The use of physiological, biochemical and morpho-anatomical traits in tree breeding for improved water-use efficiency of Quercus robur L.

Abstract

Aim of study: In the present paper we studied the nature and level of co-dependence between leaf functional traits and intrinsic water-use efficiency (WUEi)in one-year-old Quercus roburL. seedlings, grown in a common garden experiment under moderate drought conditions. The study aimed to identify those traits that might be potentially utilized to improve leaf-level WUEi, and therefore be used in breeding programmes to enhance drought adaptation of Q. roburtree species.Area of study: The study was carried out at the common garden experiment established within UNESCO Biosphere Reserve Mura-Drava-Danube.Material and methods: The study involved one-year-old seedlings of eight half-sib lines of Q. robur. We analyzed 18 leaf parameters; i.e. physiological, biochemical, morphological and anatomical. Data were processed using multivariate statistical methods: a) principal component analysis, b) stepwise regression analysis, and c) path coefficient analysis.Main results: The results evidenced that leaf stomatal traits, particularly stomatal density (SD),and leaf dry mass per unit leaf area (LMA) were the most important traits associated closely with WUEi.Stomatal density achieved the highest score on PC1 (0.825), in which WUEihad the highest loading (0.920), as well. SDwas also included first in stepwise regression model. Research highlights: The results demonstrated that under moderate water stressWUEiin Q. robur half-sib lines were mainly the result of the plants’ structural acclimation to surrounding environmental conditions.

Genetic differentiation in functional traits among wild cherry (Prunus avium L.) half-sib lines

“…In addition, there was a significant negative correlation between WUE on one side, and SD, gs and A, on another, suggesting that plants with lower stomatal density tend to have higher water-use efficiencies, as well as reduced CO 2 uptake, and consequently, lower assimilation rates (Drake et al 2013). Our results are also in agreement with the findings of Stojnić et al (2019) who demonstrated that variation of WUE in Q. robur half-sib lines was strongly dependent on both SD and FRAP.…”

“…Based on Pearson's correlation analysis, a significant positive correlation was found between gs and SL (r = 0.53), confirming the results of Dow et al (2014) who found evidence that stomatal conductance is affected by stomatal aperture characteristics. Similar results were also reported by Stojnić et al (2019) for Q. robur half-sib progenies. Likewise, PCA showed a positive relationship between gs and SD, which corresponds to the results for different plant species (Pearce et al 2006;Xu and Zhou 2008).…”

“…were extracted, respectively. Similarly, for the analysis of relationships between parameters, the loadings were calculated with principal components and canonical variables that had eigenvalues higher than 1 (Stojnić et al 2019). In addition, the selected principal components were rotated by the varimax method to maximize variance of loadings within the same principal component.…”

“…Application of multivariate statistical analyses for these purposes has been an efficient way in analyzing large datasets of measured phenotypic traits (Ganopoulos et al 2018). For example, recent studies, performed on different broadleaved tree species grown in common garden experiments, showed that multivariate data analyses is a powerful tool in the assessment of a species genetic variability (Stojnić et al 2016a;Torres-Ruiz et al 2019;Vastag et al 2019), as well as breeding for improved water-use efficiency (Stojnić et al 2019).…”

Magnolia grandiflora L. shows better responses to drought than Magnolia × soulangeana in urban environment

“…Species characterized with higher WUEi values have specific water-saving strategy to avoid greater water losses and maintain higher assimilation rates, particularly important under the conditions of predicted climate changes (Brendel et al 2008). Taking into account the effectiveness of WUEi as an indicator of drought sensitivity, the importance of identification of traits that could be utilized to improve WUEi and hence enhance drought adaptation in breeding programmes was noted (Stojnić et al 2019). M. grandiflora exhibited a higher ability to tolerate the prolonged period of drought compared to M. soulangeana, by maintaining greater values of A and WUEi.…”