Phenotypic, biochemical and genomic variability in generations of the rapeseed (Brassica napus L.) mutant lines obtained via chemical mutagenesis.

The phenotypic, biochemical and genetic variability was studied in M2-M5 generations of ethyl methansulfonat (EMS, 0.2%) mutagenized rapeseed lines generated from canola, '00', B. napus cv. Vikros. EMS mutagenesis induced extensive diversity in morphological and agronomic traits among mutant progeny resulted in selection of EMS populations of B. napus- and B. rapa-morphotypes. The seeds of the obtained mutant lines were high-protein, low in oil and stabilized in contents of main fatty acids which make them useful for feed production. Despite the increased level of various meiotic abnormalities revealed in EMS populations, comparative karyotype analysis and FISH-based visualization of 45S and 5S rDNA indicated a high level of karyotypic stability in M2-M5 plants, and therefore, the obtained mutant lines could be useful in further rapeseed improvement. The revealed structural chromosomal reorganizations in karyotypes of several plants of B. rapa-type indicate that rapeseed breeding by chemical mutagenesis can result in cytogenetic instability in the mutant progeny, and therefore, it should include the karyotype examination. Our findings demonstrate that EMS at low concentrations has great potential in rapeseed improvement

From Dimness to Glossiness—Characteristics of the Spring Rapeseed Mutant Form without Glaucous Bloom (Brassica napus L.)

As a result of the treatment of “Vikros” spring canola with the chemical mutagen ethyl methanesulfonate (EMS), a high-protein mutant form without glaucous bloom (wax bloom) on leaves, shoots, and siliques was isolated. Segregation into glossy and glaucous forms was always observed in the progeny of glossy plants from self-pollination, and the proportion of glaucous plants could reach up to 25%. The progeny of glaucous plants were homogeneous and did not segregate. If during the period of seed germination and seedling development the soil did not dry out and remained moist, and the average daily temperature did not exceed 16 °C, then the amount of glossy plants could reach 99%. Glossy plants possessed qualities valuable for breeding forage varieties, such as the increased content of protein in seeds (more than 30%), and change phenol metabolism, чтo прoявляется a reduced amount of lignin and sinapine in comparison with the original cultivar. In addition, plants without wax coating showed weakened shoot growth, decreased pollen fertility and seed production, and reduced lignin content in the shoots. Glossy mutants are of interest for the obtaining of fodder low-sinapine and low-lignin varieties of spring rapeseed