Heterosis and combining ability estimates in spring-planted oilseed rape (Brassica napus L.)

1985 ◽  
Vol 27 (4) ◽  
pp. 472-478 ◽  
Author(s):  
I. Grant ◽  
W. D. Beversdorf

A 6 × 6 diallel cross was conducted in spring-planted oilseed rape (Brassica napus L.) in 1983 at Elora and Dundalk, Ontario. The F1 hybrids exhibited positive heterosis for seed yield, of up to 72%, over the higher-yielding parent in the hybrid crosses. Heterosis for 1000 seed weight, percent oil, plant height, and lodging resistance was nonsignificant; negative heterosis for percent protein was observed with some hybrids. Generally, the hybrids were intermediate to the parents in flowering date and physiological maturity. Specific combining ability was more important than general combining ability for seed yield, percent oil, percent protein, plant height (Dundalk), and lodging resistance (Elora); specific combining ability was as important as general combining ability for 1000 seed weight, physiological maturity, plant height (Elora), and lodging resistance (Dundalk). The cultivars 'Topas' and 'Regent' were the best general combiners for seed yield. The best specific combinations for seed yield heterosis, 'Westar' × 'Hanna', 'Regent' × 'Liné', and 'Regent' × 'D-1', exhibited average high-parent heterosis values of 50, 38, and 30%, respectively. The results demonstrated that considerable potential exists for producing high-yielding single-cross hybrids of oilseed rape. Commercial exploitation of this heterosis will depend on the successful development of suitable pollination control mechanisms.Key words: Brassica napus, oilseed rape, F1 hybrid, heterosis, combining ability.

2014 ◽  
Vol 67 (1) ◽  
pp. 61-74
Author(s):  
Valiollah Rameeh

Abstract Half F2 diallel crosses of spring rapeseed (Brassica napus L.) varieties along with their parents were evaluated for plant height, first siliqua height, siliquae on main axis, siliquae per plant, 1000-seed weight and seed yield. The Analysis of variance based on Cockerham’s method revealed significant mean squares of general combining ability (GCA), specific combining ability (SCA) for all the traits indicating that both additive and non-additive genetic effects were involved in controlling these traits. Parent vs crosses mean square which is indicating average heterosis was significant for all the traits. In Hayman’s method the regression lines estimated for all the traits except plant height cut the Wr axis below the origin in the negative zone, suggesting the overdominance type of gene action for these traits except plant height. Based on the array points on the regression lines, 19H had maximum dominant genes for siliquae on main axis, siliquae per plant 1000-seed weight and seed yield, being closest to the origin, while 0ption500 possessed recessive genes for first siliqua height, siliquae per plant and 1000-seed weight, as evidenced by its distant position from the origin. Due to low narrow-sense heritability estimates for most of the traits, selection for improving these traits should be carried out in delayed segregating generations.


2021 ◽  
Vol 66 (1) ◽  
pp. 17-25
Author(s):  
Valiollah Rameeh ◽  
Maryam Niakan ◽  
Mohammad Mohammadi

The effects of four sulphur levels: S0, S1, S2 and S3, including 0, 12, 24 and 36 kg S ha-1, respectively, along with 115 kg N ha-1 were studied on yield-related traits of oilseed rape (Brassica napus L.). The significant variance of treatments was determined for plant height, yield component characters, seed yield and oil content. The sulphur application significantly increased most of the traits compared to the S0 level. The S3 (36 kg S ha-1) treatment led to the highest mean value of plant height (132 cm) which was classified with S2 (24 kg S ha-1) in the same statistical group. Sulphur had an increasing effect on pods per plant, and it ranged from 92 to 196 for S0 and S3 applications, respectively. S0 and S1 with 92 and 121 pods per plant were grouped in the same statistical group. In addition, S2, and S3 with 165 and 196 pods per plant showed no significant statistical difference. The sulphur application significantly increased seed yield compared to control (S0 level), and it ranged from 2744 to 3215 kg ha-1 in S0 and S3, respectively. The average oil contents of 45.69, 46.96, 47.46 and 49.53 % were detected for 0, 12, 24 and 36 kg S ha-1, respectively.


