Potential for recovery of Campomanesia xanthocarpa Mart. ex O. berg seedlings from water deficit

Abstract

The objective of this study is to evaluate the effect of water deficit and the recovery potential following rehydration, on the metabolism of Campomanesia xanthocarpa seedlings. The seedlings were distributed in two groups: the first group was the control, in which, plants were hydrated periodically in order to maintain 70% water holding capacity and the second was the treatment group characterized by stress, in which irrigation was suspended until the photosynthetic rate showed levels close to zero, at which point the plants were once again rehydrated with subsequent daily irrigation for one week, maintaining the water holding capacity at 70%. C. xanthocarpa shows a reduction in stomatal conductance and photosystem PSII efficiency. Water deficit decreases the water potential in the leaves and all the traits of the photosynthetic metabolism in C. xanthocarpa seedlings in twenty days of suspension of irrigation. These are later recovered with the re-establishment of the water supply. However, exposure of the seedlings to a second cycle of water deficit during the evaluation period demonstrated that the metabolism traits do not re-establish equilibrium.

Shading minimizes the effects of water deficit in Campomanesia xanthocarpa (Mart.) O. Berg seedlings

“…According to the literature, the trend of the chlorophyll index with respect to water deficit is variable, however, decreased in C. xanthocarpa under water deficit and did not recover after hydration (Bento et al, 2016), which contrasts with the results observed for the same species in this study.…”

“…Similar results have been reported by Bento et al (2016) for C. xanthocarpa seedlings, in which POD and SOD activities were higher in the leaves in the 1 st and 2 nd P0. In studies with generalist species, which are widely distributed and abundant owing to their plasticity, regarding habitat specificity, POD and SOD activities have been evaluated.…”

“…The results suggest the occurrence of photo-inhibitory damage to the reaction centres of photosystem II, causing a reduction in photosynthesis in this period of stress. A similar reduction in Fv/Fm was observed by Bento et al (2016) for the same species under water deficit; a significant decline in the photosynthetic rate was also found, which might be related to the reduction in electron transfer.…”

“…This result emphasizes the reduction of the functionality of the photosynthetic apparatus because of the damage to the reaction centre of photosystem II or reduction in the transfer capacity of the excitation energy from the antenna to the reaction centre (Maxwell and Johnson, 2000;Baker, 2008). Thus, we observed that chlorophyll a fluorescence characteristics were detected in periods when the plants were stressed, and this is reliable for evaluating plants of other species (Maxwell and Johnson, 2000;Rohácek, 2002;Baker and Rosenqvist, 2004;Bento et al, 2016).…”

Gas Exchange in Caryocar Brasiliense Cambess Seedlings in Water Deficit Conditions

“…A number of researchers have examined the effects of water deficits on different plant species to determine their tolerance mechanisms (Bento et al, 2016;Franco, 2006;Gonçalves et al, 2009;Junglos et al, 2016;Mariano et al, 2009;Medrano et al, 2002;Pacheco et al, 2011;Parry, 2002). The results of these investigations have been useful in arboreal species plantation projects and they could be used to enhance silvicultural techniques for species such as Caryocar brasiliense Cambess, a tropical tree of the Caryocaceae family.…”