Environmentally-Related Cherry Root Cambial Plasticity

Abstract

The general aim of this research was to determine whether the cherry root cambium possesses similar water-stress adaptation abilities as the scion. Specifically, this study aimed to determine whether there is a shift in root xylem structure due to precipitation fluctuations and temperature increase during the growing season in two cherry species. Oblačinska sour cherry and European ground cherry roots with secondary structure were anatomically surveyed in detail, and correlated with meteorological conditions occurring during the vegetation when the roots were formed. Under environmental signals, both investigated species altered their radial root growth imprinting stops and starts in a cambial activity that resulted in the occurrence of intra-annual false growth rings. Changing environmental conditions triggered the shifts of large and small vessels throughout the false growth rings, but their size seemed to be mainly genetically controlled. Taking into consideration all the above, genotypes with moderate vessel lumen area—lesser or around 1200 μm2 in the inner zone, as well as no greater than 1500 μm2 in the outer zone—are presumed to be both size-controlling and stable upon the drought events. Thus, further field trials will be focused on the SV2 European ground cherry genotype, and OV13, OV32, and OV34 Oblačinska sour cherry genotypes.

Investigation of stem anatomy in relation to hydraulic conductance, vegetative growth and yielding potential of ‘Summit’ cherry trees grafted on different rootstock candidates

“…Since investigated stems were of the same age, sampled from the same part of the plant and grown in the same environmental setting, SDs are presumed to be strongly genetically dependent as previously noted for eucalyptus (Bartholomé et al, 2020). High heritability and genetic control of anatomical traits and water use efficiency was previously noted by Lauri et al (2011) as well as Lopez et al (2017). Lesser variation in CSA was observed in scion stems in comparison with the rootstock stems, indicating that to some extent scion retains its scionspecific cambial activity.…”

“…Thus, higher V e of trees on P. cerasus rootstock candidates in comparison with control trees could be due to higher susceptibility of trees on 'Gisela 5' to water scarcity during the drought events, which might have resulted in suppressed tree growth. Since 'Gisela 5' is considered as low-vigour inducing (Lang, 2000), our results showed that all investigated rootstock candidates are potentially dwarfing.…”

“…The abundance of flowers was notably higher on P. cerasus rootstock candidates, which might be due to earlier fruiting phase entering. It was noted that trees on PM_09_01 had a similar number of flowers as trees on P. fruticosa in 2020, with the expectation of significantly higher flower abundance in the following years, since P. mahaleb does not induce high fertility in the first years of fruiting (Lang, 2000). It was observed that the highest number of flowers per tree on PC_05_04 and PC_02_01/4 have resulted from the increased length of fruiting branches in comparison with the branches of trees on 'Gisela 5', which induced the earlier shoot cessation in control trees (Prassinos et al, 2009).…”

“…In these efforts, new generations of lowvigour-inducing rootstocks, which are being constantly improved through various breeding programmes, represent the key factor. Along with the vigour control, reasons for dwarfing rootstocks utilisation are found in their capability to favourably affect fruit precociousness and productivity rate, despite the need for crop loads to leaf area balancing (Lang, 2000, Whiting et al, 2005. Although the wide range of rootstocks is proven to be size-controlling, the exact mechanism of such control is still unresolved.…”