Continuing innovation in Australian canola breeding

2016 ◽  
Vol 67 (4) ◽  
pp. 266 ◽  
Author(s):  
Phillip A. Salisbury ◽  
Wallace A. Cowling ◽  
Trent D. Potter

Innovation has been integral in the development of the current Australian canola (Brassica napus L.) industry. From the initial introduction of poorly adapted Canadian germplasm, Australian breeders have developed high yielding, high quality, disease-resistant canola cultivars. The Australian canola industry has transitioned from being reliant on imports to becoming one of the world’s major exporters of canola. This review details the progressive innovations in the Australian canola breeding programs from the initial introduction of rapeseed to more recent developments including herbicide resistance, hybrid cultivars, speciality oil types and genetically modified canola.

1994 ◽  
Vol 74 (2) ◽  
pp. 275-277 ◽  
Author(s):  
L. A. Murphy ◽  
R. Scarth

Early maturity is a major objective of oilseed rape (Brassica napus L.) breeding programs in western Canada. Maturity of crops is influenced by time of initiation and flowering. The presence of a vernalization requirement affects plant development by delaying floral initiation until the cold requirement of the plant has been satisfied. Five spring oilseed rape cultivars were screened for their response to vernalization. Vernalization treatments consisted of exposure of germinated seeds to 0–42 d at 4 °C. Plants were assessed under a 20-h photoperiod. In general, there was a cumulative response to vernalization, with a decrease in days to each developmental stage as exposure to 4 °C was increased. Vernalization treatment of 6 d at 4 °C was sufficient to decrease both the days to first flower and the final leaf number. The characterization of vernalization response is of interest because variation in flowering time in response to year-to-year variations in the environment could result. Key words:Brassica napus, canola, oilseed rape, vernalization


2020 ◽  
Vol 21 (4) ◽  
pp. 1345
Author(s):  
Qianxin Huang ◽  
Jinyang Lv ◽  
Yanyan Sun ◽  
Hongmei Wang ◽  
Yuan Guo ◽  
...  

The use of herbicides is an effective and economic way to control weeds, but their availability for rapeseed is limited due to the shortage of herbicide-resistant cultivars in China. The single-point mutation in the acetohydroxyacid synthase (AHAS) gene can lead to AHAS-inhibiting herbicide resistance. In this study, the inheritance and molecular characterization of the tribenuron-methyl (TBM)-resistant rapeseed (Brassica napus L.) mutant, K5, are performed. Results indicated that TBM-resistance of K5 was controlled by one dominant allele at a single nuclear gene locus. The novel substitution of cytosine with thymine at position 544 in BnAHAS1 was identified in K5, leading to the alteration of proline with serine at position 182 in BnAHAS1. The TBM-resistance of K5 was approximately 100 times that of its wild-type ZS9, and K5 also showed cross-resistance to bensufuron-methyl and monosulfuron-ester sodium. The BnAHAS1544T transgenic Arabidopsis exhibited higher TBM-resistance than that of its wild-type, which confirmed that BnAHAS1544T was responsible for the herbicide resistance of K5. Simultaneously, an allele-specific marker was developed to quickly distinguish the heterozygous and homozygous mutated alleles BnAHAS1544T. In addition, a method for the fast screening of TBM-resistant plants at the cotyledon stage was developed. Our research identified and molecularly characterized one novel mutative AHAS allele in B. napus and laid a foundation for developing herbicide-resistant rapeseed cultivars.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2006
Author(s):  
David P. Horvath ◽  
Michael Stamm ◽  
Zahirul I. Talukder ◽  
Jason Fiedler ◽  
Aidan P. Horvath ◽  
...  

A diverse population (429 member) of canola (Brassica napus L.) consisting primarily of winter biotypes was assembled and used in genome-wide association studies. Genotype by sequencing analysis of the population identified and mapped 290,972 high-quality markers ranging from 18.5 to 82.4% missing markers per line and an average of 36.8%. After interpolation, 251,575 high-quality markers remained. After filtering for markers with low minor allele counts (count > 5), we were left with 190,375 markers. The average distance between these markers is 4463 bases with a median of 69 and a range from 1 to 281,248 bases. The heterozygosity among the imputed population ranges from 0.9 to 11.0% with an average of 5.4%. The filtered and imputed dataset was used to determine population structure and kinship, which indicated that the population had minimal structure with the best K value of 2–3. These results also indicated that the majority of the population has substantial sequence from a single population with sub-clusters of, and admixtures with, a very small number of other populations. Analysis of chromosomal linkage disequilibrium decay ranged from ~7 Kb for chromosome A01 to ~68 Kb for chromosome C01. Local linkage decay rates determined for all 500 kb windows with a 10kb sliding step indicated a wide range of linkage disequilibrium decay rates, indicating numerous crossover hotspots within this population, and provide a resource for determining the likely limits of linkage disequilibrium from any given marker in which to identify candidate genes. This population and the resources provided here should serve as helpful tools for investigating genetics in winter canola.


1977 ◽  
Vol 57 (3) ◽  
pp. 937-943 ◽  
Author(s):  
BAHRAM GRAMI ◽  
B. R. STEFANSSON ◽  
R. J. BAKER

The estimates of broad sense heritability in the F2 generation derived from a cross involving two summer rape (Brassica napus L.) cultivars were approximately 0.26 for each of percent protein and percent oil, and 0.33 for the "sum" of protein and oil as a percentage of the seed. The number of effective factors conditioning parental differences in percent protein, percent oil, and sum were estimated as five to seven, one, and two, respectively. Average phenotypic and genotypic correlations between protein and oil content were −0.81 and −0.71, respectively. These strong negative correlations, often considered undesirable, can be utilized in oilseed breeding programs by selecting for the sum of protein and oil rather than for either component.


