Adaptive diversity in Castanea sativa Mill. half-sib progenies in response to drought stress

Abstract

a b s t r a c tVariation patterns in phenotypic expression after cultivation in two water regimes: 50% and 90% substrate saturation were studied in progenies of chestnut (Castanea sativa Mill.) cultivars originating from two main origins in the Iberian Peninsula: North (specifically from Asturias and Galicia) and Central Iberian Peninsula (specifically from the Canary Islands and Andalusia in Southern Spain related to this gene pool). The restricted water supply reduced the water potential of all the families as well as their growth, both in terms of height and weight. Root development increased whilst leaf area decreased as a result of reduction in number and surface area of individual leaves as well as sprouting rather than through defoliation. Drought stress also modified the morphology of the leaves and the relationships indicating the rate of relative development of the leaves compared to the rest of the plant. A correlation with the minimum summer rainfall in the regions of provenance was observed for several traits. The phenotypic variation observed was greater than expected from progenies of selected fruit cultivars. The results of this study show that (i) phenotypic variation exists between the two origins of variability corresponding to the two identified gene pools; (ii) the Northern group might be considered more tolerant to drought stress when considering plantlets' ability to recover water potential, though important phenotypic plasticity was found in both origins of variability; and (iii) the pattern of variation found in some physiological and morphological traits suggests that Spanish chestnut stands have great potential to respond to the expected increase in drought in the Iberian Peninsula over the present century.

Glacial refugia and mid-Holocene expansion delineate the current distribution of Castanea sativa in Europe

“…The populations of C. sativa in this region also show good adaptation to limiting environmental conditions, e.g. drought, in comparison with the southern Iberian populations (Ciordia et al 2012). This supports the idea that the species colonized central and southern Iberia in the warm and humid period of the mid-Holocene, but later on it was negatively affected by dry summers that characterize this region, particularly by the so-called 4200 cal BP arid event, as well as by the increase of anthropic activities since the Chalcolithic period (López-Sáez et al 2014).…”

Shoot traits and their relevance in terminal drought tolerance of chickpea ( Cicer arietinum L.)

“…But the correlations improved with the advances in growth stage to become significant at close to maturity only in the intense DS year. SLA is well known to be a drought tolerance indicator in many crops ( Nigam et al, 2005 , Arunyanark et al, 2008 , Jongrungklang et al, 2008 , Pimratch et al, 2008 ) but a smaller SLA is considered to be advantageous in groundnut facing more of an intermittent DS ( Wright and Hammer, 1994 , Nageswara Rao et al, 2001 , Painawadee et al, 2009 ) and other crops ( Brown and Byrd, 1996 , Pita and Pardos, 2001 , Ciordia et al, 2012 ). A lower SLA becomes advantageous for a less water loss and a more C exchange ensuring plant survival.…”

Increased tolerance to Phytophthora cinnamomi in offspring of ink-diseased chestnut (Castanea sativa Miller) trees

“…Symptoms are caused by extensive root loss and necrosis in the inner bark of main roots and collar. Castanea sativa is a highly valued multipurpose tree native to Europe, where it covers 2.5 million ha, including cultivated orchards and wild forests with high biodiversity (Ciordia et al 2012;Conedera et al 2016). In Spain, it is probably the most culturally valued tree, but soils of nearly all C. sativa forests are infested by P. cinnamomi (Paloma Abad-Campos, unpublished results).…”

“…will probably be less competitive than non-susceptible species. In droughtprone areas of the Mediterranean basin such as southern and central Spain, climate change is causing temperature rise and water stress events in C. sativa stands (Ciordia et al 2012;Camisón et al 2020). Combined effects of infested soils and water deprivation could further limit the success of C. sativa regeneration in the understory.…”