Physiological and morphological responses of Prunus species with different degree of tolerance to long-term root hypoxia

EVALUATION OF GAS EXCHANGES IN DIFFERENT Prunus SPP. ROOTSTOCKS UNDER DROUGHT AND FLOODING STRESS

“…The stomatal closure and reduction in post-water stress net photosynthesis have been reported in Prunus (MARTINAZZO et al, 2011;MARTINAZZO et al, 2013;PIMENTEL et al, 2014). In trials where rootstocks of 'GXN-9' hybrid (Prunus dulcis Mill.…”

“…Martinazzo et al (2013) parameters evaluated from the fourth and fifth day of stress, however, on the contrary of the observed in this study with cultivar 'Julior', the plum tree 'America' demonstrated more serious consequences for the water deficit treatment as compared with flooding. In a similar experiment, Pimentel et al (2014) submitted 'Marianna 2624' plants to flooding and, in surveying both A and gs, decreased in the parameters only on the 14 th day of stress and the plants' survival rate were of 100%. However, they recorded maximum temperatures ranging between 25 and 30°C, values well below those occurred in the period of the present study, which peaks were around 42°C.…”

“…towards effects of water stress depend on several factors, such as imposed types of stress (drought or flooding), their time of duration and especially on the level of tolerance of the genotype, which was notably discrepant, especially when comparing different species (peach tree and plum tree). It is known and reported by several authors in the literature, that water stress provides strong impacts to plants' metabolism, the reduction in photosynthetic capacity and stomatal conductance being considered limiting and triggering several other harmful processes (FERNER et al, 2012;PIMENTEL et al, 2014;KREUZWIESER and RENNENBERG, 2014). According to Kreuzwieser and Rennerberg (2014) there are strong indications that limitations on both stomatal and non-stomatal are involved in the progressive reduction of photosynthetic capacity in plants subjected to environmental stresses.…”

“…Such rootstocks can be coming from both peach cultivars and from other species of the genus Prunus, as of plum trees, since grafting compatibility takes places. According to Pimentel et al (2014) species of Prunus are considered sensitive to hypoxia, although, there is variability for the tolerance among different cultivars. Fachinello and Bianchi (2005) related that other fact associated with the poor yield is the model of peach rootstock production which occurs in most cases through the use of stones obtained in agroindustry canned peaches.…”

“…Water stress, both by drought and for flooding, affect the wood plants' metabolism, since gene expression, and the production and consumption of energy until plant growth and development (PIMENTEL et al, 2014). A series of studies has reported that the photosynthetic process is progressively reduced in plants submitted to water stress conditions, at first as a protective effect as well as in consequence of the stomata closure, decrease of the leaf area and decrease of the chlorophyll content in the leaf (MARTINAZZO et al, 2013, PIMENTEL et al, 2014, resulting into significant physiological restraints which can cause severe falls in plant yield (NAKASHIMA et al, 2014).…”