Effects of Phosphorus Supply on the Leaf Photosynthesis, and Biomass and Phosphorus Accumulation and Partitioning of Canola (Brassica napus L.) in Saline Environment

Long Wang,Jingdong Zheng,Guang Yang,Jing Li,Qingsong Zuo,Jingjing You,Chen Qian,Suohu Leng

doi:10.3390/agronomy11101918

Abstract

Salt stress is a major negative factor affecting the sustainable development of agriculture. Phosphorus (P) deficiency often occurs in saline soil, and their interaction inhibits plant growth and seed yield for canola (Brassica napus L.). P supply is considered an effective way to alleviate the damage of salt stress. However, the knowledge of how P supply can promote plant growth in saline environment was limited. A field experiment was conducted to explore the effects of P rate on accumulation, and partitioning, of biomass and P, leaf photosynthesis traits, and yield performance in saline soil in the coastal area of Yancheng City, Jiangsu Province, China, during the 2018–2019 and 2019–2020 growing seasons. P supply increased biomass and P accumulation in all organs, and root had the most increments among different organs. At flowering stage, P supply increased the biomass and P partitioning in root and leaf, but it decreased the partitioning in stem. At maturity stage, P supply facilitated the biomass and P partitioning in seed, but it decreased the partitioning in stem and shell, and it increased the reproductive-vegetative ratio, suggesting that P supply can improve the nutrients transporting from vegetative organs to reproductive organs. Besides, P supply improved the leaf area index and photosynthetic rate at the flowering stage. As a result, the seed yield and oil yield were increased. In conclusion, P supply can improve the canola plant growth and seed yield in a saline environment. P fertilizer at the rate of 120 kg P2O5 ha−1 was recommended in this saline soil.

Highlights

Introduction published maps and institutional affilCanola (Brassica napus L.) is an important oil crop, providing rich edible oil for human consumption and a source of protein for animal feed [1]
The results of ANOVA showed that P rate and experimental year affected seed yield, seed oil concentration, oil yield, and most seed yield components except 1000-seed weight; in addition, P rate affected the number of primary branches per plant; the interaction between P rate and the experimental year did not affect any parameters in (Table 2)
Our results showed that an increase in P rate caused decreases in the P partitioning in shell but increases in seed, suggesting that P supply can improve the capacity of the nutrients transporting from shell to seed

Summary

Introduction

Introduction published maps and institutional affilCanola (Brassica napus L.) is an important oil crop, providing rich edible oil for human consumption and a source of protein for animal feed [1]. As one of the largest canola producers, China accounts for more than 20% of the total planting area around the world [2]. Most of its planting area, located in the Yangtze River mid- and low-basin, was estimated at 7 million hectares [3]. In China, canola seed offers about 50% of domestic vegetable oil. Ensuring the sustainable development of canola production is of great significance for the domestic edible oil market. It is estimated that about 1.5 billion hectares of irrigated land, and 1–2% of arid land, are becoming unsuitable for cultivation due to being salinized [4]. Soil salinization has become a severe problem impeding the sustainable development of agriculture in the iations

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Discussion

Conclusion