from RU2. Given the rapid decline in soil moisture availability during post-anthesis development in this environment, these genes may affect post-anthesis growth through determining a greater capacity for drought avoidance. The implications of these results are discussed with particular reference to the breeding of higher yielding B. napus cultivars for lower rainfall environments.

SEED PRODUCTION OF HYBRID SUMMER RAPE IN THE FIELD USING THE POL CYTOPLASMIC MALE STERILITY SYSTEM: A FIRST ATTEMPT

1990 ◽  
Vol 70 (3) ◽  
pp. 611-618 ◽  
Author(s):  
R. PINNISCH ◽  
P. B. E. McVETTY
Keyword(s):  
Brassica Napus ◽  
Male Sterility ◽  
Seed Production ◽  
Seed Yield ◽  
Hybrid Seed ◽  
Male Sterile ◽  
Male Sterile Line ◽  
Brassica Napus L ◽  
Total Seed ◽  
Seed Yields

Hybrid summer rape (Brassica napus L.) seed production blocks were established at two locations in Manitoba in 1986 and 1987 to examine the effect of distance from the pollen source on seed yield, (both total and hybrid) and percent hybridity of seed produced on rows of a male sterile line of the open pollinated population B. napus cultivar, Marnoo, possessing the pol cytoplasmic male sterility inducing cytoplasm. A 10:1 ratio of male sterile line (A-line) to pollen parent was employed. Leaf cutter bees (Megachile rotundata F.) were used as the pollen vector between the two parents. In 1986, no significant differences in total seed yield were found among A-line rows, while in 1987, significant differences in total seed yields of A-line rows were found. Differences in hybrid seed yields among A-line rows were significant for all locations and years. Leaf cutter bees were found to be effective pollinators of the A-line plants. Less than half and less than a third of the seed produced on the A-line rows in 1986 and 1987, respectively, was hybrid seed. The high percentage of non-hybrid seed present in the seed lot may have been due to incomplete male sterility of the Marnoo A-line population. Total seed yields, hybrid seed yields and percent hybridity all declined linearly as distance from the pollen source increased. Improvement in the degree of male sterility of the Marnoo A-line population and/or a reduction in the 10:1 ratio of parents, and subsequent maximum A-line row to R-line row distance, will be necessary if hybrid summer rape seed production using this pol CMS A-line is to be commercially viable.Key words: Brassica napus L., CMS, hybrid, hybridity

Comparison of the effect of nap and pol cytoplasms on the performance of three summer oilseed rape cultivar-derived isoline pairs

1994 ◽  
Vol 74 (4) ◽  
pp. 729-731 ◽  
Author(s):  
P. B. E. McVetty ◽  
R. Pinnisch
Keyword(s):  
Brassica Napus ◽  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Oil Content ◽  
Relative Effect ◽  
Male Sterile ◽  
Negative Effects ◽  
Brassica Napus L ◽  
Male Sterile Cytoplasm ◽  
The One

The pol cytoplasm is a male sterile cytoplasm with potential for use in hybrid summer rape (Brassica napus L.) seed production while the nap cytoplasm is the one most commonly encountered in summer rape cultivars. The objective of this study was to compare the performance of three cultivar-derived summer rape isoline pairs in the nap and pol cytoplasms to determine the relative effect on performance of these two cytoplasms. One nap line yielded significantly more than its corresponding pol line, three nap lines had significantly higher oil content than their corresponding pol lines, two nap lines had significantly higher protein content than their corresponding pol lines, and two nap lines produced significantly more seed energy than their corresponding pol lines. There are pleiotropic negative effects (biological costs) associated with the pol cytoplasm. These negative effects are affected by nuclear genotype and appear to be related to the depth of male sterility expressed in the derived pol A-line. Key words: Cytoplasm cost, Brassica napus L., cytoplasmic male sterility

Evaluation of the cost of restoration of male fertility in Brassica napus

Botany ◽  
2014 ◽  
Vol 92 (11) ◽  
pp. 847-853 ◽  
Author(s):  
Benjamin R. Montgomery ◽  
Maia F. Bailey ◽  
Gregory G. Brown ◽  
Lynda F. Delph
Keyword(s):  
Brassica Napus ◽  
Sex Determination ◽  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Male Fertility ◽  
Fertility Restoration ◽  
Brassica Napus L ◽  
Pollen Counts ◽  
Restorer Genes ◽  
The Cost

