Accurate identification and correlation analysis of iron and zinc contents in soybean core accessions

Objective Aiming at the malnutrition problem caused by iron (Fe) and zinc (Zn) minerals deficiency for Chinese people, it is significant to conduct the accurate identification of Fe and Zn contents in soybean core accessions.

Method The 163 domestic and foreign soybean core accessions were planted in teaching base of South China Agricultural University consecutively in the early season from 2019 to 2020. The contents of two trace elements of Fe and Zn in the sample grains, were measured by flame atomic absorption spectrometer method, and the correlation analysis was carried out.

Result There were significant differences in the contents of two trace elements between the test years (P<0.05). The variation range of grain Fe content of soybean germplasm resources in two years was 71.02−147.91 mg·kg⁻¹, the average Fe content was 107.09 mg·kg⁻¹, and the variation range of grain Zn content was 36.32−53.11 mg·kg⁻¹, the average content of Zn was 42.80 mg·kg⁻¹. There was a positive correlation between Fe and Zn contents in grains of 163 soybean lines from different sources in different years, indicating that there was a strong mutual promotion between two elements. The mineral contents of 163 soybean accessions were divided into five grades by probability grading method, namely extremely low, low, medium, high and very high. And four soybean accessions with high Fe content, four with high Zn content, five with low Fe content, six with low Zn content and two with high Fe and Zn contents were screened out.

Conclusion The soybean core accessions screened with high/low Fe and Zn content in this study can not only be used for breeding new accessions rich in Fe and Zn content, but also provide the valuable materials for elucidating the genetic basis of functional and new nutrition accessions, and accelerate the use of soybean core accessions and promote the development of soybean production in the South China area.