Genome ◽  
1995 ◽  
Vol 38 (2) ◽  
pp. 414-416 ◽  
Author(s):  
P. K. Tanhuanpää ◽  
J. P. Vilkki ◽  
H. J. Vilkki

The F2 progeny (64 individuals) from the cross between oilseed rape (Brassica napus L.) cultivar Topas and R4 (a low linolenic mutation line) was analyzed with 8 RFLPs and 34 RAPDs to discover a genetic tag for gene(s) affecting linolenic acid concentration. According to variance analysis (ANOVA), one RAPD marker (25a) was significantly associated with linolenic acid content; the linolenic acid concentration in the seeds of F2 individuals showing the marker (includes both homo- and hetero-zygotes) was 7.43 ± 1.35% and in those lacking the marker was 5.70 ± 1.52%. Marker 25a may be used to facilitate selection for fatty acid composition in future breeding programs of oilseed rape.Key words: Brassica napus, RFLP, RAPD, linolenic acid.


2007 ◽  
Vol 58 (8) ◽  
pp. 759 ◽  
Author(s):  
Yuanyuan Li ◽  
Jinxiong Shen ◽  
Tonghua Wang ◽  
Qingfang Chen ◽  
Xingguo Zhang ◽  
...  

Yield is one of the most important traits in Brassica napus breeding programs. Quantitative trait loci (QTLs) for yield-related traits based on genetic mapping would help breeders to develop high-yield cultivars. In this study, a genetic linkage map of B. napus, containing 142 sequence-related amplified polymorphism (SRAP) markers, 163 functional markers, 160 simple sequence repeat (SSR) markers, and 117 amplified fragment length polymorphism (AFLP) markers, was constructed in an F2 population of 184 individuals resulting from the cross SI-1300 × Eagle. This map covered 2054.51 cM with an average marker interval of 3.53 cM. Subsequently, QTLs were detected for 12 yield-related traits in Wuhan and Jingmen. In total, 133 QTLs were identified, including 14 consistent ones across the 2 locations. Fifteen of 20 linkage groups (LGs) were found to have QTLs for the 12 traits investigated, and most of the QTLs were clustered, especially on LGs N2 and N7, where similar QTL positions were identified for multiple traits. Eight of 10 QTLs for yield per plant (YP) were also associated with number of seeds per silique (SS), number of siliques per plant (SP), and/or 1000-seed weight (SW). In addition, 45 functional markers involved in 39 expressed sequence tags (ESTs) were linked to the QTLs of 12 traits. The present results may serve as a valuable basis for further molecular dissection of agronomic traits in B. napus, and the markers related to QTLs may offer promising possible makers for marker assisted selection.


2008 ◽  
Vol 88 (5) ◽  
pp. 951-996 ◽  
Author(s):  
R. H. Gulden ◽  
S. I. Warwick ◽  
A. G. Thomas

Brassica napus and B. rapa are native to Eurasia. In Canada, these species are commonly referred to as volunteer canola, while feral populations of B. rapa are referred to as birdrape. Brassica napus and B. rapa have been grown commercially for their seed oil content in western Canada since the middle of the last century and volunteer populations are common in fields. Escaped populations of both species are also found along roadways, railways and in waste areas; however, only B. rapa is known to have naturalized, self-sustaining feral populations in these habitats in eastern Canada. Despite these escaped and feral populations, B. napus and B. rapa are mainly a concern in agricultural fields where their combined relative abundance has increased over the past few decades. In the mid 1990s, herbicide-resistant genotypes of B. napus were released for commercial production. Herbicide-resistance and the stacking of genes in volunteer populations conferring resistance to multiple herbicides have contributed to increased difficulties in controlling volunteer B. napus in some crops. However, yield loss resulting from volunteer populations is not well documented in Canada. Key words: Brassica napus, Brassica rapa, herbicide resistance, transgene escape, volunteer canola, weed biology


Author(s):  
Tao Yan ◽  
Yao Yao ◽  
Dezhi Wu ◽  
Lixi Jiang

Abstract Rapeseed (Brassica napus L.) is a typical polyploid crop and one of the most important oilseed crops worldwide. With the rapid progress on high-throughput sequencing technologies and the reduction of sequencing cost, large-scale genomic data of a specific crop have become available. However, raw sequence data are mostly deposited in the sequence read archive of the National Center of Biotechnology Information (NCBI) and the European Nucleotide Archive (ENA), which is freely accessible to all researchers. Extensive tools for practical purposes should be developed to efficiently utilize these large raw data. Here, we report a web-based rapeseed genomic variation database (BnaGVD, http://rapeseed.biocloud.net/home) from which genomic variations, such as single nucleotide polymorphisms (SNPs) and insertions/deletions (InDels) across a world-wide collection of rapeseed accessions, can be referred. The current release of the BnaGVD contains 34,591,899 high-quality SNPs and 12,281,923 high-quality InDels and provides search tools to retrieve genomic variations and gene annotations across 1,007 accessions of worldwide rapeseed germplasm. We implement a variety of built-in tools (e.g., BnaGWAS, BnaPCA, and BnaStructure) to help users perform in-depth analyses. We recommend this web resource for accelerating studies on the functional genomics and screening of molecular markers for rapeseed breeding.


Sign in / Sign up

Export Citation Format

Share Document