大田条件下油菜镉积累特征

Characteristics of Cadmium Accumulation in Brassica napus under Field Conditions

油菜具备耐受镉(Cd)污染同时安全生产的潜力。为了给利用油菜进行Cd污染农田的生态修复与安全利用提供理论支持,利用24个全国冬油菜区广泛种植的油菜品种为材料,于2020年10月在湖南省湘潭市农业科学研究所实验基地,采用田间小区试验考察了不同油菜品种根、主茎、分枝、叶、角果皮、籽粒在低浓度污染农田(全Cd含量0.54 mg/kg,有效Cd含量0.23 mg/kg)中对Cd的积累差异。在不同小区土壤中有效Cd含量无显著差异的情况下,油菜成熟期不同组织对Cd的吸收和积累存在差异,其中叶片中平均Cd含量最高,根、茎和角果皮次之;籽粒中Cd含量最低,低于国家规定的食品污染物标准(0.1 mg/kg)。不同油菜品种根中Cd含量无显著差异,但在主茎、分枝、角果皮和籽粒中Cd含量存在差异。对不同品种组织中转运系数进行统计,结果表明,不同油菜品种之间转运系数存在差异,在庆油1号中,叶片、角果皮的转运系数较高,但在籽粒中相对较低,沣油737、扬油9号在分枝和叶片中较高,在籽粒中处于中等。对油菜收获部分单株总Cd含量进行分析,结果表明,华杂62、庆油1号等品种总Cd含量高且籽粒Cd含量低。因此,油菜具有富集Cd的能力,华杂62、庆油1号等品种具备修复农田土壤轻度Cd污染同时安全生产的潜力。

Brassica napus has the potential to tolerate Cadmium(Cd)pollution while producing safely.To provide theoretical support for the ecological restoration and safe utilization of Cd-polluted farmland using B.napus,field plot experiments involved 24 widely grown winter rape varieties were performed in October 2020 at the Agricultural Science Research Institute in Xiangtan City,Hunan Province.Cd accumulation in different tissues of the rape plants grown in low-concentration Cd-polluted farmland(total Cd content 0.54 mg/kg,effective Cd content 0.23 mg/kg)was analyzed.Effective Cd content did not differ significantly among different plots,while there were differences in Cd absorption and accumulation in different tissues of mature rape plants.The highest average Cd content was observed in leaves,followed by roots,stems,and silique walls,while the lowest value was in seeds,which was below the national food pollutant standard(0.1 mg/kg).There was no significant difference in Cd content in roots of different rape varieties,but there were differences in stems,branches,silique walls,and seeds.The transmission coefficients in different tissues of different rape varieties were analyzed,and the results showed that there were differences in transfer coefficients between different varieties.In Qingyou 1,the transmission coefficients in leaves and silique walls were relatively high,but low in seeds.Fengyou 737 and Yangyou 9 had higher transmission coefficients in branches and leaves,and medium values in seeds.The total Cd content in the harvested parts of rape plants was analyzed,and the results indicated that varieties such as Huaza 62 and Qingyou 1 had high total Cd content but low Cd content in seeds.In conclusion,B.napus has the ability to enrich Cd,and varieties such as Huaza 62 and Qingyou 1 have the potential to restore slightly Cd-polluted farmland while ensuring production safety.