Salinity and Water Stress Effects on Biomass Production in Different Arundo donax L. Clones

Abstract

Perennial rhizomatous grasses are regarded as leading energy crops due to their environmental benefits and their suitability to regions with adverse conditions. In this paper, two different experiments were carried out in order to study the salinity (S) and water stress (WS) effects on biomass production in giant reed (Arundo donax L.). In Experiment 1, eight clones of giant reed were subjected to four S and WS treatments: (i) well-watered with nonsaline solution, (ii) water stress with non-saline solution, (iii) well-watered with saline solution and iv) water stress with saline solution. In Experiment 2, five clones of giant reed were subjected to increasing S levels in two locations: University of Catania (UNICT-Italy) (i)well-watered with non-saline solution and (ii)wellwatered with mild saline solution; and University of Barcelona (UB-Spain) (iii)well-watered with non-saline solution and (iv)well-watered with severe saline solution. Photosynthetic and physiological parameters as well as biomass production were measured in these plants. According to our data, giant reed seems to be more tolerant to S than WS. Both stresses mainly affected stomatal closure to prevent dehydration of the plant, and eventually decreasing the photosynthetic rate. The differential performance of the giant reed clones was ranked according to their tolerance to S and WS by using the Stress Susceptibility Index. 'Agrigento' was the most WS resistant clone and 'Martinensis' was the most S resistant. 'Martinensis' and 'Piccoplant' were found to be the most suitable clones for growing under both stress conditions. Moreover, 'Fondachello', 'Cefalú' and 'Licata' were the most resistant clones to increasing S levels.Keywords: Arundo donax L.; biomass; water stress; salinity stress; photosynthesis; Stress Susceptibility Index. ABBREVIATIONSA sat , light saturated net CO 2 assimilation rate (µmol m -2 s -1 ); DLP, complete dry leaves percentage (%); DM, dry matter (g); FC, field capacity; g s , stomatal conductance (mol m -2 s -1 ); gLA, green leaf area (m 2 ); GLP, complete green leaves percentage (%); H, height (cm); LAR, leaf area ratio (m 2 Kg -1 ); LWR, leaf weight ratio (Kg Kg -1 ); NL, number of leaves; NS, number of stems; PPFD, photosynthetic photon flux density; PRG, perennial rhizomatous grasses; RWC, relative water content (%); S, salinity; SA, stem area (m 2 ); SLA, specific leaf area (m 2 Kg -1 ); S/R, shoot/root ratio (g g -1 ); SSI, stress susceptibility index; TDW, total dry weight (g); WS, water stress; YLP, complete yellow leaves percentage (%).3

Giant reed genotypes from temperate and arid environments show different response mechanisms to drought

“…Before both transplanting and re-sprouting, at the onset of second growing season, 100 kg ha −1 of N and P were applied in each rhizotron as urea and superphosphate, respectively. The average maximum and minimum air temperatures for the experimental periods (from April to October, 2014 and2015), measured with a portable weather station (iMetos, Pessl Instruments, Austria) were 26.0 ± 5.6 ∘ C and 14.9 ± 3.9 ∘ C for the 2014 growing season and 21.6 ± 9.5 ∘ C and 11.3 ± 6.8 ∘ C for the 2015 growing season, respectively. The average relative humidity was 70 ± 13% and 74 ± 17% in 2014 and 2015, respectively.…”

“…However, its physiological adaptation mechanisms to drought (DR) remain very little known, especially at the root level. Moreover, recent studies indicated restricted variability in overall water use and CO 2 gas exchange, and therefore biomass yield, in response to water stress of several giant reed genotypes (Mann et al 2013, Nackley et al 2014, Sanchez et al 2015, Pompeiano et al 2016, Romero-Munar et al 2017, Haworth et al 2017c. Even though such restricted variability could be related to the limited epigenetic variability among giant reed genotypes (Cosentino et al 2006, Ahmad et al 2008, Mariani et al 2010, Pilu et al 2014, Haworth et al 2017b, 2017c, Haworth et al (2017b) found different adaptive hydraulic stem conductivities in giant reed genotypes (the ones used in the present study) from two contrasting environments (Morocco and Northern Italy), due to the species plasticity to adapt to the prevailing climatic conditions and common abiotic stress in the respective regions of origin.…”

Drought stress and carbon assimilation in a warming climate: Reversible and irreversible impacts

“…Therefore the reversibility of damages is a key aspect in this context and is the focus of this review. Throughout stress and recovery phases, the photosynthetically active biomass per plant and the net CO2 assimilation rate per biomass unit are key parameters (Morales et al, 2014;Sanchez et al, 2015). Leaf expansion and leaf senescence are relevant for the photosynthetically active biomass per plant (LunaFlores et al, 2015;Chen et al, 2015a;Marquez-Garcia et al, 2015).…”

Influence of salt stress on propagation, growth and nutrient uptake of typical aquatic plant species

“…Seven aquatic plant species were used in this study (Table 1), because they are common aquatic plants and known to exhibit salt tolerance to some extent (Calhoun and King 1998, Hunter et al 2000, Mudalige and Longstreth 2006, Sanchez et al 2015, Liang et al 2017a, Liu et al 2018, Xue et al 2018. All species were collected as mature plants from wild populations in Suqian, Jiangsu Province of China in July 2016.…”