Preliminary Studies On Constructing Brassica Napus L Mutant Library By EMS Inducement

Mutants have been playing important role in crop genetic improvement and functional genomics researches.The present research constructed a mutant library derived from an EMS treatment which had the best inducement effect in 4 EMS concetrations(0%,0.2%, 0.4%,0.6%) treatment of canola line NJ7982 (Brassica napus L) from Nanjing Agricultural University. Through morphorlogical observation, seed quality determination and herbicide resistance evaluation in mutation progenies, phenotype mutants have been recorded and collected, high oleic acid content mutants and herbicide-resistant plants have also been obtained. Main results are as follows.1. Various phenotypic mutants have been obtained. In M2 population,8789 plants with phenotypic mutative traits which were devided into classes such as leaf, flower, plant type, silique and seed coat trait mutants, were observed, accounting for 18.51% of the M2 plants. Cotyledon trait mutants covered tricotyledon. yellowish cotyledon, etc. accounting 0.22% in the M2 population. Leaf trait mutants such as yellowish leaf, albino leaf, purple leaf, up-curly leaf, down-curly leaf, etc, were observed with mutation frequency of 0.74%. Flower trait mutants manifested as purple buds, bud-deads, three petals, six petals, white petal, white-mosaic petal, wrinkled-petal, complete male sterility, few powder, etc, were of 9.38% in the M2 population. Plant type trait mutants included dwarf plant, thick stem, excessive branches, tight type, tufty branches, brown stem, purple stem, premature, etc, accounting for 4.98%. Silique trait mutants accounting for 2.79% included thick-walled silique, long silique. curly silique, purple silique, etc. Fifty yellow-seeded mutants were also obtained, accounting 0.40% in harvested population. All these phenotypic mutation materials were saved in germplasm bank, will be used to benefit rapeseed functional genomics research and variety improvement.2. Germplasm with high oleic acid content was obtained. By determinating seed fatty acid content, screening results showed that seven germplasms with more than 73% oleic acid content in seed oil were obtained from M2 plants with average oleic acid content of 75.18%, higher than 66.65% of its wild type by 8.53%, will be very useful in fatty acid improvement of Brassica napus.3. Herbicide-resistant plants were obtained. By spraying glyphosate, five mutants were alive after treatment from 105 263 seedlings, and the survival rate of seeding reached 0.004% in the population. Evaluation of glyphosate with carious concentrations in M3 showed that the mutation materials were also resistant to herbicide, and provide new materials for herbicide-resistant variety breeding.