Relationship between Low Iron Stress and Iron Efficiency of Soybean Varieties

We took the iron-efficient and iron-inefficient soybean varieties with significant differences in iron efficiency as the test materials, in order to ascertain the relationship between the low iron stress and the iron efficiency of soybean varieties. The results showed that through the principal component analysis, it was found that the contribution rate of the shoot light energy absorption factor and root morphological factor was the highest, reaching 41.0% and 67.2%, respectively. According to the eigenvector with high absolute value for the two factors, it was found that improving photosynthesis and root surface area could help to improve the ability of soybean to resist low iron. From the dynamic simulation results of Logistic equation, both V and Vm of the shoot and root of iron-efficient varieties were higher than those of iron-inefficient varieties; the low iron treatment postponed the time of the root of iron-inefficient varieties to reach Vm, while the iron-efficient varieties were resistant to the damage caused by the low iron to growth by improving root V. However, when the iron concentration was 0 mM, regardless of iron-efficient varieties or iron-inefficient varieties, the shoot V, Vm and △t were all low, indicating that the division of different iron efficiency varieties was relative, not absolute, and the ability of plant to resist stress was not only determined by its own characteristics, but also closely related to the degree of stress.