The mechanism of increased seed fertility accompanied with the change of flower colour inBrassicoraphanus

✍ Scribed by M. Kato; S. Tokumasu

• Book ID: 104619442
• Publisher: Springer
• Year: 1976
• Tongue: English
• Weight: 382 KB
• Volume: 25
• Category: Article
• ISSN: 0014-2336
• DOI: 10.1007/bf00041616

✦ Synopsis

In Brassicoraphanus (amphidiploids between Brassica japonica SIEB. and Raphanus sativus L.), yellow-flowered plants that occurred among originally white-flowered plants showed an increased seed fertility. It is assumed that the gene Y (yellow-flower gene) from Brassica and the gene W (whiteflower gene) from Raphanus are located at corresponding loci of only partially homologous chromosomes. W is dominant (epistatic) over Y. The normal white-flowered plants have the genotype YYWW. A YYYW-plant was found, which is assumed to have arisen through crossing-over following multivalent formation. In the progeny of this plant, yellow-flowered plants (YYYY) as well as white-flowered plants (YYWW, YYYW) appeared. The gene for flower colour is closely linked to a gene which controls the development of embryos (or endosperm). This gene promotes the development of embryos in homozygous condition. Therefore, the embryo having only the yellow-flower gene can develop more easily into viable seed than the embryo having the white-flower gene. It is also possible that the sterility of white-flowered plants is caused by a discordance between the cytoplasm of Brassica and W (or genes linked to W) of Raphanus.