Effects of Scion Variety on the Phosphorus Efficiency of Grafted Camellia oleifera Seedlings

Jin Zeng,Xiaomin Guo,Aowen Xu,Ling Zhang,Dongnan Hu,Wenyuan Zhang,Juan Liu,Lunan Lian

doi:10.3390/f13020203

Jin Zeng, Xiaomin Guo + Show 6 more

Open Access

https://doi.org/10.3390/f13020203

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Abstract

Grafting provides a way to improve tolerance to low phosphorus (P) stress for plants, and has been extensively applied in commercial cultivars grafted onto appropriate rootstocks. However, little literature is available concerning the scion-mediated effect on P efficiency in grafted plants. In this study, three different Camellia oleifera Abel. scion cultivars (G8, G83-1, and W2) were grafted onto the same rootstock (W2) under controls (0.5 mM) and low-P (0 mM) availability for eight months. The results showed that the scions significantly affected root-to-shoot weight ratios, the root morphology with a diameter larger than 1 mm, P accumulation, and the P utilization efficiency (PUE) of the root. A higher increase in the root-to-shoot weight ratio under the low-P supply was observed in the G83-1/W2 (26.15%) than in the G8/W2 (0%) and the W2/W2 (5.32%). Root PUE of the scion G8, G83-1, and W2 was improved by up to 113.73%, 45.46%, and 20.97% under the low-P supply. Moreover, G8/W2 exhibited higher shoot P accumulation and the highest root PUE under the low-P supply, indicating a high capability to tolerate P deficiency by maximizing the cost-effectiveness of P remobilization to photosynthetic organs. This suggested the vigorous variety of G8 could be a promising scion to improve grafted C. oleifera tolerance to low-P stress. Our results would have important implications for exploration and identification of a superior scion variety to enhance the ability of resistance concerning P deficiency stress in C. oleifera.

Highlights

Phosphorus (P), as an important component of macromolecular substances, which include nucleic acid and the cytomembrane, is intimately involved in plant growth and development [1,2]
We evaluated the shoot dry weight (SDW) and the root dry weight (RDW) among grafted C. oleifera with different scions on the same rootstocks under control and low-P
The results showed that the RDWs were not altered among different scions of grafted C. oleifera in either treatment (Figure 2a)

Summary

Introduction

Phosphorus (P), as an important component of macromolecular substances, which include nucleic acid and the cytomembrane, is intimately involved in plant growth and development [1,2]. Even when soil total P is relatively high, only 10–25% is available for plants owing to P’s immobilization in soil [3,4]. Application of P fertilizers is required to improve and maintain crop yields worldwide, but only 10–20% of applied P fertilizer is directly utilized by plants [5,6,7]. The remaining P fertilizer is wasted and results in the loss of resources and surface water P pollution. As such, balancing the relationship between the amount of applied P fertilizer and P utilization of plants has been gaining extensive attention among policymakers and plant scientists

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