Abstract:

The homologous normal line (M line, the maintainer of CMS line) of Brassica napus L. was chosen as control to investigate the differences of morphological and yield characteristics between the CMS lines and CIMS lines (chemical induced CMS derived from the maintainer lines). Three groups of materials were used including Shaan2A (CMS), Shaan3A (CMS), and Shaan5A (CMS) with their corresponding CIMS and M lines. The chemical SX-1 was sprayed twice at budding and flower-starting periods. Results showed that, compared to the M lines, leaf areas of CIMS lines were less than their M lines at the flowering stage. The plant height of CIMS lines was lower, but the difference reduced gradually. The shapes of flower organs were different with lighter and smaller buds, and shorter stamens. But the shape of silique was not changed. The branching position, main inflorescence length and silique amount of main inflorescence of the CIMS lines were lower, but the branches amount was higher. Biological output, root weight were higher, and the economic coefficient was lower. Seed yield and root-to-top ratio had no difference with the M lines. The fruiting characteristics had no difference after artificial or open pollination. Compared to the CMS lines, leaf areas of CIMS lines were less at the flowering stage. The plant height of CIMS lines was lower before the blooming period, and the difference increased gradually. Silique length, width, surface and amount were larger, but the silique surface of single plant was lower. Branching position, branch number, siliques on braches and main inflorescence length were lower. But the amount and density of siliques were higher on the main inflorescence with higher proportion of siliques on the main inflorescence. The economic coefficient and biological output of CIMS were lower than the CMS lines, while root weight and root-to-top ratio CIMS were higher. The results suggested that, it is very important to establish new compound pollination control system using both CIMS and CMS to integrate the advantages of the two sterile materials.

Key words: Brassica napus L., Chemical induced male sterility (CIMS), Homonuclear cytoplasmic male sterility （CMS）, Morphology and yield characteristics, Compound pollination control system