Establishment And Study For Nuclear And Cytoplasmic Male Sterile Lines Of Brassica Napus L.

Male sterile plants were found in the progenies of the intergeneric hybrids by crossing Brassica napus or Brassica juncea to Orychophragmus violaceus, respectively. After inbred crossing for several times, four nuclear male sterile lines, G585, G587, G590 and G591 were bred. Several male sterile plants found in the progenies of the intergeneric hybrids by crossing Brassica napus to Orychophragmus violaceus had been backcrossed for 4 times with double-low varieties of B. napus, Huashuang 3 and Shuang 72 and 6-2015-1 (the maintainer of Pol CMS), and 405A, 407A and 409A were established. One sterile plant found in the self-cross colony of Jian 3 had been backcrossed for 3 times with Huashuang 3 and 434A was created. Sterile characters, morphology, cytology, qualitative traits, relations of maintainers and restorers of the male sterile lines above were studied in the experiment. The main results are as follows.1. There were visible differences between sterile plants and normal plants in the offspring of inbred cross for these nuclear male sterile lines in the flower morphology. The ratio between androeciums and pistils of 405A, 407A, 409A and Pol CMS was less than 1:2 and their petals kept separated and were smaller than their maintainers. There were a few dead buds in 407A and 409A and a great lot of dead buds in the plants of Pol CMS, while there was no dead buds in 405A and 434A. The morphology of the flower for 434A was similar to its maintainer and the ratio between androecium and pistil was about 1:1.2. The results of the fertility identification in different phases for these male sterile lines showed that there was no pollen in the entire flowering period for these nuclear male sterile lines and 434A which was cytoplasmic male sterile (CMS) line. There was a bit of pollen in anthers for 405A, 407A, 409A and Pol CMS in the early flower phase and no pollen in the late flowering phase.3. The contents of erucic acid and glucosinolates in rapeseed for 405A, 407A and 434A were close to the double-low standards. It was, hence, considered that these three CMS lines were double-low sterile lines.4. The results of cytological observations indicated that somatic chromosome number was 38 in different nuclear male sterile lines. Most of pollen mother cells (PMC) in sterile plants were normal for the chromosome behaviour. But some abnormal phenomena of chromosome, which present as chromosome lagging and bridge, could still be found at each stage of meiosis for several PMC. These nuclear male sterile lines belonged to complete sterile type. The somatic chromosome number for 405A, 407A and 409A were 38, which were considered as the type of B. napus. The observations of cytology for 405A, 407A, 409A and Pol CMS revealed their anthers had no clinandrium and regarded as the sterile type of no clinandrium. The inhibition development of the anther in 434A whose anther had normal clinandrium occurred at the stage of uninucleic pollen,...