Fine roots for uptake and translocation of zinc into young leaves as important traits for zinc efficiency of maize genotypes

ABSTRACT

Suitable germplasm and breeding for zinc (Zn)-efficient genotypes has been prioritized to combat Zn deficiency problem. Six maize genotypes were grown in a nutrient solution with or without Zn to identify genotype tolerance to low Zn and its mechanism. Zhongnong 99 was found to be about 2-fold more Zn-efficient than L69 × 178. Young shoot Zn concentration and content was significantly correlated with Zn efficiency (ZE). Furthermore, Zn-efficient genotype as Zhongnong 99 distributed more Zn into young parts of shoot and also developed longer and thinner roots (≤ 0.2 mm) under -Zn conditions than inefficient genotypes. The close relationship (0.82***, 0.88***, 0.90***) between Zn content of young shoots and fine roots indicated that fine roots (≤ 0.2 mm) contributed more efficient Zn uptake into old parts which distributed to young parts. In conclusion, the analysis of young shoots and fine roots (≤ 0.2 mm) represent a suitable screening technique for ZE evaluation of under -Zn conditions.

KEYWORDS:

• Fine roots
• maize
• screening technique
• zinc deficiency
• zinc efficiency

Additional information

Funding

This research was funded by grants from the National Science Foundation of China (31672240), 973 Project (2015CB 150402), China Agriculture Research System (CARS-02) and the Innovative Group Grant of National Science Foundation of China (31421092). The first author is grateful to the China Scholarship Council (CSC) for providing PhD scholarships. The authors are also grateful to Dr Khwaja Hossain from Mayville State University, USA for valuable suggestions and correction of the English.