Studies On Male Sterilizing Effect Of Chemicals On Rapeseed

The approaches of heterosis utilization in rapeseed consist of three-lines and two-lines. The three-lines is exploiting of cytoplasm male sterility and producing hybrids. The main ways of two-lines utilization are chemical hybridizing agents(CHA)and ecotypical male sterile line. In the study, six chemicals were detected to induce male sterility in rapeseed, then in which BHL was found to be a novel CHA. The spraying pattern was explored. The effect of BHL on agronomic traits and seed production were also investigated. Meanwhile by light microscope, transmission electron microscope and PAS ,which was used to locate starch grain (or polysaccharide),the study was to understand the relationship between defects of cell microstructure and ultra-structure, the distribution of polysaccharide in anthers, and the sterility of rapeseed anthers induced by CHA. The results were described as follows:1. Chemicals selection: a good CHA, named BHL, was found among six kinds of chemicals in 2007 and 2008. But carfentrazone—ethy, ethephon , MCPA—Na, Bensulfuron methyl and growth regulator(containing Brassinolide, Indole-3-ylacetic acid, Gibberellic acid) induced lower male sterility than 75% or no male sterility in this experiment.2. Spraying pattern: BHL with concentration range of 0.3-0.7μg/mL induced 90%-100% male sterility. Especially 0.3μg/mL BHL, first sprayed with 6-8mL per plant at the stage of late mono-nucleus microspore and done again with 3-4mL per plant at mature period, induced 100% full male sterile plants. Seed production was barely effected. However, transient male fertility appeared during initial and terminal flowering.3. Species difference: the sensitivity of different species is a little different to the concentrations of BHL. In the study, 1102 is slightly more sensitive than L635 and 143C.4. Control over trace amount pollens: BHL apparently decreased flowers with trace amount pollens of CMS lines and efficiently increased to 100% male sterility. CMS line 203A and 208A in Brassica napus L. , treated by BHL with concentrations of 0.3μg/mL and 0.5μg/mL ,caused both 100% controlling trace amount pollens in 2008. Seed production was not effected seriously by 0.3μg/mL BHL.5. microstructure and ultra-structure showed that anther abortion of rapeseed induced by BHL happened at each period. It is concluded that whole anther development were effected by CHA. Tapetum demonstrated aberrant in the whole anther development and was presumably the main organization leading to anther abortion. 6. No polysaccharide particles or little polysaccharide particles appeared in whole anther at mature period. Male sterility induced by CHA and distribution of polysaccharide were closely interconnected.