Abstract:

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.

Key words: Brassica napus, Cadmium accumulation, Field condition, Phytoremediation