| In this study,conventional rapeseed varieties(Brassica napus L.)Ningyou 20 and Huashuang 5 were planted under low salt level(salt-ion content was 2.702 g.kg-1)and high salt level(salt-ion content was 4.808 g.kg-1)in 2015?2016 and 2016?2017.The effects of salt-ion content on the growth of rapeseed,accumulation and distribution of carbon,nitrogen and use efficiencies of carbon and nitrogen were studied preliminarily through sampling,measuring dry matter weight,carbon and nitrogen contents,agronomic characters and seed qualities at the beginning flowering and ripen stages.Main results were as following:1.There were significant effects of soil salt-ion content on the yield and seed qualities.With increasing soil salt content,yield and oil content decreased significantly,but protein content increased significantly.The average decline ranges of yield of Ningyou 20 and Huashuang 5 in two years in high soil salt content were 23.71%and 26.17%comparing to those in low soil salt content,respectively.The average decline ranges of oil content were 5.20%and 5.28%,respectively.The average increasing ranges of protein content were 8.94%and 10.37%,respectively.2.With the increase of soil salt content,the whole accumulation amounts of dry matter weight,carbon and nitrogen increased significantly at the beginning flowering and ripen stages.In addition to stem and branches,the accumulation amounts of dry matter weight,carbon and nitrogen in different organs also increased significantly with increasing of soil salt content.With the increase of salt content,the accumulation amounts of dry matter,carbon and nitrogen during before and after the flowering was significantly reduced,and it had a greater impact on the accumulation amount during after the flowering.The average decline ranges of dry matter weight during after flowering stage of Ningyou 20 and Huashuang 5 in two years in high soil salt content were 33.04%and 33.77%comparing to those in low soil salt content,respectively.The average decline ranges of carbon accumulation amount were 37.68%and 38.66%,respectively,and the average decline ranges of nitrogen accumulation amount were 52.66%and 48.56%,respectively.3.At the ripen stage,the distribution proportion of dry matter,carbon and nitrogen in root is smaller than those in other organs,and among them the root nitrogen distribution proportion is the smallest.The distribution proportion of dry matter in stem and branch is the largest in different organs,the change range in different treatments is 23.83%to 30.36%.The proportion of carbon and nitrogen distribution in seed are the highest in different organs,and the change ranges were 27.70%to 32.33%and 47.85%to 55.70%respectively.At the ripen stage,with the increase of soil salt content,the distribution proportions of dry matter,carbon and nitrogen in root and stem and branches increased significantly,and the distribution proportions of them in seeds decreased significantly.The accumulation proportions of dry matter and carbon during before the flowering were less than 50%,and with the increase of salt content the accumulation proportions increased significantly.On the contrary,the accumulation proportions of dry matter and carbon was more than 50%,and with the increase of salt content there were a significant decreasing trend.The nitrogen accumulation proportions during before the flowering were larger than those during after the flowering,and the change range of different treatments was 71.43%to 83.03%.The nitrogen accumulation proportions during after the flowering were small,and the change range of different treatments were 16.97%to 28.57%.With the increase of salt content,the nitrogen accumulation proportions increased significantly during before the flowering,and decreased significantly during after the flowering.4.The carbon translocation rates of root and stem from the flowering stage to the ripen stage were negative,that is to say,the root and stem still accumulated carbon,and the greater the absolute value of its translocation rate,the greater the accumulation proportions.The carbon translocation rates of leaf were positive,which indicated that leaf exported carbon mainly in this period.The range of translocation rates of root in different treatments was-34.05%to-28.75%,and there was no significant difference between different salt treatments.The change range of carbon translocation rate in stem and branches was-55.79%to-40.70%,and with the increase of salt content,the carbon translocation rates of stem and branches decreased significantly,that is to say,the carbon accumulation proportion increased significantly.The variation range of carbon translocation rate in leaf in different treatments was 24.58%to 30.47%,and with the increase of salt content,the carbon translocation rates of leaf decreased,but the differences were relatively small.The nitrogen translocation rates of root were the smallest among different organs,and the change range of nitrogen translocation rate in root was 34.50%to 38.27%,and there was no significant difference between different salt treatments.The change range of nitrogen translocation rate in stem and branches in all treatments was 46.46%to 52.90%,and with the increase of salt content,the nitrogen translocation rate of stem and branches decreased significantly.The decline ratio of the average nitrogen translocation rate in Ningyou 20 and Huashuang 5 in the high salt content treatment were 10.77%and 8.70%,respectively,compared with the low salt content treatment.The nitrogen translocation rate in leaf were the highest in all organs,and the variation range in different treatments was 72.81%to 75.98%.With the increase of the salt content the nitrogen translocation rate of leaf decreased.5.The carbon utilization efficiency for grain production(CUEg)of rapeseed was relatively smaller than the nitrogen utilization efficiency for grain production(NUEg),and the range of CUEg in different treatments varied from 0.490 g.g-1 to 0.571 g.g-1.With the increase of salt content,CUEg was significantly reduced.The decline ratio of CUEg in Ningyou 20 and Huashuang 5 in the high salt content treatment were 11.03%and 10.00%,respectively,compared with the low salt content treatment.The average value of NUEg was 13.77 g.g-1,which was 25.9 times of the average value of CUEg(0.531 g.g-1).Compared with CUEg,the variation range of NUEg was also larger,which was 12.05 g.g-1 to 15.75 g.g-1.With the increase of salt content,NUEg was significantly reduced.The decline ratio of NUEg in Ningyou 20 and Huashuang 5 in the high salt content treatment were 20.43%and 20.18%,respectively,compared with the low salt content treatment. |
PDF Full Text Request