Establishment And Identification Of 1~# And 4~# Cabbage-Chinese Cabbage Monosomic Alien Addition Lines

Monosomics and disomics additional lines of plants are the important materials in gene location, physical mapping and chromosome engineering breeding. In this paper, the allotriploid(ACC,2n=3x=28)from the hybridization between diploid Chinese cabbage (AA, 2n=2x=20) and autotetraploid cabbage (CCCC, 2n=4x=36) as materials, the screening and identification of monosomic additional lines of cabbage genome with particular chromosome from Chinese cabbage were carried out by means of microspores culture, backcross, cytological identification and karyotype analysis. The embryoids and plantlets were successfully produced from the isolated microspores of the allotriploid. Two monosomic addition lines were preliminary obtained from the filial individuals of CC×ACC. The monosomic addition lines provide a basic materials for further creating the alien substitution and translocation lines. The main results are listed as follows:1. The induced frequency of microspore embryoids in eight different plants of the allotriploid(ACC) were very low, which indicated that the aneuploid genome in microspores had obvious effect on the microspore embryoid formation. The media and pre-treatments also had distinct effect in microspore regeneration, of which the medium NLN with 15% sucrose , 0.1 mg·L-1 6-BA, 0.2 mg·L-1 2,4-D and 0.05 mg·L-1 KT and the pre-treatment with 33℃culturing 48h had the best result, the embryoids were about 0.0250 per bud.2. The cytological examination showed that chromosome number in the ten microspore plantlets varied from 14 to 27, of which there was one plant with 14 chromosome , one with 20, one with 27, two with 17, two with 19 and three with 18. But the plants adding one or two chromosomes were not obtained. The characters, such as vigour, height, leaf shape, leaf color, flower color, flower shape, flower size, florescence and fertility were different among the microspore plant lines.3. The hybridization of ACC×CC and CC×ACC indicated that the seed setting of ACC×CC combination was about 0.01%,much lower than that(1.60%) of CC×ACC combination. Therefore, the allotriploid(ACC) as male parent was more available for creating the monosomic addition line of cabbage genome with special chromosome from Chinese cabbage.4. Two monosomic addition lines(CC+A1 and CC+A4) were preliminary obtained from 81 plants from CC×ACC by karyotypic analysis and morphological observation.5. The morphological observation showed that the two monosomic addition lines could form head normally, but the characters existed difference between the addition- lines and diploid parent(CK).