Studies On Creating Cytoplasmic Male Sterile Lines Of Brassica Oleracea Var.acephala D.C. And The Hereditary Characters Of Generations

The objective of this study was to produce cytoplasmic male sterile (CMS) lines of ornamental kales (Brassica oleracea L. var. acephala DC). Ornamental kales were used as paternal plants and CMS zicaitais (Brassica campestris L. var. purpurea Baity), CMS Chinese cabbages (B. campestris ssp. pekinensis) and CMS cabbages (B. oleracea var. capitata) were used as maternal plants. The pollens of ornamental kales were treated with laser or under high-voltage electrostatic field to improve the compatibility in interspecific and intraspecific hybridization. The results were as follows.1. Combination of CMS zicaitais and ornamental kales: Hybrid plants were produced at first step by obtaining ovules by overcoming incompatibility using pollens irradiated for 3 minutes with a laser for pollination, and a second step by applying an ovule culture technique. In all hybrids, the shape and color of leaves looked between those of their parent plants, and the number of chromosome was 19 without exception. The anthers began to abort at the stage of mononuclear pollen. Hybrid plants must be vernalized to make flowers. A most efficient culture medium in view of germination rate and seedling growth was Murashige and Skoog medium +0.2 mg.L-1 6-benzyladenine.2. Combination of CMS Chinese cabbages and ornamental kales: Hybrids were produced by overcoming incompatibility using pollens treated for 30 minutes under high-voltage electrostatic field at 100kv/m for pollination. In all hybrids, the shape and color of leaves looked between those of their parent plants, and the number of chromosome was 19 without exception. The anthers began to abort at the stage of tetrads or mononuclear pollen. Hybrid plants must be vernalized to make flowers.3. Combination of cabbages and ornamental kales: The rate of seed setting was increased to a certain extent by pollination with pollen treated in three ways, i.e., pollen irradiated for 5minutes with laser (J5), pollen treated for 30minutes under high-voltage electrostatic field at lOOkv.m-1 (E2) and pollen treated for 30minutes under high-voltage electrostatic field at 75 kv.m-1 combined with laser irradiation for 3minutes (EJ). EJ treatment was most effective, followed by E2 and J5. Additionally, a 1000-seed weight was increased to a certain extent by all treatments. In BC1 progenies,CMS lines were produced. They were similar to ornamental kales in shape and color of leaves, and their anthers began to abort at the stage of two-nuclear pollen. 4. The primer, the sequence of which was 5' GGC AGT TCT C 3', showed a highly reproducible difference between DNA samples from hybrids and those of parents in repeated experiments. A specific DNA fragment of about 630bp was present in all hybrids from CMS zicaitais x ornamental kales. Another specific DNA fragment of about 500bp was present in all hybrids between CMS Chinese cabbages x ornamental kales. The two specific DNA fragments indicated the authenticity of hybrids.