Nitrogen Use Efficiency of Watermelon Grafted onto 10 Wild Watermelon Rootstocks under Low Nitrogen Conditions

Abstract

Nitrogen availability is the key determinant of plant growth and development. The improvement of nitrogen use efficiency (NUE) in crops is an important consideration. In fruit and vegetables, such as watermelon, rootstocks are often utilized to control soil borne diseases and improve plant performance to a range of abiotic stresses. In this study, we evaluated the efficacy of 10 wild watermelon rootstocks (ZXG-516, ZXG-941, ZXG-945, ZXG-1250, ZXG-1251, ZXG-1558, ZXG-944, ZXG-1469, ZXG-1463, and ZXG-952) to improve the plant growth and nitrogen use efficiency (NUE) of the watermelon cultivar: Zaojia 8424. Nitrogen use efficiency (NUE) is a comprehensive parameter that represents the ability of a plant to absorb nitrogen (N) and convert the supplied resources to the dry biomass. Wild watermelon rootstocks substantially improved plant growth, rate of photosynthesis, stomatal conductivity, intercellular carbon dioxide concentration, rate of transpiration, nitrogen uptake efficiency, nitrogen use efficiency, and nitrogen utilization efficiency of watermelon. NUE of watermelon grafted onto ZXG-945, ZXG-1250, and ZXG-941 was improved by up to 67%, 77%, and 168%, respectively, at optimum N supply. Similarly, at low N supply (0.2 mM), NUE of watermelon grafted onto ZXG-1558 and ZXG-516 was improved by up to 104% and 175%, respectively. In conclusion, grafting onto some wild rootstocks can improve nitrogen use efficiency of watermelon, and this improved nitrogen use efficiency could be attributed to better N uptake efficiency of wild watermelon rootstocks.

Reducing the nitrate content of burley tobacco by grafting with flue-cured tobacco

“…However, grafting burley tobacco onto ue-cured tobacco (E/K) improved the growth of burley tobacco, indicating rootstock indeed had signi cant in uence on scion growth to some extent. The results are in line with that of Huang Yuan [24 , who reported that grafting with wild watermelon rootstocks with high nitrogen use e ciency substantially improved whole plant growth.…”

Transcriptome analysis reveals the inhibitory nature of high nitrate during adventitious roots formation in the apple rootstock

“…The availability of nutrients is a crucial factor in root development, and nitrate ions regulate the growth and root architecture of higher plants (M'hamdi et al, 2016; Nawaz, Chen, et al, 2018; Nawaz, Han, et al, 2018; Stitt, 1999). External nitrate induces dual effects on root growth both at doze, a stimulatory effect at a low level, and a systemic inhibitory effect at high nitrate concentration.…”

Relationships between Rootstock-Scion Combinations and Growing Regions on Watermelon Fruit Quality

“…The four Citrullus rootstocks that we have used in this work, particularly the citron watermelon PI 482318, rendered improved fruit quality to their dessert watermelon scions after 4 days at 21 • C when compared to that of fruits harvested from plants on the 'Shimshon' pumpkin rootstock ( Table 2). It is highly likely that wild and cultivated citron watermelon genotypes can become valuable rootstocks for dessert watermelon production, because they have good grafting compatibility and have no negative impact on fruit quality when compared to other rootstocks, such as some cultivars of bottle gourd (genus Lagenaria) and pumpkin, as reported by Nawaz et al [18,19]. Furthermore, the potential use of wild citron watermelon rootstocks was reported by Thies et al [20].…”