Root growth and phosphorus efficiency among sweet potato genotypes under low phosphorus

Abstract

A column experiment was conducted to investigate the responses of root growth and phosphorus (P) efficiency among sweet potatoes—JiHei1 (JH1), NingZi2 (NZ2), SuShu11 (S11) and SuShu17 (S17)—under low P and normal P conditions. Root growth was inhibited by low P in root length and surface area across diameter classes, except for in S17. The P absorption was influenced and led to variations in P content among organs. A high correlation was observed in root dry matter (DM) and P uptake. The tuber DM declined among genotypes under low P, and different P efficiencies were determined. A higher phosphorus utilization efficiency was observed in S11 and S17, suggesting that more P was needed to maintain their normal growth. Physiological efficiency and phosphorus utilization efficiency were significantly positively correlated with the tuber DM, indicating that low P limited the growth of sweet potatoes. These results benefit the production and breeding of sweet potatoes in response to P deficiency.

Keywords:

• dry matter
• phosphorus deficiency
• phosphorus uptake
• root morphology
• sweet potatoes

Acknowledgments

We especially acknowledge Jia ZD for providing the experimental materials and helpful advice.

Additional information

Funding

This research was financially supported by Jiangsu Post-doctoral Research Funding (2018K033A), the Earmarked Fund for China Agriculture Research System (CARS-10-B-9), and the Jiangsu Agricultural Independent Innovation Fund (CX (17)-1001).