Study On The Biology Characteristics Of Autotetraploid Pol CMS Line And Its Maintainer Line In Non-Heading Chinese Cabbage

The diploid and autotetraploid Pol CMS lines and its corresponding maintainer lines were studied on the characteristics of anatomy,physiological and biochemical, photosynthetic properties,agronomy,nutrition quality,and other heterosis characteristics. The results were as follows:1.Anther development was observed using a light microscope through paraffic slices on the Pol CMS line and the corresponding maintainer line in autotetraploid non-heading Chinese cabbage,which were induced from the diploid Pol CMS line and corresponding maintainer line by colchicines.The result indicated there was a difference on anther development between Pol CMS line and its corresponding maintainer line.The anther development of the autotetraploid Pol CMS line was inhibited at the stage of archesporial cell,at which there was no anther sac formed and no differentiation of sporogenous cell.A few anthers of autotetraploid Pol CMS line could produce one or two anther sacs under low temperature,which decreased the number of mature pollens due to the tapetum degradated earlier than the normal in the tetrad stage.The anther development of autotetraploid Pol CMS line maintainer line was similar to that of diploid,among which the microspores in autotetraploid were larger than those in diploid with mainly four germination apertures,one more than that in diploid in the same stage.In the same anther sac of autotetraploid Pol CMS maintainer line,the development of pollen grains wasn't synchronized and the frequence of Pollen abortion was higher than that in diploid maintainer line.The study showed the autotetraploid Pol CMS line had more thorough sterility and wider application than diploid Pol CMS line.2.The content of soluble sugar,soluble protein,praline,malondialdehyde (MDA),the activities of peroxidase(POD),superoxide dismumse(SOD),and catalase(CAT) in the buds during different development stages and flowering leaf were studied among Pol CMS lines and its corresponding maintainer lines in diploid and autotetraploid non-heading Chinese cabbage.The result showed:the content of soluble sugar,soluble protein and praline in Pol CMS lines were significant lower than its corresponding maintainer lines both in diploid and autotetraploid,the content of soluble sugar,soluble protein and praline in autotetraploid Pol CMS line buds were lower than those in corresponding diploid;The content of MDA in Pol CMS lines were higher than its corresponding maintainer lines,and there were very significant in large buds.The content of MDA in autotetraploid buds were lower than those in corresponding diploid;The activities of POD,SOD and CAT in Pol CMS lines buds were significant higher than those in corresponding maintainer lines except the activities of SOD in small buds,which were significant lower than its corresponding maintainer lines both in diploid and autotetraploid.The content of soluble protein,soluble sugar and praline in flowering leaf of Pol CMS lines were slightly higher than its corresponding maintainer lines,and it were also a little higher in autotetraploid buds,but there were all no significant differences.The content of MDA and the activities of POD,SOD,CAT in Pol CMS lines were higher than those in its corresponding maintainer lines both in diploid and autotetraploid,and in autotetraploid buds were lower than those in corresponding diploid buds;There were obviously difference of POD and EST electrophoretic analysis of isozyme between the Pol CMS lines and its corresponding maintainer lines both in diploid and autotetraploid,but there was no difference between the diploid and autotetraploid material.3.Photosynthesis characteristics were studied among the diploid and autotetraploid Pol CMS lines and its corresponding corresponding maintainer lines of non-heading Chinese cabbage,the autotetraploid Pol CMS line and its maintainer line were induced from the diploid Pol CMS line and corresponding maintainer line by colchicines.The result showed the content of chlorophyll,the net photosynthetic rate(Pn),the stomatal conductance(Gs),the intercellular CO₂ concentration(Ci),transpiration rate(Tr) of autotetraploid Pol CMS line and its maintainer line were significantly higher than those of diploid,but other photosynthesis indexes including the stoma limit ratio(Ls) and the water use efficiency(WUE) between the diploid and autotetraploid materials were all not significantly different.In the same level of ploid,indexes above were all not significantly different between the Pol CMS lines and its corresponding maintainer lines;With the increase of light intensities,the Pn and Gs were also increased while the Ci were decreased slowly, when the light intensities were over 200μmol m^-2s^-1,the Pn,Gs,Ci of autotetraploid Pol CMS line and its maintainer line were all higher than those of diploid;The parameters of light saturation point(LSP),light compensation point(LCP),apparent quantum yield (AQY),apparent dark respiration rate(Rd),and maximum net photosynthetic rate (Pmax) of autotetraploid Pol CMS line and its maintainer line were higher than those of diploid.The reason of higher Pn of autotetraploid Pol CMS line and its maintainer line was caused by the stoma factor.4.Agronomic traits and application research were taken between the Pol CMS lines and the corresponding maintainer lines both in autotetraploid and diploid non-heading Chinese cabbage.The result indicated the autotetraploid material was higher than diploid,plant diameter became larger,leaf became thicker,leaf area became larger,Yield of plot was increased,and the differences was significant;Disease resistance was enhanced and the quality characters was significant improved;The autotetraploid Pol CMS line had more thorough sterility;seeding capacity of the autotetraploid material was significantly decreased;The heterosis in autotetraploid Pol CMS line were quite extensive and apparent and the heterosis of agronomic traits was strong but that of quality character was not obvious.