Effects of Salt Stress on Growth, Photosynthesis, and Mineral Nutrients of 18 Pomegranate (Punica granatum) Cultivars

Cuiyu Liu,Zhaohe Yuan,Mengmeng Gu,Junxin Yan,Xueqing Zhao

doi:10.3390/agronomy10010027

Cuiyu Liu, Zhaohe Yuan + Show 3 more

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https://doi.org/10.3390/agronomy10010027

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Abstract

Pomegranate (Punica granatum L.) is widely grown in arid and semiarid regions, where the salinization may have developed through irrigation. A greenhouse experiment was conducted to investigate NaCl stress on growth, photosynthesis, and nutrients of 18 pomegranate cultivars. One group was irrigated twice a week with a nutrient solution. The other group was watered twice a week with the same nutrient solution and 200 mM NaCl for five weeks. Dry weight, shoot length, new shoot number, root length and number, leaf area, leaf relative water content, and net photosynthesis of salt-treated plants were negatively impacted by salt stress, and there was a significant difference among cultivars. Few foliar damages were observed. Na content of plants significantly increased in all cultivars, while P, S, K, Ca, Mg, Si, Al, Zn content of plants decreased under salt stress. Fe, Mn, and Cu content increased in most cultivars. Pomegranate accumulated supraoptimal Na mostly in roots and transported more K and Ca to shoots, which was attributed to maintaining a higher ratio of K/Na and Ca/Na in the aerial part of plants. Ten of the 18 cultivars were considered salt-tolerant, which would offer a reference for pomegranate cultivation on saline lands.

Highlights

Pomegranate (Punica granatum L.) is one of the longest cultivated edible fruit trees, with plenty of nutritional and medicinal benefits [1]
We found soil–plant analyses development (SPAD) values of 11 pomegranate cultivars increased and that of 7 cultivars decreased under salt stress (Table 3, p < 0.05)
Salt treatment impacted pomegranate growth negatively, with a large variation among the 18 cultivars investigated in this study

Summary

Introduction

Pomegranate (Punica granatum L.) is one of the longest cultivated edible fruit trees, with plenty of nutritional and medicinal benefits [1]. Most pomegranate plants are widely grown in arid and semiarid regions, where the salinization may have developed through irrigation [2,3]. Soil salinization has become a considerable limiting factor in agricultural systems [3]. The deleterious effects of salinity on plant growth are associated with osmotic stress, ion toxicity, nutrient deficiency, and/or the combined effects [4,5]. Pomegranate is a salinity tolerant plant [6,7].

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