Impact of nitrogen supply on leaf water relations and physiological traits in a set of potato (Solanum tuberosumL.) cultivars under drought stress

Abstract

Improved adaptation of potato to limited water availability is needed for stable yields under drought. The maintenance of the cell water status and protection of cellular components against dehydration are important for drought tolerance, and the N status of plants affects the regulation of various respective metabolic processes. A 2‐year pot trial with 17 potato cultivars was conducted under a rain‐out shelter including two water regimes and two N‐levels to investigate genotypic differences concerning osmotic adjustment (OA) and relevant biochemical traits in relation to nitrogen (N) supply. Drought stress resulted in a rapid decrease in the leaf osmotic potential. The N, protein and proline contents increased under drought, while the N protein/NKjeldahl ratio decreased. Initially, total soluble sugars increased at both N‐levels but dropped back to the control level at high N‐availability under prolonged drought while remaining high in N‐deficient plants. Results indicate that potatoes have only a limited capacity of active OA and that increasing sugar and proline concentrations are rather associated with the protection of cellular components. High N supply promoted the N protein/NKjeldahl ratio at short‐term drought and enhanced proline accumulation. Significant genotypic differences were observed for all investigated traits.

Contribution of Glycine Betaine and Proline to Water Deficit Tolerance in Pepper Plants

“…The increase was also observed in different pepper cultivars from 6 to 24 d (Anjum et al, 2012) and in tomato cultivars (Moles et al, 2018). Similar studies performed for different cultivars of potato by Meise et al (2018) report that when the plants were subjected to water stress for long periods of time (12 d), they had a greater accumulation of Pro and higher RWC. The authors concluded that there was a genetic variation in the cultivars regarding the treatments they evaluated, and that the roots may have systems that allow the transportation of Pro to be accumulated in leaves or roots.…”

Optimizing Nitrogen Fertilization to Improve Qualitative Performances and Physiological and Yield Responses of Potato (Solanum tuberosum L.)

“…This is because the environmental (most importantly water availability and temperature) and agro-economic conditions are less favourable than those in the Northern European countries where most of the cultivars have been developed [7]. In southern Italy (Sicily, Campania and Apulia), as in other Mediterranean coastal areas, such as North African countries, Cyprus and Turkey, the potato crop is not grown in the usual main cycle (spring-summer), owing to the high temperatures and considerable demand for irrigation water, but is mostly cropped in a winter-spring cycle (planting from November to January and harvesting from March to early June) with the aim of obtaining an early product [8][9][10]. This is highly appreciated for its specific qualitative traits [11,12] and so profitably exported to northern European countries for fresh consumption [13].…”

“…Nevertheless, literature still lacks on comprehensive studies including several aspects, from physiology to yield and quality responses of potato crop in relation to N fertilization. In addition, despite some works dealing with main potato crop response to N fertilization [10,16,20,21,24,28], no attempts have been focused on defining the effects of different N fertilization rates on both the crop physiology, yield and tuber chemical composition of early potato. Indeed, the environmental conditions associated with early potato production substantially modify the morphology and phenology of the crop, and thus the tubers are essentially immature and so differ qualitatively from those produced in the main crop cycle [11].…”

Climatic changes and potatoes: How can we cope with the abiotic stresses?

“…However, a lower rate of chlorophyll degradation was detected on a drought-tolerant cultivar (Rolando et al 2015). Nitrogen content also increases in response to drought stress, and genotype-related differences in this variable have also been investigated (Meise et al 2018).…”