Gynodioecy frequently results from the interplay of mitochondrial cytoplasmic male sterility (CMS) and nuclear fertility-restoration genes. Models suggest that maintaining cytonuclear gynodioecy requires that restorer genes incur a cost to fitness because otherwise they would increase toward fixation. Direct tests of costs of restorer alleles require knowledge of the underlying genetics of sex determination. We use a well characterized CMS system in Brassica napus L. to measure aspects of fitness in four lineages that vary in whether they carry the pol CMS gene or male-fertile cytoplasm (cam), and whether they carry the Rfp restorer of pol or Rfn restorer of the nap CMS gene. As expected, plants with pol CMS and only the Rfn restorer experienced reduced flower size, stamen length, and pollen counts. Plants with pol and the Rfp restorer showed incomplete restoration with shorter stamens than both lines with cam cytoplasm and reduced pollen counts compared with plants with cam cytoplasm and the Rfp restorer. Among plants with cam cytoplasm, pollen counts were higher for those with the Rfp than Rfn restorer, indicating a greater cost of restoration associated with Rfn. These results demonstrate that costs of restoration differ for the Rfn and Rfp alleles in B. napus.

Relationship of physiological characters to yield parameters in oilseed rape (Brassica napus L.)

2001 ◽  
Vol 81 (1) ◽  
pp. 1-6 ◽  
Author(s):  
G. Chongo ◽  
P. B. E. McVetty
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Seed Yield ◽  
Harvest Index ◽  
Dry Matter ◽  
Early Flowering ◽  
High Yield ◽  
Brassica Napus L ◽  
Unit Leaf ◽  
Leaf Chlorophyll

The physiological basis of seed yield in oilseed rape (Brassica napus L.) still remains unclear, and conclusions on the contribution of such traits to seed yield are difficult to make. Nine cultivars, classified into three yield groups (high, medium and low) based on significant differences in seed yield from previous trials, were tested over two locations and years. Leaf chlorophyll content, net photosynthetic rate per unit leaf area (PA), per unit leaf dry matter (PDM) and per unit leaf chlorophyll (PC), transpiration rate (TR) and water use efficiency (WUE) were investigated on fully expanded leaf numbers 4 (vegetative), 6 (early flowering) and 8 (early podding stage) on the main stem and related to seed yield, total dry matter (TDM) and harvest index (HI) of each yield group. Differences among yield groups for seed yield, TDM and HI were significant. Chlorophyll content was lowest on leaf 4, but increased with leaf age. Correlations between net photosynthetic rate and seed yield were not found. However, cultivars in the high yield group maximized their net photosynthetic rates (PA, PDM, and PC) on leaf 6 during early flowering at the time when TR was lowest and WUE at its highest. In the medium and low groups, photosynthetic rates were highest on leaf 4, but decreased to lowest values on leaf 8, together with the high yield group. In general, the results indicate that the largest contribution to net photosynthesis by oilseed rape leaves occurred during the vegetative and early flowering stages compared with the early pod-filling stage. Key words: Total dry matter, harvest index, photosynthesis, chlorophyll

EFFECT OF PLANT DENSITY ON DEVELOPMENT AND YIELD OF RAPESEED AND ITS SIGNIFICANCE TO RECOVERY FROM HAIL INJURY

1987 ◽  
Vol 67 (1) ◽  
pp. 43-51 ◽  
Author(s):  
D. I. McGREGOR
Keyword(s):  
Brassica Napus ◽  
Seed Yield ◽  
Seed Weight ◽  
Dry Matter ◽  
Brassica Campestris ◽  
Plant Density ◽  
Plant Population ◽  
Plant Populations ◽  
Brassica Napus L ◽  
Stage Of Development

The ability of rapeseed crops (Brassica campestris L. ’Torch’ and B. napus L. ’Tower’) to recover from, and compensate for, loss of plants at the early vegetative stage of development was investigated by hand thinning plant populations established at commercial seeding rates with commercial seeding equipment. Plant density was reduced from 100-200 plants m−2 to 40 plants m−2 with less than a 20% loss in seed yield. Seeds per pod and seed weight in some instances increased with reduced plant density. However, compensation was attributed predominantly to an increased number of pods on the remaining plants, which increased from 20-90 to as many as 600. Branching increased from as few as 3 to, in some instances, almost 40. With reduced plant population there was a tendency for increased and prolonged accumulation of dry matter by the plants following flowering.Key words: Brassica campestris L., Brassica napus L., rapeseed, development, seed yield, hail.

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