2014 ◽  
Vol 47 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Ejaz Ul-Hasan ◽  
H.S.B. Mustafa ◽  
Tahira Bibi ◽  
T. Mahmood

ABSTRACT The present research was carried out to determine the best selection criteria for yield improvement in rapeseed (Brassica napus L.). Nine genotypes of Brassica napus were sown at Oilseeds Research Institute, Faisalabad, during the years 2011- 2012, to evaluate the means and components of variability (genotypic and phenotypic), heritability (h2 B.S), correlation (genotypic and phenotypic) and path analysis for yield and various yield components. At phenotypic and genotypic level, seed yield/plant had significant positive correlation with plant height, seeds/plant and siliqua/plant. A positive and highly significant genetic relationship was found between plant height and seeds/plant, siliqua length and seeds/siliqua, days to maturity and 1000 seed weight, days to flowering and seeds/plant, days to maturity and seeds/plant. Path coefficient revealed that the seeds/siliqua, 1000 seed weight, days to flowering, days to maturity and seeds/plant had direct positive contribution towards seed yield per plant. For rapeseed breeding seed per plant was the variable with maximum potential of selection for seed yield improvement because this trait possessed high h2 B.S, highly significant positive correlation and maximum positive direct effects with yield


1985 ◽  
Vol 65 (4) ◽  
pp. 889-892 ◽  
Author(s):  
IAN GRANT ◽  
WALLACE D. BEVERSDORF

The agronomic performance of eight triazine-resistant single-cross oilseed rape (B. napus L.) hybrids was evaluated. The yield of most of the hybrids was significantly greater than Atr-Regent; some of the hybirds demonstrated mid-parent heterosis, but none of the eight exhibited high-parent heterosis. In most cases the hybrids were intermediate to the parents for flowering date, plant height, lodging resistance, physiological maturity, percent oil and percent protein.Key words: Brassica napus L., oilseed rape, F1 hybrid, triazine resistance


2015 ◽  
Vol 4 (2) ◽  
pp. 330-340
Author(s):  
Sadia Shaukat ◽  
Dr Raziuddin ◽  
Fahim Ullah Khan ◽  
Ibni Amin Khalil

To investigate genetic variability and heritability, eight Brassica napus genotypes were evaluated at New Developmental Research Farm, Faculty of Agriculture. Peshawar University, during 2010-11. Analysis of variance revealed significant differences (P≤0.01) among Brassica napus genotypes for all the studied characters. Mean values showed that maximum primary branches plant-1 (15) was observed for genotype PGRI-8, plant height (220.66 cm) for genotype CH-6 and PGRI-8, pods main raceme-1 (96.33) for genotype CH-1, pods plant-1 (994) for genotype PGRI- 8, pod length (8.3 cm) for genotype PGRI- 7, seeds pod-1 (27) for genotype CH-1, 1000-seed weight (3.97 g) for genotype CH-2, and seed yield plant-1 (91.1 g) for genotype PGRI-8. In t terms of heritability values, high broad sense heritability estimates were observed for primary branches plant-1 (0.83), plant height (0.78), pods main raceme-1 (0.65), seeds pod-1 (0.61), 1000-seed weight (0.61), while moderate heritability values were recorded for pod length (0.57), pods plant-1 (0.55), and seed yield plant-1 (0.50). In conclusion, the significant differences among Brassica napus genotypes showed that there is sufficient variability for effective selection. The trend of heritability (moderate to high) in the present study indicates that there is more genetic control and selection should lead to quick improvement. Furthermore genotype PGRI-8 surpassed all other genotypes in yield and yield component and could be used in future breeding programs. DOI: http://dx.doi.org/10.3126/ije.v4i2.12661 International Journal of Environment Vol.4(2) 2015: 330-340


Author(s):  
E.B. Bochraryova ◽  
◽  
Е.А. Strelnikov ◽  
L.А. Gorlova ◽  
V.V. Serdyuk ◽  
...  

Combining ability (CA) of lines is one of the main criteria of estimation of the parental components of hybrids. There are existed the different crossing schemes for estimation of a combining ability. A method of top-cross is successfully used in a breeding practice. This method was used for estimation of a range of new CMS-lines of winter rapeseed perspective in breeding of simple interline hybrids. In our research we used six sterile lines on a base of CMS Ogura and six lines-restorers of fertility (testers). We obtained 36 test-hybrids for estimation of a combining ability of the lines. Positive combination of effects of the general combining ability (GCA) and variances of the specific combining ability (SCA), stable manifested in two years, we observed in two maternal lines 39712 and 40059. Hybrids with these lines had the higher average seed yield in two years of the research. These lines can be recommended for development of practically important hybrids of winter rapeseed. It is considered the testers possessing high GCA are promising for estimation of lines CA. in our research, two lines ORK 9 and ORK 21 demonstrated the high average seed yield of test-hybrids in two years of the research and can be recommended for usage as testers.


2012 ◽  
Vol 125 (2) ◽  
pp. 285-296 ◽  
Author(s):  
Pu Yang ◽  
Chang Shu ◽  
Lin Chen ◽  
Jinsong Xu ◽  
Jiangsheng Wu ◽  
...  

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