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EMS Induction of Early Flowering Mutants in Spring Rape ( Brassica napus )
Author(s) -
Thurling N.,
Depittayanan V.
Publication year - 1992
Publication title -
plant breeding
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.583
H-Index - 71
eISSN - 1439-0523
pISSN - 0179-9541
DOI - 10.1111/j.1439-0523.1992.tb00118.x
Subject(s) - biology , vernalization , brassica , locus (genetics) , cultivar , mutant , bolting , inbred strain , photoperiodism , gene , botany , genetics , horticulture , agronomy
Studies were undertaken to induce early flowering mutants by ethyl methanesulphonate (EMS) treatments of Brassica napus seeds. EMS treatments for 12 h of a highly inbred B. napus line TBS had adverse effects on M 1 plant development and fertility only when concentrations were greater than 1%. However, an EMS concentration of 1.5% did not reduce M 1 plant fertility to an extent which significantly reduced production of M 2 seeds. Genetic changes induced by EMS treatment and affecting flowering time were of three main types: (1) Changes within a polygenic system reflected by increased variation in flowering time among M 2 families. As the increase in variation was due primarily to a higher frequency of later flowering plants, these polygenic changes would be of little value in developing better‐adapted cultivars. (2) Induction of a recessive mutation at a major gene locus which caused M 3 plants homozygous for the mutant gene to flower at least 20 days earlier than the parental line TB8. (3) Induction of a dominant mutation at a major gene locus which affects flowering time by causing a substantial reduction in vernalization requirement. M 2 plants carrying the mutant gene flowered as early as 59 days before the parental line. These major gene mutations could be rapidly exploited in the development of agronomically superior cultivars for short‐season, lower rainfall environments in Western Australia.