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SUMMARY: Induced mutations are an essential source of genetic variation in plant breeding. Ethyl methanesulfonate (EMS) mutagenesis has been frequently applied, and mutants have been detected by phenotypic or genotypic screening of large populations. In the present study, a rapeseed M2 population was derived from M1 parent cultivar 'Express' treated with EMS. Whole genomes were sequenced from fourfold (4×) pools of 1988 M2 plants representing 497 M2 families. Detected mutations were not evenly distributed and displayed distinct patterns across the 19 chromosomes with lower mutation rates towards the ends. Mutation frequencies ranged from 32/Mb to 48/Mb. On average, 284 442 single nucleotide polymorphisms (SNPs) per M2 DNA pool were found resulting from EMS mutagenesis. 55% of the SNPs were C → T and G → A transitions, characteristic for EMS induced ('canonical') mutations, whereas the remaining SNPs were 'non‐canonical' transitions (15%) or transversions (30%). Additionally, we detected 88 725 high confidence insertions and deletions per pool. On average, each M2 plant carried 39 120 canonical mutations, corresponding to a frequency of one mutation per 23.6 kb. Approximately 82% of such mutations were located either 5 kb upstream or downstream (56%) of gene coding regions or within intergenic regions (26%). The remaining 18% were located within regions coding for genes. All mutations detected by whole genome sequencing could be verified by comparison with known mutations. Furthermore, all sequences are accessible via the online tool 'EMSBrassica' (http://www.emsbrassica.plantbreeding.uni‐kiel.de), which enables direct identification of mutations in any target sequence. The sequence resource described here will further add value for functional gene studies in rapeseed breeding. Significance Statement: We report on the distribution of induced mutations across a complex crop genome. We found that mutations are non‐randomly spread across the genome. Moreover, the manuscript describes a suitable approach and presents an online database for identifying rapeseed ethyl methanesulfonate mutants on a whole genome scale. This will serve as a valuable resource for rapeseed functional genomics and breeding. [ABSTRACT FROM AUTHOR]

The effective inclusion of rapeseed protein products as fishmeal alternatives in diets for carnivorous fish is still limited. Previous studies observed restrictions in both nutrient utilization and feed intake. Contents of nitrogen‐free extracts (NfE) and anti‐nutritive substances (ANFs) were made responsible for the latter mentioned limitations. Consequently, a highly purified rapeseed protein isolate with high protein content and low levels of both NfE and ANF was investigated in this study. In the first experiment, digestibility of the rapeseed protein isolate was determined. In the second experiment, the fishmeal portion (190 g kg‐1) of a control diet was gradually replaced by rapeseed protein isolate to 33%, 66% and 100% of digestible protein and energy. Diets were fed twice per day to apparent satiation to triplicate groups of rainbow trout (Oncorhynchus mykiss). After 56 days of feeding, growth performance and health parameters were evaluated. Protein digestibility of the rapeseed protein isolate was 95.2%, and up to 66% of dietary fishmeal could be replaced without significantly affecting growth or health parameters. Total replacement of fishmeal led to significantly reduced feed intake and consequently reduced growth performance. [ABSTRACT FROM AUTHOR]

Summary: Plant‐based oils are valuable agricultural products, and seed oil content (SOC) is the major yield component in oil crops. Increasing SOC has been successfully targeted through the selection and genetic modification of oil biosynthesis. The SOC in rapeseed declined during the seed maturation and eventually caused the final accumulated seed oil quantity. However, genes involved in oil degradation during seed maturity are not deeply studied so far. We performed a candidate gene association study using a worldwide collection of rapeseed germplasm. We identified SEED FATTY ACID REDUCER (SFAR) genes, which had a significant effect on SOC and fatty acid (FA) composition. SFAR genes belong to the GDSL lipases, and GDSL lipases have a broad range of functions in plants. After quantification of gene expression using RNA‐seq and quantitative PCR, we used targeted (CRISPR‐Cas mediated) and random (chemical) mutagenesis to modify turnover rates of seed oil in winter rapeseed. For the first time, we demonstrate significant increase of SOC in a crop after knocking out members of the BnSFAR4 and BnSFAR5 gene families without pleiotropic effects on seed germination, vigour and oil mobilization. Our results offer new perspectives for improving oil yield by targeted mutagenesis. [ABSTRACT FROM AUTHOR]

Key message: This study elucidates the influence ofindehiscentmutations on rapeseed silique shatter resistance. A phenotype with enlarged replum-valve joint area and altered cell dimensions in the dehiscence zone is described.Abstract: Silique shattering is a major factor reducing the yield stability of oilseed rape (Brassica napus). Attempts to improve shatter resistance often include the use of mutations in target genes identified from Arabidopsis (Arabidopsis thaliana). A variety of phenotyping methods assessing the level of shatter resistance were previously described. However, a comparative and comprehensive evaluation of the methods has not yet been undertaken. We verified the increase of shatter resistance in indehiscent double knock-down mutants obtained by TILLING with a systematic approach comparing three independent phenotyping methods. A positive correlation of silique length and shatter resistance was observed and accounted for in the analyses. Microscopic studies ruled out the influence of different lignification patterns. Instead, we propose a model to explain increased shattering resistance of indehiscent rapeseed mutants by altered cell shapes and sizes within the contact surfaces of replum and valves. [ABSTRACT FROM AUTHOR]

A kairomone from white mustard, Sinapis alba , that attracts infective juveniles (J2) of the beet cyst nematode, Heterodera schachtii, was extracted from root exudates and enriched by rotary evaporation. The kairomone-containing root exudate fractions were then repeatedly enriched and separated on a combination of octyl and octadecyl columns, leaving a single UV-absorbing HPLC peak. Glucose and fructose were identified by a subsequent HPLC separation in the ion moderated partition chromatography mode. The kairomone appeared in the fructose-containing fraction. As fructose did not cause nematode attraction, the fructose fraction contained at least one further substance. HPLC separations showed that the kairomone shares several properties with fructose and that it is relatively more polar than those compounds giving an UV signal. The repeated reversed-phase and ion moderated partition chromatography separations of single kairomone-containing fractions indicate that the kairomone is composed of one single substance which could not be identified with the methods applied. Gas chromatographic and mass spectrometric analyses revealed the presence of glucose, fructose, myo-inositol, sucrose and xylofuranose/ribofuranose in S. alba root exudates. [ABSTRACT FROM AUTHOR]