Diallel analysis of vernalisation responses in spring rape (Brassica napus L.): a basis for adaptation to a Mediterranean environment

1999 ◽  
Vol 50 (8) ◽  
pp. 1417 ◽  
Author(s):  
S. R. Dahanayake ◽  
N. W. Galwey
Keyword(s):  
Genetic Variation ◽  
Brassica Napus ◽  
Stem Elongation ◽  
Selection Criterion ◽  
Genetic Effects ◽  
Mediterranean Environment ◽  
Stem Height ◽  
Brassica Napus L ◽  
Time To Initiation ◽  
Spring Rape

The capacity for vernalisation varies among genotypes of spring rape, Brassica napus L., and any vernalisation response reduces their suitability for cultivation in the Mediterranean environment of south-western Western Australia. The genetic basis of this variation was studied in the F1 generation of a diallel cross among 5 inbred genotypes derived from a cross between 2 cultivars differing in sensitivity to vernalisation. In non-vernalised plants the number of leaf nodes at flowering, time to flowering, stem height at flowering, and time to initiation of stem elongation showed substantial genetic variation, both additive and dominance effects being significant. The time to initiation of stem elongation was not vernalisation-sensitive, but for the other 3 characters the response to vernalisation showed significant genetic variation, largely additive. The genetic effects controlling the number of leaf nodes at flowering were clearly different from those controlling stem height at flowering, and hence could be manipulated independently by selection. Moreover, the genetic effects controlling these characters in the absence of vernalisation were different from those controlling the response to vernalisation. Discontinuities in the distributions of the parent means and other statistics for the number of leaf nodes at flowering suggested that major Mendelian genes may largely control this character and its response to vernalisation. Comparison of the number of leaf nodes at flowering in the presence and absence of a vernalising stimulus is therefore suggested as a selection criterion for the elimination of vernalisation response. However, in the absence of a vernalising stimulus, the time to flowering will be the character easiest to influence by selection.

Evaluation of yield and agronomic traits and their genetic variation in 488 global collections of Brassica napus L.

2014 ◽  
Vol 61 (5) ◽  
pp. 979-999 ◽  
Author(s):  
Biyun Chen ◽  
Kun Xu ◽  
Jun Li ◽  
Feng Li ◽  
Jiangwei Qiao ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Brassica Napus ◽  
Agronomic Traits ◽  
Brassica Napus L

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.

Introgression of long pod genotype from spring rape (Brassica napus L.) into summer turnip rape (Brassica rapa L.)

2001 ◽  
Vol 81 (1) ◽  
pp. 59-60 ◽  
Author(s):  
L. J. Lewis ◽  
D. L. Woods ◽  
B. F. Cheng
Keyword(s):  
Brassica Napus ◽  
Key Words ◽  
Seed Size ◽  
Brassica Rapa ◽  
Interspecific Hybridisation ◽  
Brassica Napus L ◽  
Turnip Rape ◽  
Pod Length ◽  
Spring Rape

Long pod character from a summer Brassica napus L. line was introgressed into turnip rape B. rapa L. cultivar AC Sunshine resulting in progeny lines with significantly longer pods and larger seed size than those of AC Sunshine, but producing no yield advantage. Key words: Brassica rapa, Brassica napus, pod length, summer turnip rape, spring rape, interspecific hybridisation

Genetic analysis of embryo, cytoplasmic, and maternal effects and their environment interactions for protein content in Brassica napus L.

2005 ◽  
Vol 56 (1) ◽  
pp. 69 ◽  
Author(s):  
J. G. Wu ◽  
C. H. Shi ◽  
H. Z. Zhang
Keyword(s):  
Brassica Napus ◽  
Protein Content ◽  
Genetic Model ◽  
Interaction Effects ◽  
Genetic Effects ◽  
Ge Interaction ◽  
Brassica Napus L ◽  
Diallel Mating Design ◽  
Selection For ◽  
Main Effects

A genetic model for quantitative traits of seeds in diploid plants was applied to estimate the genetic main effects and genotype × environment (GE) interaction effects for protein content (PC) of rapeseed (Brassica napus L.) by using 2 years of experimental data with a diallel mating design of 8 parents. Results showed that PC of rapeseed was simultaneously controlled by genetic effects of embryo, cytoplasm, and maternal plant, of which the maternal genetic effects were most important, followed by embryo and cytoplasmic genetic effects. Therefore, improvement of PC of rapeseed would be more efficient when selection is based on maternal plants than that on single seeds. Since the GE interaction effects accounted for about 60.10% of total genetic effect, they were more important than the genetic main effects, and selection for PC might be influenced by environmental conditions. The total narrow-sense heritability for PC was 64.17%, of which the interaction heritability was larger than the general heritability. Selection for improving PC can therefore be conducted in early generations. Maternal heritability (41.59%) was most important for PC, followed by cytoplasmic heritability (17.62%) and then by embryo heritability (5.25%). Based on prediction of genetic effects, parent Youcai 601 was better than others for increasing PC in rapeseed breeding.

scholarly journals Effects of Water Deficit Stress on Several Quantitative and Qualitative Characteristics of Canola (Brassica napus L.) Cultivars

2011 ◽  
Vol 3 (3) ◽  
pp. 120-125 ◽  
Author(s):  
Mohammad HOSSEINI ◽  
Payman HASSIBI
Keyword(s):  
Brassica Napus ◽  
Water Deficit ◽  
Harvest Index ◽  
Stem Elongation ◽  
Early Flowering ◽  
Water Deficit Stress ◽  
Flowering Stage ◽  
Brassica Napus L ◽  
Early Emergence ◽  
Biological Yield

Water deficit stress considered as one of the most important limiting factors for oil seed canola (Brassica napus L.) growth and productivity in Iran. To evaluate the effects of water deficit stress on some qualitative and quantitative characteristics of canola cultivars, this experiment in a greenhouse trial carried out as factorial based on completely randomized design with three replications in Shahid Chamran University of Ahwaz (Iran). Canola cultivars, including ‘Hyola 308’, ‘Hyola 401’ and ‘RGS 003’ as first factor, and the second one was three levels of water deficit stress, including stress at early stem elongation stage to early flowering (D1), early flowering stage to early emergence of sacs (D2), beginning of stem elongation stage to early emergence of sacs (D3) and normal irrigation (C, as check). Results showed that the interaction between water deficit stress and cultivars affected biological yield, seed oil yields and harvest index (p≤0.01), dry matter and economic yield (p≤0.05). Water deficit stress reduced grain oil yields. ‘Hyola 308’ under stress at beginning stem elongation stage to early flowering had the lowest oil yields (1.1 g plants-1) and ‘Hyola 401’ under non-stress conditions showed highest oil yields (4.3 g plants-1). The decrease of oil yields at the flowering stage to stem elongation stage was more than the other stages. In addition, water deficit stress reduced harvest index in the three stress levels due to reduced economic yield and reduced biological yield. Stress susceptibility index for ‘Hyola 401’ at the beginning of stem elongation stage to early emergence of sacs was 0.914 and the ‘Hyola 308’ showed 1.12 at the beginning of stem elongation stage to early emergence of sacs respectively, which it can implies that ‘Hyola 308’ is more sensitive than ‘Hyola 401’ to water deficit stress.

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